mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-15 08:14:15 +08:00
f504465970
449 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Linus Torvalds
|
e2ca6ba6ba |
MM patches for 6.2-rc1.
- More userfaultfs work from Peter Xu. - Several convert-to-folios series from Sidhartha Kumar and Huang Ying. - Some filemap cleanups from Vishal Moola. - David Hildenbrand added the ability to selftest anon memory COW handling. - Some cpuset simplifications from Liu Shixin. - Addition of vmalloc tracing support by Uladzislau Rezki. - Some pagecache folioifications and simplifications from Matthew Wilcox. - A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use it. - Miguel Ojeda contributed some cleanups for our use of the __no_sanitize_thread__ gcc keyword. This series shold have been in the non-MM tree, my bad. - Naoya Horiguchi improved the interaction between memory poisoning and memory section removal for huge pages. - DAMON cleanups and tuneups from SeongJae Park - Tony Luck fixed the handling of COW faults against poisoned pages. - Peter Xu utilized the PTE marker code for handling swapin errors. - Hugh Dickins reworked compound page mapcount handling, simplifying it and making it more efficient. - Removal of the autonuma savedwrite infrastructure from Nadav Amit and David Hildenbrand. - zram support for multiple compression streams from Sergey Senozhatsky. - David Hildenbrand reworked the GUP code's R/O long-term pinning so that drivers no longer need to use the FOLL_FORCE workaround which didn't work very well anyway. - Mel Gorman altered the page allocator so that local IRQs can remnain enabled during per-cpu page allocations. - Vishal Moola removed the try_to_release_page() wrapper. - Stefan Roesch added some per-BDI sysfs tunables which are used to prevent network block devices from dirtying excessive amounts of pagecache. - David Hildenbrand did some cleanup and repair work on KSM COW breaking. - Nhat Pham and Johannes Weiner have implemented writeback in zswap's zsmalloc backend. - Brian Foster has fixed a longstanding corner-case oddity in file[map]_write_and_wait_range(). - sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang Chen. - Shiyang Ruan has done some work on fsdax, to make its reflink mode work better under xfstests. Better, but still not perfect. - Christoph Hellwig has removed the .writepage() method from several filesystems. They only need .writepages(). - Yosry Ahmed wrote a series which fixes the memcg reclaim target beancounting. - David Hildenbrand has fixed some of our MM selftests for 32-bit machines. - Many singleton patches, as usual. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCY5j6ZwAKCRDdBJ7gKXxA jkDYAP9qNeVqp9iuHjZNTqzMXkfmJPsw2kmy2P+VdzYVuQRcJgEAgoV9d7oMq4ml CodAgiA51qwzId3GRytIo/tfWZSezgA= =d19R -----END PGP SIGNATURE----- Merge tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - More userfaultfs work from Peter Xu - Several convert-to-folios series from Sidhartha Kumar and Huang Ying - Some filemap cleanups from Vishal Moola - David Hildenbrand added the ability to selftest anon memory COW handling - Some cpuset simplifications from Liu Shixin - Addition of vmalloc tracing support by Uladzislau Rezki - Some pagecache folioifications and simplifications from Matthew Wilcox - A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use it - Miguel Ojeda contributed some cleanups for our use of the __no_sanitize_thread__ gcc keyword. This series should have been in the non-MM tree, my bad - Naoya Horiguchi improved the interaction between memory poisoning and memory section removal for huge pages - DAMON cleanups and tuneups from SeongJae Park - Tony Luck fixed the handling of COW faults against poisoned pages - Peter Xu utilized the PTE marker code for handling swapin errors - Hugh Dickins reworked compound page mapcount handling, simplifying it and making it more efficient - Removal of the autonuma savedwrite infrastructure from Nadav Amit and David Hildenbrand - zram support for multiple compression streams from Sergey Senozhatsky - David Hildenbrand reworked the GUP code's R/O long-term pinning so that drivers no longer need to use the FOLL_FORCE workaround which didn't work very well anyway - Mel Gorman altered the page allocator so that local IRQs can remnain enabled during per-cpu page allocations - Vishal Moola removed the try_to_release_page() wrapper - Stefan Roesch added some per-BDI sysfs tunables which are used to prevent network block devices from dirtying excessive amounts of pagecache - David Hildenbrand did some cleanup and repair work on KSM COW breaking - Nhat Pham and Johannes Weiner have implemented writeback in zswap's zsmalloc backend - Brian Foster has fixed a longstanding corner-case oddity in file[map]_write_and_wait_range() - sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang Chen - Shiyang Ruan has done some work on fsdax, to make its reflink mode work better under xfstests. Better, but still not perfect - Christoph Hellwig has removed the .writepage() method from several filesystems. They only need .writepages() - Yosry Ahmed wrote a series which fixes the memcg reclaim target beancounting - David Hildenbrand has fixed some of our MM selftests for 32-bit machines - Many singleton patches, as usual * tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (313 commits) mm/hugetlb: set head flag before setting compound_order in __prep_compound_gigantic_folio mm: mmu_gather: allow more than one batch of delayed rmaps mm: fix typo in struct pglist_data code comment kmsan: fix memcpy tests mm: add cond_resched() in swapin_walk_pmd_entry() mm: do not show fs mm pc for VM_LOCKONFAULT pages selftests/vm: ksm_functional_tests: fixes for 32bit selftests/vm: cow: fix compile warning on 32bit selftests/vm: madv_populate: fix missing MADV_POPULATE_(READ|WRITE) definitions mm/gup_test: fix PIN_LONGTERM_TEST_READ with highmem mm,thp,rmap: fix races between updates of subpages_mapcount mm: memcg: fix swapcached stat accounting mm: add nodes= arg to memory.reclaim mm: disable top-tier fallback to reclaim on proactive reclaim selftests: cgroup: make sure reclaim target memcg is unprotected selftests: cgroup: refactor proactive reclaim code to reclaim_until() mm: memcg: fix stale protection of reclaim target memcg mm/mmap: properly unaccount memory on mas_preallocate() failure omfs: remove ->writepage jfs: remove ->writepage ... |
||
|
Linus Torvalds
|
ce8a79d560 |
for-6.2/block-2022-12-08
-----BEGIN PGP SIGNATURE-----
iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmOScsgQHGF4Ym9lQGtl
cm5lbC5kawAKCRD301j7KXHgpi5ID/9pLXFYOq1+uDjU0KO/MdjMjK8Ukr34lCnk
WkajRLheE8JBKOFDE54XJk56sQSZHX9bTWqziar0h1fioh7FlQR/tVvzsERCm2M9
2y9THJNJygC68wgybStyiKlshFjl7TD7Kv5N9Y3xP3mkQygT+D6o8fXZk5xQbYyH
YdFSoq4rJVHxRL03yzQiReGGIYdOUEQQh8l1FiLwLlKa3lXAey1KuxWIzksVN0KK
aZB4QhiBpOiPgDHUVisq2XtyQjpZ2byoCImPzgrcqk9Jo4esvm/e6esrg4xlsvII
LKFFkTmbVqjUZtFjqakFHmfuzVor4nU5f+xb90ZHExuuODYckkxWp5rWhf9QwqqI
0ik6WYgI1/5vnHnX8f2DYzOFQf9qa/rLgg0CshyUODlD6RfHa9vntqYvlIFkmOBd
Q7KblIoK8YTzUS1M+v7X8JQ7gDR2KwygH37Da2KJS+vgvfIb8kJGr1ZORuhJuJJ7
Bl69gaNkHTHrqufp7UI64YXfueeuNu2J9z3zwzGoxeaFaofF/phDn0/2gCQE1fQI
XBhsMw+ETqI6B2SPHMnzYDu2DM1S8ZTOYQlaD4G3uqgWnAM1tG707395uAy5yu4n
D5azU1fVG4UocoNIyPujpaoSRs2zWZycEFEeUQkhyDDww/j4hlHi6H33eOnk0zsr
wxzFGfvHfw==
=k/vv
-----END PGP SIGNATURE-----
Merge tag 'for-6.2/block-2022-12-08' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
- NVMe pull requests via Christoph:
- Support some passthrough commands without CAP_SYS_ADMIN (Kanchan
Joshi)
- Refactor PCIe probing and reset (Christoph Hellwig)
- Various fabrics authentication fixes and improvements (Sagi
Grimberg)
- Avoid fallback to sequential scan due to transient issues (Uday
Shankar)
- Implement support for the DEAC bit in Write Zeroes (Christoph
Hellwig)
- Allow overriding the IEEE OUI and firmware revision in configfs
for nvmet (Aleksandr Miloserdov)
- Force reconnect when number of queue changes in nvmet (Daniel
Wagner)
- Minor fixes and improvements (Uros Bizjak, Joel Granados, Sagi
Grimberg, Christoph Hellwig, Christophe JAILLET)
- Fix and cleanup nvme-fc req allocation (Chaitanya Kulkarni)
- Use the common tagset helpers in nvme-pci driver (Christoph
Hellwig)
- Cleanup the nvme-pci removal path (Christoph Hellwig)
- Use kstrtobool() instead of strtobool (Christophe JAILLET)
- Allow unprivileged passthrough of Identify Controller (Joel
Granados)
- Support io stats on the mpath device (Sagi Grimberg)
- Minor nvmet cleanup (Sagi Grimberg)
- MD pull requests via Song:
- Code cleanups (Christoph)
- Various fixes
- Floppy pull request from Denis:
- Fix a memory leak in the init error path (Yuan)
- Series fixing some batch wakeup issues with sbitmap (Gabriel)
- Removal of the pktcdvd driver that was deprecated more than 5 years
ago, and subsequent removal of the devnode callback in struct
block_device_operations as no users are now left (Greg)
- Fix for partition read on an exclusively opened bdev (Jan)
- Series of elevator API cleanups (Jinlong, Christoph)
- Series of fixes and cleanups for blk-iocost (Kemeng)
- Series of fixes and cleanups for blk-throttle (Kemeng)
- Series adding concurrent support for sync queues in BFQ (Yu)
- Series bringing drbd a bit closer to the out-of-tree maintained
version (Christian, Joel, Lars, Philipp)
- Misc drbd fixes (Wang)
- blk-wbt fixes and tweaks for enable/disable (Yu)
- Fixes for mq-deadline for zoned devices (Damien)
- Add support for read-only and offline zones for null_blk
(Shin'ichiro)
- Series fixing the delayed holder tracking, as used by DM (Yu,
Christoph)
- Series enabling bio alloc caching for IRQ based IO (Pavel)
- Series enabling userspace peer-to-peer DMA (Logan)
- BFQ waker fixes (Khazhismel)
- Series fixing elevator refcount issues (Christoph, Jinlong)
- Series cleaning up references around queue destruction (Christoph)
- Series doing quiesce by tagset, enabling cleanups in drivers
(Christoph, Chao)
- Series untangling the queue kobject and queue references (Christoph)
- Misc fixes and cleanups (Bart, David, Dawei, Jinlong, Kemeng, Ye,
Yang, Waiman, Shin'ichiro, Randy, Pankaj, Christoph)
* tag 'for-6.2/block-2022-12-08' of git://git.kernel.dk/linux: (247 commits)
blktrace: Fix output non-blktrace event when blk_classic option enabled
block: sed-opal: Don't include <linux/kernel.h>
sed-opal: allow using IOC_OPAL_SAVE for locking too
blk-cgroup: Fix typo in comment
block: remove bio_set_op_attrs
nvmet: don't open-code NVME_NS_ATTR_RO enumeration
nvme-pci: use the tagset alloc/free helpers
nvme: add the Apple shared tag workaround to nvme_alloc_io_tag_set
nvme: only set reserved_tags in nvme_alloc_io_tag_set for fabrics controllers
nvme: consolidate setting the tagset flags
nvme: pass nr_maps explicitly to nvme_alloc_io_tag_set
block: bio_copy_data_iter
nvme-pci: split out a nvme_pci_ctrl_is_dead helper
nvme-pci: return early on ctrl state mismatch in nvme_reset_work
nvme-pci: rename nvme_disable_io_queues
nvme-pci: cleanup nvme_suspend_queue
nvme-pci: remove nvme_pci_disable
nvme-pci: remove nvme_disable_admin_queue
nvme: merge nvme_shutdown_ctrl into nvme_disable_ctrl
nvme: use nvme_wait_ready in nvme_shutdown_ctrl
...
|
||
David Hildenbrand
|
f7355e99d9 |
mm/gup: remove FOLL_MIGRATION
Fortunately, the last user (KSM) is gone, so let's just remove this rather special code from generic GUP handling -- especially because KSM never required the PMD handling as KSM only deals with individual base pages. [akpm@linux-foundation.org: fix merge snafu]Link: https://lkml.kernel.org/r/20221021101141.84170-10-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Peter Xu <peterx@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Andrew Morton
|
3b91010500 | Merge branch 'mm-hotfixes-stable' into mm-stable | ||
John Starks
|
fcd0ccd836 |
mm/gup: fix gup_pud_range() for dax
For dax pud, pud_huge() returns true on x86. So the function works as long as hugetlb is configured. However, dax doesn't depend on hugetlb. Commit |
||
|
David Hildenbrand
|
f347454d03 |
mm/gup: disallow FOLL_FORCE|FOLL_WRITE on hugetlb mappings
hugetlb does not support fake write-faults (write faults without write
permissions). However, we are currently able to trigger a
FAULT_FLAG_WRITE fault on a VMA without VM_WRITE.
If we'd ever want to support FOLL_FORCE|FOLL_WRITE, we'd have to teach
hugetlb to:
(1) Leave the page mapped R/O after the fake write-fault, like
maybe_mkwrite() does.
(2) Allow writing to an exclusive anon page that's mapped R/O when
FOLL_FORCE is set, like can_follow_write_pte(). E.g.,
__follow_hugetlb_must_fault() needs adjustment.
For now, it's not clear if that added complexity is really required.
History tolds us that FOLL_FORCE is dangerous and that we better limit its
use to a bare minimum.
--------------------------------------------------------------------------
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <stdint.h>
#include <sys/mman.h>
#include <linux/mman.h>
int main(int argc, char **argv)
{
char *map;
int mem_fd;
map = mmap(NULL, 2 * 1024 * 1024u, PROT_READ,
MAP_PRIVATE|MAP_ANON|MAP_HUGETLB|MAP_HUGE_2MB, -1, 0);
if (map == MAP_FAILED) {
fprintf(stderr, "mmap() failed: %d\n", errno);
return 1;
}
mem_fd = open("/proc/self/mem", O_RDWR);
if (mem_fd < 0) {
fprintf(stderr, "open(/proc/self/mem) failed: %d\n", errno);
return 1;
}
if (pwrite(mem_fd, "0", 1, (uintptr_t) map) == 1) {
fprintf(stderr, "write() succeeded, which is unexpected\n");
return 1;
}
printf("write() failed as expected: %d\n", errno);
return 0;
}
--------------------------------------------------------------------------
Fortunately, we have a sanity check in hugetlb_wp() in place ever since
commit
|
||
|
David Hildenbrand
|
84209e87c6 |
mm/gup: reliable R/O long-term pinning in COW mappings
We already support reliable R/O pinning of anonymous memory. However,
assume we end up pinning (R/O long-term) a pagecache page or the shared
zeropage inside a writable private ("COW") mapping. The next write access
will trigger a write-fault and replace the pinned page by an exclusive
anonymous page in the process page tables to break COW: the pinned page no
longer corresponds to the page mapped into the process' page table.
Now that FAULT_FLAG_UNSHARE can break COW on anything mapped into a
COW mapping, let's properly break COW first before R/O long-term
pinning something that's not an exclusive anon page inside a COW
mapping. FAULT_FLAG_UNSHARE will break COW and map an exclusive anon page
instead that can get pinned safely.
With this change, we can stop using FOLL_FORCE|FOLL_WRITE for reliable
R/O long-term pinning in COW mappings.
With this change, the new R/O long-term pinning tests for non-anonymous
memory succeed:
# [RUN] R/O longterm GUP pin ... with shared zeropage
ok 151 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP pin ... with memfd
ok 152 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP pin ... with tmpfile
ok 153 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP pin ... with huge zeropage
ok 154 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP pin ... with memfd hugetlb (2048 kB)
ok 155 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP pin ... with memfd hugetlb (1048576 kB)
ok 156 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP-fast pin ... with shared zeropage
ok 157 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP-fast pin ... with memfd
ok 158 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP-fast pin ... with tmpfile
ok 159 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP-fast pin ... with huge zeropage
ok 160 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP-fast pin ... with memfd hugetlb (2048 kB)
ok 161 Longterm R/O pin is reliable
# [RUN] R/O longterm GUP-fast pin ... with memfd hugetlb (1048576 kB)
ok 162 Longterm R/O pin is reliable
Note 1: We don't care about short-term R/O-pinning, because they have
snapshot semantics: they are not supposed to observe modifications that
happen after pinning.
As one example, assume we start direct I/O to read from a page and store
page content into a file: modifications to page content after starting
direct I/O are not guaranteed to end up in the file. So even if we'd pin
the shared zeropage, the end result would be as expected -- getting zeroes
stored to the file.
Note 2: For shared mappings we'll now always fallback to the slow path to
lookup the VMA when R/O long-term pining. While that's the necessary price
we have to pay right now, it's actually not that bad in practice: most
FOLL_LONGTERM users already specify FOLL_WRITE, for example, along with
FOLL_FORCE because they tried dealing with COW mappings correctly ...
Note 3: For users that use FOLL_LONGTERM right now without FOLL_WRITE,
such as VFIO, we'd now no longer pin the shared zeropage. Instead, we'd
populate exclusive anon pages that we can pin. There was a concern that
this could affect the memlock limit of existing setups.
For example, a VM running with VFIO could run into the memlock limit and
fail to run. However, we essentially had the same behavior already in
commit
|
||
Jason Gunthorpe
|
53b2d09bdd |
mm/gup: remove the restriction on locked with FOLL_LONGTERM
This restriction was created because FOLL_LONGTERM used to scan the vma
list, so it could not tolerate becoming unlocked. That was fixed in
commit
|
||
Logan Gunthorpe
|
4003f107fa |
mm: introduce FOLL_PCI_P2PDMA to gate getting PCI P2PDMA pages
GUP Callers that expect PCI P2PDMA pages can now set FOLL_PCI_P2PDMA to allow obtaining P2PDMA pages. If GUP is called without the flag and a P2PDMA page is found, it will return an error in try_grab_page() or try_grab_folio(). The check is safe to do before taking the reference to the page in both cases seeing the page should be protected by either the appropriate ptl or mmap_lock; or the gup fast guarantees preventing TLB flushes. try_grab_folio() has one call site that WARNs on failure and cannot actually deal with the failure of this function (it seems it will get into an infinite loop). Expand the comment there to document a couple more conditions on why it will not fail. FOLL_PCI_P2PDMA cannot be set if FOLL_LONGTERM is set. This is to copy fsdax until pgmap refcounts are fixed (see the link below for more information). Link: https://lkml.kernel.org/r/Yy4Ot5MoOhsgYLTQ@ziepe.ca Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20221021174116.7200-3-logang@deltatee.com Signed-off-by: Jens Axboe <axboe@kernel.dk> |
||
|
Logan Gunthorpe
|
0f0892356f |
mm: allow multiple error returns in try_grab_page()
In order to add checks for P2PDMA memory into try_grab_page(), expand the error return from a bool to an int/error code. Update all the callsites handle change in usage. Also remove the WARN_ON_ONCE() call at the callsites seeing there already is a WARN_ON_ONCE() inside the function if it fails. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20221021174116.7200-2-logang@deltatee.com Signed-off-by: Jens Axboe <axboe@kernel.dk> |
||
Peter Xu
|
93c5c61d9e |
mm/gup: Add FOLL_INTERRUPTIBLE
We have had FAULT_FLAG_INTERRUPTIBLE but it was never applied to GUPs. One
issue with it is that not all GUP paths are able to handle signal delivers
besides SIGKILL.
That's not ideal for the GUP users who are actually able to handle these
cases, like KVM.
KVM uses GUP extensively on faulting guest pages, during which we've got
existing infrastructures to retry a page fault at a later time. Allowing
the GUP to be interrupted by generic signals can make KVM related threads
to be more responsive. For examples:
(1) SIGUSR1: which QEMU/KVM uses to deliver an inter-process IPI,
e.g. when the admin issues a vm_stop QMP command, SIGUSR1 can be
generated to kick the vcpus out of kernel context immediately,
(2) SIGINT: which can be used with interactive hypervisor users to stop a
virtual machine with Ctrl-C without any delays/hangs,
(3) SIGTRAP: which grants GDB capability even during page faults that are
stuck for a long time.
Normally hypervisor will be able to receive these signals properly, but not
if we're stuck in a GUP for a long time for whatever reason. It happens
easily with a stucked postcopy migration when e.g. a network temp failure
happens, then some vcpu threads can hang death waiting for the pages. With
the new FOLL_INTERRUPTIBLE, we can allow GUP users like KVM to selectively
enable the ability to trap these signals.
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20221011195809.557016-2-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
||
Mike Kravetz
|
57a196a584 |
hugetlb: simplify hugetlb handling in follow_page_mask
During discussions of this series [1], it was suggested that hugetlb
handling code in follow_page_mask could be simplified. At the beginning
of follow_page_mask, there currently is a call to follow_huge_addr which
'may' handle hugetlb pages. ia64 is the only architecture which provides
a follow_huge_addr routine that does not return error. Instead, at each
level of the page table a check is made for a hugetlb entry. If a hugetlb
entry is found, a call to a routine associated with that entry is made.
Currently, there are two checks for hugetlb entries at each page table
level. The first check is of the form:
if (p?d_huge())
page = follow_huge_p?d();
the second check is of the form:
if (is_hugepd())
page = follow_huge_pd().
We can replace these checks, as well as the special handling routines such
as follow_huge_p?d() and follow_huge_pd() with a single routine to handle
hugetlb vmas.
A new routine hugetlb_follow_page_mask is called for hugetlb vmas at the
beginning of follow_page_mask. hugetlb_follow_page_mask will use the
existing routine huge_pte_offset to walk page tables looking for hugetlb
entries. huge_pte_offset can be overwritten by architectures, and already
handles special cases such as hugepd entries.
[1] https://lore.kernel.org/linux-mm/cover.1661240170.git.baolin.wang@linux.alibaba.com/
[mike.kravetz@oracle.com: remove vma (pmd sharing) per Peter]
Link: https://lkml.kernel.org/r/20221028181108.119432-1-mike.kravetz@oracle.com
[mike.kravetz@oracle.com: remove left over hugetlb_vma_unlock_read()]
Link: https://lkml.kernel.org/r/20221030225825.40872-1-mike.kravetz@oracle.com
Link: https://lkml.kernel.org/r/20220919021348.22151-1-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
|
Linus Torvalds
|
1440f57602 |
Five hotfixes - three for nilfs2, two for MM. For are cc:stable, one is
not. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCY0YhtwAKCRDdBJ7gKXxA juJLAQDCa0g8sfe9cTw3PT1gRnn8gWLHEkMgUWVC/aBaqYFGeQEAta+g8muv9Tpd qODv0JARH4cwONKEA24Oql+A5RnI6gQ= =QZnW -----END PGP SIGNATURE----- Merge tag 'mm-hotfixes-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc hotfixes from Andrew Morton: "Five hotfixes - three for nilfs2, two for MM. For are cc:stable, one is not" * tag 'mm-hotfixes-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: nilfs2: fix leak of nilfs_root in case of writer thread creation failure nilfs2: fix NULL pointer dereference at nilfs_bmap_lookup_at_level() nilfs2: fix use-after-free bug of struct nilfs_root mm/damon/core: initialize damon_target->list in damon_new_target() mm/hugetlb: fix races when looking up a CONT-PTE/PMD size hugetlb page |
||
Baolin Wang
|
fac35ba763 |
mm/hugetlb: fix races when looking up a CONT-PTE/PMD size hugetlb page
On some architectures (like ARM64), it can support CONT-PTE/PMD size hugetlb, which means it can support not only PMD/PUD size hugetlb (2M and 1G), but also CONT-PTE/PMD size(64K and 32M) if a 4K page size specified. So when looking up a CONT-PTE size hugetlb page by follow_page(), it will use pte_offset_map_lock() to get the pte entry lock for the CONT-PTE size hugetlb in follow_page_pte(). However this pte entry lock is incorrect for the CONT-PTE size hugetlb, since we should use huge_pte_lock() to get the correct lock, which is mm->page_table_lock. That means the pte entry of the CONT-PTE size hugetlb under current pte lock is unstable in follow_page_pte(), we can continue to migrate or poison the pte entry of the CONT-PTE size hugetlb, which can cause some potential race issues, even though they are under the 'pte lock'. For example, suppose thread A is trying to look up a CONT-PTE size hugetlb page by move_pages() syscall under the lock, however antoher thread B can migrate the CONT-PTE hugetlb page at the same time, which will cause thread A to get an incorrect page, if thread A also wants to do page migration, then data inconsistency error occurs. Moreover we have the same issue for CONT-PMD size hugetlb in follow_huge_pmd(). To fix above issues, rename the follow_huge_pmd() as follow_huge_pmd_pte() to handle PMD and PTE level size hugetlb, which uses huge_pte_lock() to get the correct pte entry lock to make the pte entry stable. Mike said: Support for CONT_PMD/_PTE was added with |
||
|
David Hildenbrand
|
0cf459866a |
mm/gup: use gup_can_follow_protnone() also in GUP-fast
There seems to be no reason why FOLL_FORCE during GUP-fast would have to
fallback to the slow path when stumbling over a PROT_NONE mapped page. We
only have to trigger hinting faults in case FOLL_FORCE is not set, and any
kind of fault handling naturally happens from the slow path -- where NUMA
hinting accounting/handling would be performed.
Note that the comment regarding THP migration is outdated: commit
|
||
|
David Hildenbrand
|
474098edac |
mm/gup: replace FOLL_NUMA by gup_can_follow_protnone()
Patch series "mm: minor cleanups around NUMA hinting". Working on some GUP cleanups (e.g., getting rid of some FOLL_ flags) and preparing for other GUP changes (getting rid of FOLL_FORCE|FOLL_WRITE for for taking a R/O longterm pin), this is something I can easily send out independently. Get rid of FOLL_NUMA, allow FOLL_FORCE access to PROT_NONE mapped pages in GUP-fast, and fixup some documentation around NUMA hinting. This patch (of 3): No need for a special flag that is not even properly documented to be internal-only. Let's just factor this check out and get rid of this flag. The separate function has the nice benefit that we can centralize comments. Link: https://lkml.kernel.org/r/20220825164659.89824-2-david@redhat.com Link: https://lkml.kernel.org/r/20220825164659.89824-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Liam R. Howlett
|
c4d1a92d0d |
mm/gup: use maple tree navigation instead of linked list
Use find_vma_intersection() to locate the VMAs in __mm_populate() instead of using find_vma() and the linked list. Link: https://lkml.kernel.org/r/20220906194824.2110408-52-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Tested-by: Yu Zhao <yuzhao@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: SeongJae Park <sj@kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Andrew Morton
|
6d751329e7 | Merge branch 'mm-hotfixes-stable' into mm-stable | ||
Yang Shi
|
70cbc3cc78 |
mm: gup: fix the fast GUP race against THP collapse
Since general RCU GUP fast was introduced in commit |
||
|
David Hildenbrand
|
088b8aa537 |
mm: fix PageAnonExclusive clearing racing with concurrent RCU GUP-fast
commit |
||
Alistair Popple
|
67e139b02d |
mm/gup.c: refactor check_and_migrate_movable_pages()
When pinning pages with FOLL_LONGTERM check_and_migrate_movable_pages() is called to migrate pages out of zones which should not contain any longterm pinned pages. When migration succeeds all pages will have been unpinned so pinning needs to be retried. Migration can also fail, in which case the pages will also have been unpinned but the operation should not be retried. If all pages are in the correct zone nothing will be unpinned and no retry is required. The logic in check_and_migrate_movable_pages() tracks unnecessary state and the return codes for each case are difficult to follow. Refactor the code to clean this up. No behaviour change is intended. [akpm@linux-foundation.org: fix unused var warning] Link: https://lkml.kernel.org/r/19583d1df07fdcb99cfa05c265588a3fa58d1902.1661317396.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Alex Sierra <alex.sierra@amd.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Felix Kuehling <felix.kuehling@amd.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Shigeru Yoshida <syoshida@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Alistair Popple
|
f6d299ec39 |
mm/gup.c: don't pass gup_flags to check_and_migrate_movable_pages()
gup_flags is passed to check_and_migrate_movable_pages() so that it can call either put_page() or unpin_user_page() to drop the page reference. However check_and_migrate_movable_pages() is only called for FOLL_LONGTERM, which implies FOLL_PIN so there is no need to pass gup_flags. Link: https://lkml.kernel.org/r/d611c65a9008ff55887307df457c6c2220ad6163.1661317396.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Alex Sierra <alex.sierra@amd.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Felix Kuehling <felix.kuehling@amd.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Shigeru Yoshida <syoshida@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Alistair Popple
|
24a95998e9 |
mm/gup.c: simplify and fix check_and_migrate_movable_pages() return codes
When pinning pages with FOLL_LONGTERM check_and_migrate_movable_pages() is called to migrate pages out of zones which should not contain any longterm pinned pages. When migration succeeds all pages will have been unpinned so pinning needs to be retried. This is indicated by returning zero. When all pages are in the correct zone the number of pinned pages is returned. However migration can also fail, in which case pages are unpinned and -ENOMEM is returned. However if the failure was due to not being unable to isolate a page zero is returned. This leads to indefinite looping in __gup_longterm_locked(). Fix this by simplifying the return codes such that zero indicates all pages were successfully pinned in the correct zone while errors indicate either pages were migrated and pinning should be retried or that migration has failed and therefore the pinning operation should fail. [syoshida@redhat.com: fix return value for __gup_longterm_locked()] Link: https://lkml.kernel.org/r/20220821183547.950370-1-syoshida@redhat.com [akpm@linux-foundation.org: fix code layout, per John] [yshigeru@gmail.com: fix uninitialized return value on __gup_longterm_locked()] Link: https://lkml.kernel.org/r/20220827230037.78876-1-syoshida@redhat.com Link: https://lkml.kernel.org/r/20220729024645.764366-1-apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
David Hildenbrand
|
5535be3099 |
mm/gup: fix FOLL_FORCE COW security issue and remove FOLL_COW
Ever since the Dirty COW (CVE-2016-5195) security issue happened, we know that FOLL_FORCE can be possibly dangerous, especially if there are races that can be exploited by user space. Right now, it would be sufficient to have some code that sets a PTE of a R/O-mapped shared page dirty, in order for it to erroneously become writable by FOLL_FORCE. The implications of setting a write-protected PTE dirty might not be immediately obvious to everyone. And in fact ever since commit |
||
|
Linus Torvalds
|
6614a3c316 |
- The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
- Some kmemleak fixes from Patrick Wang and Waiman Long
- DAMON updates from SeongJae Park
- memcg debug/visibility work from Roman Gushchin
- vmalloc speedup from Uladzislau Rezki
- more folio conversion work from Matthew Wilcox
- enhancements for coherent device memory mapping from Alex Sierra
- addition of shared pages tracking and CoW support for fsdax, from
Shiyang Ruan
- hugetlb optimizations from Mike Kravetz
- Mel Gorman has contributed some pagealloc changes to improve latency
and realtime behaviour.
- mprotect soft-dirty checking has been improved by Peter Xu
- Many other singleton patches all over the place
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCYuravgAKCRDdBJ7gKXxA
jpqSAQDrXSdII+ht9kSHlaCVYjqRFQz/rRvURQrWQV74f6aeiAD+NHHeDPwZn11/
SPktqEUrF1pxnGQxqLh1kUFUhsVZQgE=
=w/UH
-----END PGP SIGNATURE-----
Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Most of the MM queue. A few things are still pending.
Liam's maple tree rework didn't make it. This has resulted in a few
other minor patch series being held over for next time.
Multi-gen LRU still isn't merged as we were waiting for mapletree to
stabilize. The current plan is to merge MGLRU into -mm soon and to
later reintroduce mapletree, with a view to hopefully getting both
into 6.1-rc1.
Summary:
- The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
- Some kmemleak fixes from Patrick Wang and Waiman Long
- DAMON updates from SeongJae Park
- memcg debug/visibility work from Roman Gushchin
- vmalloc speedup from Uladzislau Rezki
- more folio conversion work from Matthew Wilcox
- enhancements for coherent device memory mapping from Alex Sierra
- addition of shared pages tracking and CoW support for fsdax, from
Shiyang Ruan
- hugetlb optimizations from Mike Kravetz
- Mel Gorman has contributed some pagealloc changes to improve
latency and realtime behaviour.
- mprotect soft-dirty checking has been improved by Peter Xu
- Many other singleton patches all over the place"
[ XFS merge from hell as per Darrick Wong in
https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ]
* tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits)
tools/testing/selftests/vm/hmm-tests.c: fix build
mm: Kconfig: fix typo
mm: memory-failure: convert to pr_fmt()
mm: use is_zone_movable_page() helper
hugetlbfs: fix inaccurate comment in hugetlbfs_statfs()
hugetlbfs: cleanup some comments in inode.c
hugetlbfs: remove unneeded header file
hugetlbfs: remove unneeded hugetlbfs_ops forward declaration
hugetlbfs: use helper macro SZ_1{K,M}
mm: cleanup is_highmem()
mm/hmm: add a test for cross device private faults
selftests: add soft-dirty into run_vmtests.sh
selftests: soft-dirty: add test for mprotect
mm/mprotect: fix soft-dirty check in can_change_pte_writable()
mm: memcontrol: fix potential oom_lock recursion deadlock
mm/gup.c: fix formatting in check_and_migrate_movable_page()
xfs: fail dax mount if reflink is enabled on a partition
mm/memcontrol.c: remove the redundant updating of stats_flush_threshold
userfaultfd: don't fail on unrecognized features
hugetlb_cgroup: fix wrong hugetlb cgroup numa stat
...
|
||
|
Alistair Popple
|
65974cb910 |
mm/gup.c: fix formatting in check_and_migrate_movable_page()
Commit
|
||
Muchun Song
|
f4f451a16d |
mm: fix missing wake-up event for FSDAX pages
FSDAX page refcounts are 1-based, rather than 0-based: if refcount is
1, then the page is freed. The FSDAX pages can be pinned through GUP,
then they will be unpinned via unpin_user_page() using a folio variant
to put the page, however, folio variants did not consider this special
case, the result will be to miss a wakeup event (like the user of
__fuse_dax_break_layouts()). This results in a task being permanently
stuck in TASK_INTERRUPTIBLE state.
Since FSDAX pages are only possibly obtained by GUP users, so fix GUP
instead of folio_put() to lower overhead.
Link: https://lkml.kernel.org/r/20220705123532.283-1-songmuchun@bytedance.com
Fixes:
|
||
Linus Walleij
|
396a400bc1 |
mm: gup: pass a pointer to virt_to_page()
Functions that work on a pointer to virtual memory such as virt_to_pfn()
and users of that function such as virt_to_page() are supposed to pass a
pointer to virtual memory, ideally a (void *) or other pointer. However
since many architectures implement virt_to_pfn() as a macro, this function
becomes polymorphic and accepts both a (unsigned long) and a (void *).
If we instead implement a proper virt_to_pfn(void *addr) function the
following happens (occurred on arch/arm):
mm/gup.c: In function '__get_user_pages_locked':
mm/gup.c:1599:49: warning: passing argument 1 of 'virt_to_pfn'
makes pointer from integer without a cast [-Wint-conversion]
pages[i] = virt_to_page(start);
Fix this with an explicit cast.
Link: https://lkml.kernel.org/r/20220630084124.691207-5-linus.walleij@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
|
Alistair Popple
|
b05a79d437 |
mm/gup: migrate device coherent pages when pinning instead of failing
Currently any attempts to pin a device coherent page will fail. This is because device coherent pages need to be managed by a device driver, and pinning them would prevent a driver from migrating them off the device. However this is no reason to fail pinning of these pages. These are coherent and accessible from the CPU so can be migrated just like pinning ZONE_MOVABLE pages. So instead of failing all attempts to pin them first try migrating them out of ZONE_DEVICE. [hch@lst.de: rebased to the split device memory checks, moved migrate_device_page to migrate_device.c] Link: https://lkml.kernel.org/r/20220715150521.18165-7-alex.sierra@amd.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Felix Kuehling <Felix.Kuehling@amd.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ralph Campbell <rcampbell@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Alex Sierra
|
6077c943be |
mm: rename is_pinnable_page() to is_longterm_pinnable_page()
Patch series "Add MEMORY_DEVICE_COHERENT for coherent device memory mapping", v9. This patch series introduces MEMORY_DEVICE_COHERENT, a type of memory owned by a device that can be mapped into CPU page tables like MEMORY_DEVICE_GENERIC and can also be migrated like MEMORY_DEVICE_PRIVATE. This patch series is mostly self-contained except for a few places where it needs to update other subsystems to handle the new memory type. System stability and performance are not affected according to our ongoing testing, including xfstests. How it works: The system BIOS advertises the GPU device memory (aka VRAM) as SPM (special purpose memory) in the UEFI system address map. The amdgpu driver registers the memory with devmap as MEMORY_DEVICE_COHERENT using devm_memremap_pages. The initial user for this hardware page migration capability is the Frontier supercomputer project. This functionality is not AMD-specific. We expect other GPU vendors to find this functionality useful, and possibly other hardware types in the future. Our test nodes in the lab are similar to the Frontier configuration, with .5 TB of system memory plus 256 GB of device memory split across 4 GPUs, all in a single coherent address space. Page migration is expected to improve application efficiency significantly. We will report empirical results as they become available. Coherent device type pages at gup are now migrated back to system memory if they are being pinned long-term (FOLL_LONGTERM). The reason is, that long-term pinning would interfere with the device memory manager owning the device-coherent pages (e.g. evictions in TTM). These series incorporate Alistair Popple patches to do this migration from pin_user_pages() calls. hmm_gup_test has been added to hmm-test to test different get user pages calls. This series includes handling of device-managed anonymous pages returned by vm_normal_pages. Although they behave like normal pages for purposes of mapping in CPU page tables and for COW, they do not support LRU lists, NUMA migration or THP. We also introduced a FOLL_LRU flag that adds the same behaviour to follow_page and related APIs, to allow callers to specify that they expect to put pages on an LRU list. This patch (of 14): is_pinnable_page() and folio_is_pinnable() are renamed to is_longterm_pinnable_page() and folio_is_longterm_pinnable() respectively. These functions are used in the FOLL_LONGTERM flag context. Link: https://lkml.kernel.org/r/20220715150521.18165-1-alex.sierra@amd.com Link: https://lkml.kernel.org/r/20220715150521.18165-2-alex.sierra@amd.com Signed-off-by: Alex Sierra <alex.sierra@amd.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Felix Kuehling <Felix.Kuehling@amd.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Miaohe Lin
|
7ce82f4c3f |
mm/migration: return errno when isolate_huge_page failed
We might fail to isolate huge page due to e.g. the page is under
migration which cleared HPageMigratable. We should return errno in this
case rather than always return 1 which could confuse the user, i.e. the
caller might think all of the memory is migrated while the hugetlb page is
left behind. We make the prototype of isolate_huge_page consistent with
isolate_lru_page as suggested by Huang Ying and rename isolate_huge_page
to isolate_hugetlb as suggested by Muchun to improve the readability.
Link: https://lkml.kernel.org/r/20220530113016.16663-4-linmiaohe@huawei.com
Fixes:
|
||
|
Peter Xu
|
d92725256b |
mm: avoid unnecessary page fault retires on shared memory types
I observed that for each of the shared file-backed page faults, we're very likely to retry one more time for the 1st write fault upon no page. It's because we'll need to release the mmap lock for dirty rate limit purpose with balance_dirty_pages_ratelimited() (in fault_dirty_shared_page()). Then after that throttling we return VM_FAULT_RETRY. We did that probably because VM_FAULT_RETRY is the only way we can return to the fault handler at that time telling it we've released the mmap lock. However that's not ideal because it's very likely the fault does not need to be retried at all since the pgtable was well installed before the throttling, so the next continuous fault (including taking mmap read lock, walk the pgtable, etc.) could be in most cases unnecessary. It's not only slowing down page faults for shared file-backed, but also add more mmap lock contention which is in most cases not needed at all. To observe this, one could try to write to some shmem page and look at "pgfault" value in /proc/vmstat, then we should expect 2 counts for each shmem write simply because we retried, and vm event "pgfault" will capture that. To make it more efficient, add a new VM_FAULT_COMPLETED return code just to show that we've completed the whole fault and released the lock. It's also a hint that we should very possibly not need another fault immediately on this page because we've just completed it. This patch provides a ~12% perf boost on my aarch64 test VM with a simple program sequentially dirtying 400MB shmem file being mmap()ed and these are the time it needs: Before: 650.980 ms (+-1.94%) After: 569.396 ms (+-1.38%) I believe it could help more than that. We need some special care on GUP and the s390 pgfault handler (for gmap code before returning from pgfault), the rest changes in the page fault handlers should be relatively straightforward. Another thing to mention is that mm_account_fault() does take this new fault as a generic fault to be accounted, unlike VM_FAULT_RETRY. I explicitly didn't touch hmm_vma_fault() and break_ksm() because they do not handle VM_FAULT_RETRY even with existing code, so I'm literally keeping them as-is. Link: https://lkml.kernel.org/r/20220530183450.42886-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vineet Gupta <vgupta@kernel.org> Acked-by: Guo Ren <guoren@kernel.org> Acked-by: Max Filippov <jcmvbkbc@gmail.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> [arm part] Acked-by: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Stafford Horne <shorne@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Brian Cain <bcain@quicinc.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Richard Weinberger <richard@nod.at> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Will Deacon <will@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Simek <monstr@monstr.eu> Cc: Matt Turner <mattst88@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: David Hildenbrand <david@redhat.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Chris Zankel <chris@zankel.net> Cc: Hugh Dickins <hughd@google.com> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Rich Felker <dalias@libc.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Helge Deller <deller@gmx.de> Cc: Yoshinori Sato <ysato@users.osdn.me> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Linus Torvalds
|
98931dd95f |
Yang Shi has improved the behaviour of khugepaged collapsing of readonly
file-backed transparent hugepages.
Johannes Weiner has arranged for zswap memory use to be tracked and
managed on a per-cgroup basis.
Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for runtime
enablement of the recent huge page vmemmap optimization feature.
Baolin Wang contributes a series to fix some issues around hugetlb
pagetable invalidation.
Zhenwei Pi has fixed some interactions between hwpoisoned pages and
virtualization.
Tong Tiangen has enabled the use of the presently x86-only
page_table_check debugging feature on arm64 and riscv.
David Vernet has done some fixup work on the memcg selftests.
Peter Xu has taught userfaultfd to handle write protection faults against
shmem- and hugetlbfs-backed files.
More DAMON development from SeongJae Park - adding online tuning of the
feature and support for monitoring of fixed virtual address ranges. Also
easier discovery of which monitoring operations are available.
Nadav Amit has done some optimization of TLB flushing during mprotect().
Neil Brown continues to labor away at improving our swap-over-NFS support.
David Hildenbrand has some fixes to anon page COWing versus
get_user_pages().
Peng Liu fixed some errors in the core hugetlb code.
Joao Martins has reduced the amount of memory consumed by device-dax's
compound devmaps.
Some cleanups of the arch-specific pagemap code from Anshuman Khandual.
Muchun Song has found and fixed some errors in the TLB flushing of
transparent hugepages.
Roman Gushchin has done more work on the memcg selftests.
And, of course, many smaller fixes and cleanups. Notably, the customary
million cleanup serieses from Miaohe Lin.
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCYo52xQAKCRDdBJ7gKXxA
jtJFAQD238KoeI9z5SkPMaeBRYSRQmNll85mxs25KapcEgWgGQD9FAb7DJkqsIVk
PzE+d9hEfirUGdL6cujatwJ6ejYR8Q8=
=nFe6
-----END PGP SIGNATURE-----
Merge tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Almost all of MM here. A few things are still getting finished off,
reviewed, etc.
- Yang Shi has improved the behaviour of khugepaged collapsing of
readonly file-backed transparent hugepages.
- Johannes Weiner has arranged for zswap memory use to be tracked and
managed on a per-cgroup basis.
- Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for
runtime enablement of the recent huge page vmemmap optimization
feature.
- Baolin Wang contributes a series to fix some issues around hugetlb
pagetable invalidation.
- Zhenwei Pi has fixed some interactions between hwpoisoned pages and
virtualization.
- Tong Tiangen has enabled the use of the presently x86-only
page_table_check debugging feature on arm64 and riscv.
- David Vernet has done some fixup work on the memcg selftests.
- Peter Xu has taught userfaultfd to handle write protection faults
against shmem- and hugetlbfs-backed files.
- More DAMON development from SeongJae Park - adding online tuning of
the feature and support for monitoring of fixed virtual address
ranges. Also easier discovery of which monitoring operations are
available.
- Nadav Amit has done some optimization of TLB flushing during
mprotect().
- Neil Brown continues to labor away at improving our swap-over-NFS
support.
- David Hildenbrand has some fixes to anon page COWing versus
get_user_pages().
- Peng Liu fixed some errors in the core hugetlb code.
- Joao Martins has reduced the amount of memory consumed by
device-dax's compound devmaps.
- Some cleanups of the arch-specific pagemap code from Anshuman
Khandual.
- Muchun Song has found and fixed some errors in the TLB flushing of
transparent hugepages.
- Roman Gushchin has done more work on the memcg selftests.
... and, of course, many smaller fixes and cleanups. Notably, the
customary million cleanup serieses from Miaohe Lin"
* tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (381 commits)
mm: kfence: use PAGE_ALIGNED helper
selftests: vm: add the "settings" file with timeout variable
selftests: vm: add "test_hmm.sh" to TEST_FILES
selftests: vm: check numa_available() before operating "merge_across_nodes" in ksm_tests
selftests: vm: add migration to the .gitignore
selftests/vm/pkeys: fix typo in comment
ksm: fix typo in comment
selftests: vm: add process_mrelease tests
Revert "mm/vmscan: never demote for memcg reclaim"
mm/kfence: print disabling or re-enabling message
include/trace/events/percpu.h: cleanup for "percpu: improve percpu_alloc_percpu event trace"
include/trace/events/mmflags.h: cleanup for "tracing: incorrect gfp_t conversion"
mm: fix a potential infinite loop in start_isolate_page_range()
MAINTAINERS: add Muchun as co-maintainer for HugeTLB
zram: fix Kconfig dependency warning
mm/shmem: fix shmem folio swapoff hang
cgroup: fix an error handling path in alloc_pagecache_max_30M()
mm: damon: use HPAGE_PMD_SIZE
tracing: incorrect isolate_mote_t cast in mm_vmscan_lru_isolate
nodemask.h: fix compilation error with GCC12
...
|
||
Yury Norov
|
0768c8de1b |
mm/gup: fix comments to pin_user_pages_*()
pin_user_pages API forces FOLL_PIN in gup_flags, which means that the API requires struct page **pages to be provided (not NULL). However, the comment to pin_user_pages() clearly allows for passing in a NULL @pages argument. Remove the incorrect comments, and add WARN_ON_ONCE(!pages) calls to enforce the API. It has been independently spotted by Minchan Kim and confirmed with John Hubbard: https://lore.kernel.org/all/YgWA0ghrrzHONehH@google.com/ Link: https://lkml.kernel.org/r/20220422015839.1274328-1-yury.norov@gmail.com Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
David Hildenbrand
|
b6a2619c60 |
mm/gup: sanity-check with CONFIG_DEBUG_VM that anonymous pages are exclusive when (un)pinning
Let's verify when (un)pinning anonymous pages that we always deal with exclusive anonymous pages, which guarantees that we'll have a reliable PIN, meaning that we cannot end up with the GUP pin being inconsistent with he pages mapped into the page tables due to a COW triggered by a write fault. When pinning pages, after conditionally triggering GUP unsharing of possibly shared anonymous pages, we should always only see exclusive anonymous pages. Note that anonymous pages that are mapped writable must be marked exclusive, otherwise we'd have a BUG. When pinning during ordinary GUP, simply add a check after our conditional GUP-triggered unsharing checks. As we know exactly how the page is mapped, we know exactly in which page we have to check for PageAnonExclusive(). When pinning via GUP-fast we have to be careful, because we can race with fork(): verify only after we made sure via the seqcount that we didn't race with concurrent fork() that we didn't end up pinning a possibly shared anonymous page. Similarly, when unpinning, verify that the pages are still marked as exclusive: otherwise something turned the pages possibly shared, which can result in random memory corruptions, which we really want to catch. With only the pinned pages at hand and not the actual page table entries we have to be a bit careful: hugetlb pages are always mapped via a single logical page table entry referencing the head page and PG_anon_exclusive of the head page applies. Anon THP are a bit more complicated, because we might have obtained the page reference either via a PMD or a PTE -- depending on the mapping type we either have to check PageAnonExclusive of the head page (PMD-mapped THP) or the tail page (PTE-mapped THP) applies: as we don't know and to make our life easier, check that either is set. Take care to not verify in case we're unpinning during GUP-fast because we detected concurrent fork(): we might stumble over an anonymous page that is now shared. Link: https://lkml.kernel.org/r/20220428083441.37290-18-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: David Rientjes <rientjes@google.com> Cc: Don Dutile <ddutile@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Liang Zhang <zhangliang5@huawei.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Nadav Amit <namit@vmware.com> Cc: Oded Gabbay <oded.gabbay@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pedro Demarchi Gomes <pedrodemargomes@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <guro@fb.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
David Hildenbrand
|
a7f2266041 |
mm/gup: trigger FAULT_FLAG_UNSHARE when R/O-pinning a possibly shared anonymous page
Whenever GUP currently ends up taking a R/O pin on an anonymous page that
might be shared -- mapped R/O and !PageAnonExclusive() -- any write fault
on the page table entry will end up replacing the mapped anonymous page
due to COW, resulting in the GUP pin no longer being consistent with the
page actually mapped into the page table.
The possible ways to deal with this situation are:
(1) Ignore and pin -- what we do right now.
(2) Fail to pin -- which would be rather surprising to callers and
could break user space.
(3) Trigger unsharing and pin the now exclusive page -- reliable R/O
pins.
Let's implement 3) because it provides the clearest semantics and allows
for checking in unpin_user_pages() and friends for possible BUGs: when
trying to unpin a page that's no longer exclusive, clearly something went
very wrong and might result in memory corruptions that might be hard to
debug. So we better have a nice way to spot such issues.
This change implies that whenever user space *wrote* to a private mapping
(IOW, we have an anonymous page mapped), that GUP pins will always remain
consistent: reliable R/O GUP pins of anonymous pages.
As a side note, this commit fixes the COW security issue for hugetlb with
FOLL_PIN as documented in:
https://lore.kernel.org/r/3ae33b08-d9ef-f846-56fb-645e3b9b4c66@redhat.com
The vmsplice reproducer still applies, because vmsplice uses FOLL_GET
instead of FOLL_PIN.
Note that follow_huge_pmd() doesn't apply because we cannot end up in
there with FOLL_PIN.
This commit is heavily based on prototype patches by Andrea.
Link: https://lkml.kernel.org/r/20220428083441.37290-17-david@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Co-developed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Don Dutile <ddutile@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Liang Zhang <zhangliang5@huawei.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Oded Gabbay <oded.gabbay@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pedro Demarchi Gomes <pedrodemargomes@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
|
David Hildenbrand
|
8909691b6c |
mm/gup: disallow follow_page(FOLL_PIN)
We want to change the way we handle R/O pins on anonymous pages that might be shared: if we detect a possibly shared anonymous page -- mapped R/O and not !PageAnonExclusive() -- we want to trigger unsharing via a page fault, resulting in an exclusive anonymous page that can be pinned reliably without getting replaced via COW on the next write fault. However, the required page fault will be problematic for follow_page(): in contrast to ordinary GUP, follow_page() doesn't trigger faults internally. So we would have to end up failing a R/O pin via follow_page(), although there is something mapped R/O into the page table, which might be rather surprising. We don't seem to have follow_page(FOLL_PIN) users, and it's a purely internal MM function. Let's just make our life easier and the semantics of follow_page() clearer by just disallowing FOLL_PIN for follow_page() completely. Link: https://lkml.kernel.org/r/20220428083441.37290-15-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: David Rientjes <rientjes@google.com> Cc: Don Dutile <ddutile@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Liang Zhang <zhangliang5@huawei.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Nadav Amit <namit@vmware.com> Cc: Oded Gabbay <oded.gabbay@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pedro Demarchi Gomes <pedrodemargomes@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <guro@fb.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Catalin Marinas
|
da32b58172 |
mm: Add fault_in_subpage_writeable() to probe at sub-page granularity
On hardware with features like arm64 MTE or SPARC ADI, an access fault can be triggered at sub-page granularity. Depending on how the fault_in_writeable() function is used, the caller can get into a live-lock by continuously retrying the fault-in on an address different from the one where the uaccess failed. In the majority of cases progress is ensured by the following conditions: 1. copy_to_user_nofault() guarantees at least one byte access if the user address is not faulting. 2. The fault_in_writeable() loop is resumed from the first address that could not be accessed by copy_to_user_nofault(). If the loop iteration is restarted from an earlier (initial) point, the loop is repeated with the same conditions and it would live-lock. Introduce an arch-specific probe_subpage_writeable() and call it from the newly added fault_in_subpage_writeable() function. The arch code with sub-page faults will have to implement the specific probing functionality. Note that no other fault_in_subpage_*() functions are added since they have no callers currently susceptible to a live-lock. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lore.kernel.org/r/20220423100751.1870771-2-catalin.marinas@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> |
||
Hugh Dickins
|
ece369c7e1 |
mm/munlock: add lru_add_drain() to fix memcg_stat_test
Mike reports that LTP memcg_stat_test usually leads to
memcg_stat_test 3 TINFO: Test unevictable with MAP_LOCKED
memcg_stat_test 3 TINFO: Running memcg_process --mmap-lock1 -s 135168
memcg_stat_test 3 TINFO: Warming up pid: 3460
memcg_stat_test 3 TINFO: Process is still here after warm up: 3460
memcg_stat_test 3 TFAIL: unevictable is 122880, 135168 expected
but may also lead to
memcg_stat_test 4 TINFO: Test unevictable with mlock
memcg_stat_test 4 TINFO: Running memcg_process --mmap-lock2 -s 135168
memcg_stat_test 4 TINFO: Warming up pid: 4271
memcg_stat_test 4 TINFO: Process is still here after warm up: 4271
memcg_stat_test 4 TFAIL: unevictable is 122880, 135168 expected
or both. A wee bit flaky.
follow_page_pte() used to have an lru_add_drain() per each page mlocked,
and the test came to rely on accurate stats. The pagevec to be drained
is different now, but still covered by lru_add_drain(); and, never mind
the test, I believe it's in everyone's interest that a bulk faulting
interface like populate_vma_page_range() or faultin_vma_page_range()
should drain its local pagevecs at the end, to save others sometimes
needing the much more expensive lru_add_drain_all().
This does not absolutely guarantee exact stats - the mlocking task can
be migrated between CPUs as it proceeds - but it's good enough and the
tests pass.
Link: https://lkml.kernel.org/r/47f6d39c-a075-50cb-1cfb-26dd957a48af@google.com
Fixes:
|
||
|
Linus Torvalds
|
9030fb0bb9 |
Folio changes for 5.18
- Rewrite how munlock works to massively reduce the contention
on i_mmap_rwsem (Hugh Dickins):
https://lore.kernel.org/linux-mm/8e4356d-9622-a7f0-b2c-f116b5f2efea@google.com/
- Sort out the page refcount mess for ZONE_DEVICE pages (Christoph Hellwig):
https://lore.kernel.org/linux-mm/20220210072828.2930359-1-hch@lst.de/
- Convert GUP to use folios and make pincount available for order-1
pages. (Matthew Wilcox)
- Convert a few more truncation functions to use folios (Matthew Wilcox)
- Convert page_vma_mapped_walk to use PFNs instead of pages (Matthew Wilcox)
- Convert rmap_walk to use folios (Matthew Wilcox)
- Convert most of shrink_page_list() to use a folio (Matthew Wilcox)
- Add support for creating large folios in readahead (Matthew Wilcox)
-----BEGIN PGP SIGNATURE-----
iQEzBAABCgAdFiEEejHryeLBw/spnjHrDpNsjXcpgj4FAmI4ucgACgkQDpNsjXcp
gj69Wgf6AwqwmO5Tmy+fLScDPqWxmXJofbocae1kyoGHf7Ui91OK4U2j6IpvAr+g
P/vLIK+JAAcTQcrSCjymuEkf4HkGZOR03QQn7maPIEe4eLrZRQDEsmHC1L9gpeJp
s/GMvDWiGE0Tnxu0EOzfVi/yT+qjIl/S8VvqtCoJv1HdzxitZ7+1RDuqImaMC5MM
Qi3uHag78vLmCltLXpIOdpgZhdZexCdL2Y/1npf+b6FVkAJRRNUnA0gRbS7YpoVp
CbxEJcmAl9cpJLuj5i5kIfS9trr+/QcvbUlzRxh4ggC58iqnmF2V09l2MJ7YU3XL
v1O/Elq4lRhXninZFQEm9zjrri7LDQ==
=n9Ad
-----END PGP SIGNATURE-----
Merge tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache
Pull folio updates from Matthew Wilcox:
- Rewrite how munlock works to massively reduce the contention on
i_mmap_rwsem (Hugh Dickins):
https://lore.kernel.org/linux-mm/8e4356d-9622-a7f0-b2c-f116b5f2efea@google.com/
- Sort out the page refcount mess for ZONE_DEVICE pages (Christoph
Hellwig):
https://lore.kernel.org/linux-mm/20220210072828.2930359-1-hch@lst.de/
- Convert GUP to use folios and make pincount available for order-1
pages. (Matthew Wilcox)
- Convert a few more truncation functions to use folios (Matthew
Wilcox)
- Convert page_vma_mapped_walk to use PFNs instead of pages (Matthew
Wilcox)
- Convert rmap_walk to use folios (Matthew Wilcox)
- Convert most of shrink_page_list() to use a folio (Matthew Wilcox)
- Add support for creating large folios in readahead (Matthew Wilcox)
* tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache: (114 commits)
mm/damon: minor cleanup for damon_pa_young
selftests/vm/transhuge-stress: Support file-backed PMD folios
mm/filemap: Support VM_HUGEPAGE for file mappings
mm/readahead: Switch to page_cache_ra_order
mm/readahead: Align file mappings for non-DAX
mm/readahead: Add large folio readahead
mm: Support arbitrary THP sizes
mm: Make large folios depend on THP
mm: Fix READ_ONLY_THP warning
mm/filemap: Allow large folios to be added to the page cache
mm: Turn can_split_huge_page() into can_split_folio()
mm/vmscan: Convert pageout() to take a folio
mm/vmscan: Turn page_check_references() into folio_check_references()
mm/vmscan: Account large folios correctly
mm/vmscan: Optimise shrink_page_list for non-PMD-sized folios
mm/vmscan: Free non-shmem folios without splitting them
mm/rmap: Constify the rmap_walk_control argument
mm/rmap: Convert rmap_walk() to take a folio
mm: Turn page_anon_vma() into folio_anon_vma()
mm/rmap: Turn page_lock_anon_vma_read() into folio_lock_anon_vma_read()
...
|
||
John Hubbard
|
73fd16d808 |
mm/gup: remove unused get_user_pages_locked()
Now that the last caller of get_user_pages_locked() is gone, remove it. Link: https://lkml.kernel.org/r/20220204020010.68930-6-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
John Hubbard
|
ad6c441266 |
mm/gup: remove unused pin_user_pages_locked()
This routine was used for a short while, but then the calling code was refactored and the only caller was removed. Link: https://lkml.kernel.org/r/20220204020010.68930-4-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
John Hubbard
|
65462462ff |
mm/gup: follow_pfn_pte(): -EEXIST cleanup
Remove a quirky special case from follow_pfn_pte(), and adjust its callers to match. Caller changes include: __get_user_pages(): Regardless of any FOLL_* flags, get_user_pages() and its variants should handle PFN-only entries by stopping early, if the caller expected **pages to be filled in. This makes for a more reliable API, as compared to the previous approach of skipping over such entries (and thus leaving them silently unwritten). move_pages(): squash the -EEXIST error return from follow_page() into -EFAULT, because -EFAULT is listed in the man page, whereas -EEXIST is not. Link: https://lkml.kernel.org/r/20220204020010.68930-3-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Peter Xu <peterx@redhat.com> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Peter Xu
|
7196040e19 |
mm: fix invalid page pointer returned with FOLL_PIN gups
Patch series "mm/gup: some cleanups", v5. This patch (of 5): Alex reported invalid page pointer returned with pin_user_pages_remote() from vfio after upstream commit |
||
Matthew Wilcox (Oracle)
|
1b7f7e58de |
mm/gup: Convert check_and_migrate_movable_pages() to use a folio
Switch from head pages to folios. This removes an assumption that THPs are the only way to have a high-order page. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
659508f9c9 |
mm/gup: Turn compound_range_next() into gup_folio_range_next()
Convert the only caller to work on folios instead of pages. This removes the last caller of put_compound_head(), so delete it. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
12521c7606 |
mm/gup: Turn compound_next() into gup_folio_next()
Convert both callers to work on folios instead of pages. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
2d7919a292 |
mm/gup: Convert gup_huge_pgd() to use a folio
Use the new folio-based APIs. This was the last user of try_grab_compound_head(), so remove it. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
83afb52e47 |
mm/gup: Convert gup_huge_pud() to use a folio
Use the new folio-based APIs. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
667ed1f7bb |
mm/gup: Convert gup_huge_pmd() to use a folio
Use the new folio-based APIs. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
09a1626eff |
mm/gup: Convert gup_hugepte() to use a folio
There should be little to no effect from this patch; just removing uses of some old APIs. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
b0496fe4ef |
mm/gup: Convert gup_pte_range() to use a folio
We still call try_grab_folio() once per PTE; a future patch could optimise to just adjust the reference count for each page within the folio. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
822951d846 |
mm/hugetlb: Use try_grab_folio() instead of try_grab_compound_head()
follow_hugetlb_page() only cares about success or failure, so it doesn't need to know the type of the returned pointer, only whether it's NULL or not. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
d8ddc099c6 |
mm/gup: Add gup_put_folio()
Convert put_compound_head() to gup_put_folio() and hpage_pincount_sub() to folio_pincount_sub(). This removes the last call to put_page_refs(), so delete it. Add a temporary put_compound_head() wrapper which will be deleted by the end of this series. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
5fec071990 |
mm/gup: Convert try_grab_page() to use a folio
Hoist the folio conversion and the folio_ref_count() check to the top of the function instead of using the one buried in try_get_page(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> |
||
|
Matthew Wilcox (Oracle)
|
ece1ed7bfa |
mm/gup: Add try_get_folio() and try_grab_folio()
Convert try_get_compound_head() into try_get_folio() and convert try_grab_compound_head() into try_grab_folio(). Add a temporary try_grab_compound_head() wrapper around try_grab_folio() to let us convert callers individually. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
5232c63f46 |
mm: Make compound_pincount always available
Move compound_pincount from the third page to the second page, which means it's available for all compound pages. That lets us delete hpage_pincount_available(). On 32-bit systems, there isn't enough space for both compound_pincount and compound_nr in the second page (it would collide with page->private, which is in use for pages in the swap cache), so revert the optimisation of storing both compound_order and compound_nr on 32-bit systems. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
6315d8a23c |
mm/gup: Remove hpage_pincount_sub()
Move the assertion (and correct it to be a cheaper variant), and inline the atomic_sub() operation. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
78d9d6ced3 |
mm/gup: Remove hpage_pincount_add()
It's clearer to call atomic_add() in the callers; the assertions clearly can't fire there because they're part of the condition for calling atomic_add(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> |
||
|
Matthew Wilcox (Oracle)
|
59409373f6 |
mm/gup: Handle page split race more efficiently
If we hit the page split race, the current code returns NULL which will presumably trigger a retry under the mmap_lock. This isn't necessary; we can just retry the compound_head() lookup. This is a very minor optimisation of an unlikely path, but conceptually it matches (eg) the page cache RCU-protected lookup. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
4c65422901 |
mm/gup: Remove an assumption of a contiguous memmap
This assumption needs the inverse of nth_page(), which is temporarily named page_nth() until it's renamed later in this series. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
c228afb11a |
mm/gup: Fix some contiguous memmap assumptions
Several functions in gup.c assume that a compound page has virtually contiguous page structs. This isn't true for SPARSEMEM configs unless SPARSEMEM_VMEMMAP is also set. Fix them by using nth_page() instead of plain pointer arithmetic. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
28297dbcad |
mm/gup: Change the calling convention for compound_next()
Return the head page instead of storing it to a passed parameter. Reorder the arguments to match the calling function's arguments. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
0b046e12ae |
mm/gup: Optimise compound_range_next()
By definition, a compound page has an order >= 1, so the second half of the test was redundant. Also, this cannot be a tail page since it's the result of calling compound_head(), so use PageHead() instead of PageCompound(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
8f39f5fcb7 |
mm/gup: Change the calling convention for compound_range_next()
Return the head page instead of storing it to a passed parameter. Pass the start page directly instead of passing a pointer to it. Reorder the arguments to match the calling function's arguments. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> |
||
|
Matthew Wilcox (Oracle)
|
e760274886 |
mm/gup: Remove for_each_compound_head()
This macro doesn't simplify the users; it's easier to just call compound_next() inside a standard loop. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
a5f100db68 |
mm/gup: Remove for_each_compound_range()
This macro doesn't simplify the users; it's easier to just call compound_range_next() inside the loop. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> |
||
|
Matthew Wilcox (Oracle)
|
8ea2979c14 |
mm/gup: Increment the page refcount before the pincount
We should always increase the refcount before doing anything else to the page so that other page users see the elevated refcount first. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> |
||
|
Linus Torvalds
|
fe673d3f5b |
mm: gup: make fault_in_safe_writeable() use fixup_user_fault()
Instead of using GUP, make fault_in_safe_writeable() actually force a
'handle_mm_fault()' using the same fixup_user_fault() machinery that
futexes already use.
Using the GUP machinery meant that fault_in_safe_writeable() did not do
everything that a real fault would do, ranging from not auto-expanding
the stack segment, to not updating accessed or dirty flags in the page
tables (GUP sets those flags on the pages themselves).
The latter causes problems on architectures (like s390) that do accessed
bit handling in software, which meant that fault_in_safe_writeable()
didn't actually do all the fault handling it needed to, and trying to
access the user address afterwards would still cause faults.
Reported-and-tested-by: Andreas Gruenbacher <agruenba@redhat.com>
Fixes:
|
||
Christoph Hellwig
|
f9f38f78c5 |
mm: refactor check_and_migrate_movable_pages
Remove up to two levels of indentation by using continue statements and move variables to local scope where possible. Link: https://lkml.kernel.org/r/20220210072828.2930359-11-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: "Sierra Guiza, Alejandro (Alex)" <alex.sierra@amd.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Chaitanya Kulkarni <kch@nvidia.com> Cc: Christian Knig <christian.koenig@amd.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Felix Kuehling <Felix.Kuehling@amd.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Karol Herbst <kherbst@redhat.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Lyude Paul <lyude@redhat.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> |
||
|
Hugh Dickins
|
b67bf49ce7 |
mm/munlock: delete FOLL_MLOCK and FOLL_POPULATE
If counting page mlocks, we must not double-count: follow_page_pte() can tell if a page has already been Mlocked or not, but cannot tell if a pte has already been counted or not: that will have to be done when the pte is mapped in (which lru_cache_add_inactive_or_unevictable() already tracks for new anon pages, but there's no such tracking yet for others). Delete all the FOLL_MLOCK code - faulting in the missing pages will do all that is necessary, without special mlock_vma_page() calls from here. But then FOLL_POPULATE turns out to serve no purpose - it was there so that its absence would tell faultin_page() not to faultin page when setting up VM_LOCKONFAULT areas; but if there's no special work needed here for mlock, then there's no work at all here for VM_LOCKONFAULT. Have I got that right? I've not looked into the history, but see that FOLL_POPULATE goes back before VM_LOCKONFAULT: did it serve a different purpose before? Ah, yes, it was used to skip the old stack guard page. And is it intentional that COW is not broken on existing pages when setting up a VM_LOCKONFAULT area? I can see that being argued either way, and have no reason to disagree with current behaviour. Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> |
||
|
John Hubbard
|
c36c04c2e1 |
Revert "mm/gup: small refactoring: simplify try_grab_page()"
This reverts commit |
||
Li Xinhai
|
28b0ee3fb3 |
mm/gup.c: stricter check on THP migration entry during follow_pmd_mask
When BUG_ON check for THP migration entry, the existing code only check thp_migration_supported case, but not for !thp_migration_supported case. If !thp_migration_supported() and !pmd_present(), the original code may dead loop in theory. To make the BUG_ON check consistent, we need catch both cases. Move the BUG_ON check one step earlier, because if the bug happen we should know it instead of depend on FOLL_MIGRATION been used by caller. Because pmdval instead of *pmd is read by the is_pmd_migration_entry() check, the existing code don't help to avoid useless locking within pmd_migration_entry_wait(), so remove that check. Link: https://lkml.kernel.org/r/20211217062559.737063-1-lixinhai.lxh@gmail.com Signed-off-by: Li Xinhai <lixinhai.lxh@gmail.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Zi Yan <ziy@nvidia.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Christophe Leroy
|
677b2a8c1f |
gup: avoid multiple user access locking/unlocking in fault_in_{read/write}able
fault_in_readable() and fault_in_writeable() perform __get_user() and __put_user() in a loop, implying multiple user access locking/unlocking. To avoid that, use user access blocks. Link: https://lkml.kernel.org/r/720dcf79314acca1a78fae56d478cc851952149d.1637084492.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Linus Torvalds
|
512b7931ad |
Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton: "257 patches. Subsystems affected by this patch series: scripts, ocfs2, vfs, and mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache, gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools, memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm, vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram, cleanups, kfence, and damon)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (257 commits) mm/damon: remove return value from before_terminate callback mm/damon: fix a few spelling mistakes in comments and a pr_debug message mm/damon: simplify stop mechanism Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions Docs/admin-guide/mm/damon/start: simplify the content Docs/admin-guide/mm/damon/start: fix a wrong link Docs/admin-guide/mm/damon/start: fix wrong example commands mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on mm/damon: remove unnecessary variable initialization Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM) selftests/damon: support watermarks mm/damon/dbgfs: support watermarks mm/damon/schemes: activate schemes based on a watermarks mechanism tools/selftests/damon: update for regions prioritization of schemes mm/damon/dbgfs: support prioritization weights mm/damon/vaddr,paddr: support pageout prioritization mm/damon/schemes: prioritize regions within the quotas mm/damon/selftests: support schemes quotas mm/damon/dbgfs: support quotas of schemes ... |
||
|
John Hubbard
|
20b7fee738 |
mm/gup: further simplify __gup_device_huge()
Commit
|
||
Andreas Gruenbacher
|
55b8fe703b |
gup: Introduce FOLL_NOFAULT flag to disable page faults
Introduce a new FOLL_NOFAULT flag that causes get_user_pages to return -EFAULT when it would otherwise trigger a page fault. This is roughly similar to FOLL_FAST_ONLY but available on all architectures, and less fragile. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> |
||
|
Andreas Gruenbacher
|
cdd591fc86 |
iov_iter: Introduce fault_in_iov_iter_writeable
Introduce a new fault_in_iov_iter_writeable helper for safely faulting in an iterator for writing. Uses get_user_pages() to fault in the pages without actually writing to them, which would be destructive. We'll use fault_in_iov_iter_writeable in gfs2 once we've determined that the iterator passed to .read_iter isn't in memory. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> |
||
|
Andreas Gruenbacher
|
bb523b406c |
gup: Turn fault_in_pages_{readable,writeable} into fault_in_{readable,writeable}
Turn fault_in_pages_{readable,writeable} into versions that return the
number of bytes not faulted in, similar to copy_to_user, instead of
returning a non-zero value when any of the requested pages couldn't be
faulted in. This supports the existing users that require all pages to
be faulted in as well as new users that are happy if any pages can be
faulted in.
Rename the functions to fault_in_{readable,writeable} to make sure
this change doesn't silently break things.
Neither of these functions is entirely trivial and it doesn't seem
useful to inline them, so move them to mm/gup.c.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
|
||
|
Linus Torvalds
|
cd1adf1b63 |
Revert "mm/gup: remove try_get_page(), call try_get_compound_head() directly"
This reverts commit
|
||
Yang Shi
|
5ac95884a7 |
mm/migrate: enable returning precise migrate_pages() success count
Under normal circumstances, migrate_pages() returns the number of pages migrated. In error conditions, it returns an error code. When returning an error code, there is no way to know how many pages were migrated or not migrated. Make migrate_pages() return how many pages are demoted successfully for all cases, including when encountering errors. Page reclaim behavior will depend on this in subsequent patches. Link: https://lkml.kernel.org/r/20210721063926.3024591-3-ying.huang@intel.com Link: https://lkml.kernel.org/r/20210715055145.195411-4-ying.huang@intel.com Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Suggested-by: Oscar Salvador <osalvador@suse.de> [optional parameter] Reviewed-by: Yang Shi <shy828301@gmail.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Wei Xu <weixugc@google.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Keith Busch <kbusch@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
John Hubbard
|
9857a17f20 |
mm/gup: remove try_get_page(), call try_get_compound_head() directly
try_get_page() is very similar to try_get_compound_head(), and in fact try_get_page() has fallen a little behind in terms of maintenance: try_get_compound_head() handles speculative page references more thoroughly. There are only two try_get_page() callsites, so just call try_get_compound_head() directly from those, and remove try_get_page() entirely. Also, seeing as how this changes try_get_compound_head() into a non-static function, provide some kerneldoc documentation for it. Link: https://lkml.kernel.org/r/20210813044133.1536842-4-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
John Hubbard
|
54d516b1d6 |
mm/gup: small refactoring: simplify try_grab_page()
try_grab_page() does the same thing as try_grab_compound_head(..., refs=1, ...), just with a different API. So there is a lot of code duplication there. Change try_grab_page() to call try_grab_compound_head(), while keeping the API contract identical for callers. Also, now that try_grab_compound_head() always has a caller, remove the __maybe_unused annotation. Link: https://lkml.kernel.org/r/20210813044133.1536842-3-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
John Hubbard
|
3967db22ba |
mm/gup: documentation corrections for gup/pup
Patch series "A few gup refactorings and documentation updates", v3. While reviewing some of the other things going on around gup.c, I noticed that the documentation was wrong for a few of the routines that I wrote. And then I noticed that there was some significant code duplication too. So this fixes those issues. This is not entirely risk-free, but after looking closely at this, I think it's actually a useful improvement, getting rid of the code duplication here. This patch (of 3): The documentation for try_grab_compound_head() and try_grab_page() has fallen a little out of date. Update and clarify a few points. Also make it kerneldoc-correct, by adding @args documentation. Link: https://lkml.kernel.org/r/20210813044133.1536842-1-jhubbard@nvidia.com Link: https://lkml.kernel.org/r/20210813044133.1536842-2-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Miaohe Lin
|
be51eb18b8 |
mm: gup: use helper PAGE_ALIGNED in populate_vma_page_range()
Use helper PAGE_ALIGNED to check if address is aligned to PAGE_SIZE. Minor readability improvement. Link: https://lkml.kernel.org/r/20210807093620.21347-6-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Miaohe Lin
|
6401c4eb57 |
mm: gup: fix potential pgmap refcnt leak in __gup_device_huge()
When failed to try_grab_page, put_dev_pagemap() is missed. So pgmap
refcnt will leak in this case. Also we remove the check for pgmap against
NULL as it's also checked inside the put_dev_pagemap().
[akpm@linux-foundation.org: simplify, cleanup]
[akpm@linux-foundation.org: fix return value]
Link: https://lkml.kernel.org/r/20210807093620.21347-5-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Fixes:
|
||
|
Miaohe Lin
|
06a9e69663 |
mm: gup: remove useless BUG_ON in __get_user_pages()
Indeed, this BUG_ON couldn't catch anything useful. We are sure ret == 0 here because we would already bail out if ret != 0 and ret is untouched till here. Link: https://lkml.kernel.org/r/20210807093620.21347-4-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Miaohe Lin
|
0fef147ba7 |
mm: gup: remove unneed local variable orig_refs
Remove unneed local variable orig_refs since refs is unchanged now. Link: https://lkml.kernel.org/r/20210807093620.21347-3-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Miaohe Lin
|
8fed2f3cd6 |
mm: gup: remove set but unused local variable major
Patch series "Cleanups and fixup for gup".
This series contains cleanups to remove unneeded variable, useless BUG_ON
and use helper to improve readability. Also we fix a potential pgmap
refcnt leak. More details can be found in the respective changelogs.
This patch (of 5):
Since commit
|
||
|
David Hildenbrand
|
eb2faa513c |
mm/madvise: report SIGBUS as -EFAULT for MADV_POPULATE_(READ|WRITE)
Doing some extended tests and polishing the man page update for
MADV_POPULATE_(READ|WRITE), I realized that we end up converting also
SIGBUS (via -EFAULT) to -EINVAL, making it look like yet another
madvise() user error.
We want to report only problematic mappings and permission problems that
the user could have know as -EINVAL.
Let's not convert -EFAULT arising due to SIGBUS (or SIGSEGV) to -EINVAL,
but instead indicate -EFAULT to user space. While we could also convert
it to -ENOMEM, using -EFAULT looks more helpful when user space might
want to troubleshoot what's going wrong: MADV_POPULATE_(READ|WRITE) is
not part of an final Linux release and we can still adjust the behavior.
Link: https://lkml.kernel.org/r/20210726154932.102880-1-david@redhat.com
Fixes:
|
||
Mike Rapoport
|
1507f51255 |
mm: introduce memfd_secret system call to create "secret" memory areas
Introduce "memfd_secret" system call with the ability to create memory
areas visible only in the context of the owning process and not mapped not
only to other processes but in the kernel page tables as well.
The secretmem feature is off by default and the user must explicitly
enable it at the boot time.
Once secretmem is enabled, the user will be able to create a file
descriptor using the memfd_secret() system call. The memory areas created
by mmap() calls from this file descriptor will be unmapped from the kernel
direct map and they will be only mapped in the page table of the processes
that have access to the file descriptor.
Secretmem is designed to provide the following protections:
* Enhanced protection (in conjunction with all the other in-kernel
attack prevention systems) against ROP attacks. Seceretmem makes
"simple" ROP insufficient to perform exfiltration, which increases the
required complexity of the attack. Along with other protections like
the kernel stack size limit and address space layout randomization which
make finding gadgets is really hard, absence of any in-kernel primitive
for accessing secret memory means the one gadget ROP attack can't work.
Since the only way to access secret memory is to reconstruct the missing
mapping entry, the attacker has to recover the physical page and insert
a PTE pointing to it in the kernel and then retrieve the contents. That
takes at least three gadgets which is a level of difficulty beyond most
standard attacks.
* Prevent cross-process secret userspace memory exposures. Once the
secret memory is allocated, the user can't accidentally pass it into the
kernel to be transmitted somewhere. The secreremem pages cannot be
accessed via the direct map and they are disallowed in GUP.
* Harden against exploited kernel flaws. In order to access secretmem,
a kernel-side attack would need to either walk the page tables and
create new ones, or spawn a new privileged uiserspace process to perform
secrets exfiltration using ptrace.
The file descriptor based memory has several advantages over the
"traditional" mm interfaces, such as mlock(), mprotect(), madvise(). File
descriptor approach allows explicit and controlled sharing of the memory
areas, it allows to seal the operations. Besides, file descriptor based
memory paves the way for VMMs to remove the secret memory range from the
userspace hipervisor process, for instance QEMU. Andy Lutomirski says:
"Getting fd-backed memory into a guest will take some possibly major
work in the kernel, but getting vma-backed memory into a guest without
mapping it in the host user address space seems much, much worse."
memfd_secret() is made a dedicated system call rather than an extension to
memfd_create() because it's purpose is to allow the user to create more
secure memory mappings rather than to simply allow file based access to
the memory. Nowadays a new system call cost is negligible while it is way
simpler for userspace to deal with a clear-cut system calls than with a
multiplexer or an overloaded syscall. Moreover, the initial
implementation of memfd_secret() is completely distinct from
memfd_create() so there is no much sense in overloading memfd_create() to
begin with. If there will be a need for code sharing between these
implementation it can be easily achieved without a need to adjust user
visible APIs.
The secret memory remains accessible in the process context using uaccess
primitives, but it is not exposed to the kernel otherwise; secret memory
areas are removed from the direct map and functions in the
follow_page()/get_user_page() family will refuse to return a page that
belongs to the secret memory area.
Once there will be a use case that will require exposing secretmem to the
kernel it will be an opt-in request in the system call flags so that user
would have to decide what data can be exposed to the kernel.
Removing of the pages from the direct map may cause its fragmentation on
architectures that use large pages to map the physical memory which
affects the system performance. However, the original Kconfig text for
CONFIG_DIRECT_GBPAGES said that gigabyte pages in the direct map "... can
improve the kernel's performance a tiny bit ..." (commit
|
||
|
David Hildenbrand
|
4ca9b3859d |
mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page tables
I. Background: Sparse Memory Mappings When we manage sparse memory mappings dynamically in user space - also sometimes involving MAP_NORESERVE - we want to dynamically populate/ discard memory inside such a sparse memory region. Example users are hypervisors (especially implementing memory ballooning or similar technologies like virtio-mem) and memory allocators. In addition, we want to fail in a nice way (instead of generating SIGBUS) if populating does not succeed because we are out of backend memory (which can happen easily with file-based mappings, especially tmpfs and hugetlbfs). While MADV_DONTNEED, MADV_REMOVE and FALLOC_FL_PUNCH_HOLE allow for reliably discarding memory for most mapping types, there is no generic approach to populate page tables and preallocate memory. Although mmap() supports MAP_POPULATE, it is not applicable to the concept of sparse memory mappings, where we want to populate/discard dynamically and avoid expensive/problematic remappings. In addition, we never actually report errors during the final populate phase - it is best-effort only. fallocate() can be used to preallocate file-based memory and fail in a safe way. However, it cannot really be used for any private mappings on anonymous files via memfd due to COW semantics. In addition, fallocate() does not actually populate page tables, so we still always get pagefaults on first access - which is sometimes undesired (i.e., real-time workloads) and requires real prefaulting of page tables, not just a preallocation of backend storage. There might be interesting use cases for sparse memory regions along with mlockall(MCL_ONFAULT) which fallocate() cannot satisfy as it does not prefault page tables. II. On preallcoation/prefaulting from user space Because we don't have a proper interface, what applications (like QEMU and databases) end up doing is touching (i.e., reading+writing one byte to not overwrite existing data) all individual pages. However, that approach 1) Can result in wear on storage backing, because we end up reading/writing each page; this is especially a problem for dax/pmem. 2) Can result in mmap_sem contention when prefaulting via multiple threads. 3) Requires expensive signal handling, especially to catch SIGBUS in case of hugetlbfs/shmem/file-backed memory. For example, this is problematic in hypervisors like QEMU where SIGBUS handlers might already be used by other subsystems concurrently to e.g, handle hardware errors. "Simply" doing preallocation concurrently from other thread is not that easy. III. On MADV_WILLNEED Extending MADV_WILLNEED is not an option because 1. It would change the semantics: "Expect access in the near future." and "might be a good idea to read some pages" vs. "Definitely populate/ preallocate all memory and definitely fail on errors.". 2. Existing users (like virtio-balloon in QEMU when deflating the balloon) don't want populate/prealloc semantics. They treat this rather as a hint to give a little performance boost without too much overhead - and don't expect that a lot of memory might get consumed or a lot of time might be spent. IV. MADV_POPULATE_READ and MADV_POPULATE_WRITE Let's introduce MADV_POPULATE_READ and MADV_POPULATE_WRITE, inspired by MAP_POPULATE, with the following semantics: 1. MADV_POPULATE_READ can be used to prefault page tables just like manually reading each individual page. This will not break any COW mappings. The shared zero page might get mapped and no backend storage might get preallocated -- allocation might be deferred to write-fault time. Especially shared file mappings require an explicit fallocate() upfront to actually preallocate backend memory (blocks in the file system) in case the file might have holes. 2. If MADV_POPULATE_READ succeeds, all page tables have been populated (prefaulted) readable once. 3. MADV_POPULATE_WRITE can be used to preallocate backend memory and prefault page tables just like manually writing (or reading+writing) each individual page. This will break any COW mappings -- e.g., the shared zeropage is never populated. 4. If MADV_POPULATE_WRITE succeeds, all page tables have been populated (prefaulted) writable once. 5. MADV_POPULATE_READ and MADV_POPULATE_WRITE cannot be applied to special mappings marked with VM_PFNMAP and VM_IO. Also, proper access permissions (e.g., PROT_READ, PROT_WRITE) are required. If any such mapping is encountered, madvise() fails with -EINVAL. 6. If MADV_POPULATE_READ or MADV_POPULATE_WRITE fails, some page tables might have been populated. 7. MADV_POPULATE_READ and MADV_POPULATE_WRITE will return -EHWPOISON when encountering a HW poisoned page in the range. 8. Similar to MAP_POPULATE, MADV_POPULATE_READ and MADV_POPULATE_WRITE cannot protect from the OOM (Out Of Memory) handler killing the process. While the use case for MADV_POPULATE_WRITE is fairly obvious (i.e., preallocate memory and prefault page tables for VMs), one issue is that whenever we prefault pages writable, the pages have to be marked dirty, because the CPU could dirty them any time. while not a real problem for hugetlbfs or dax/pmem, it can be a problem for shared file mappings: each page will be marked dirty and has to be written back later when evicting. MADV_POPULATE_READ allows for optimizing this scenario: Pre-read a whole mapping from backend storage without marking it dirty, such that eviction won't have to write it back. As discussed above, shared file mappings might require an explciit fallocate() upfront to achieve preallcoation+prepopulation. Although sparse memory mappings are the primary use case, this will also be useful for other preallocate/prefault use cases where MAP_POPULATE is not desired or the semantics of MAP_POPULATE are not sufficient: as one example, QEMU users can trigger preallocation/prefaulting of guest RAM after the mapping was created -- and don't want errors to be silently suppressed. Looking at the history, MADV_POPULATE was already proposed in 2013 [1], however, the main motivation back than was performance improvements -- which should also still be the case. V. Single-threaded performance comparison I did a short experiment, prefaulting page tables on completely *empty mappings/files* and repeated the experiment 10 times. The results correspond to the shortest execution time. In general, the performance benefit for huge pages is negligible with small mappings. V.1: Private mappings POPULATE_READ and POPULATE_WRITE is fastest. Note that Reading/POPULATE_READ will populate the shared zeropage where applicable -- which result in short population times. The fastest way to allocate backend storage (here: swap or huge pages) and prefault page tables is POPULATE_WRITE. V.2: Shared mappings fallocate() is fastest, however, doesn't prefault page tables. POPULATE_WRITE is faster than simple writes and read/writes. POPULATE_READ is faster than simple reads. Without a fd, the fastest way to allocate backend storage and prefault page tables is POPULATE_WRITE. With an fd, the fastest way is usually FALLOCATE+POPULATE_READ or FALLOCATE+POPULATE_WRITE respectively; one exception are actual files: FALLOCATE+Read is slightly faster than FALLOCATE+POPULATE_READ. The fastest way to allocate backend storage prefault page tables is FALLOCATE+POPULATE_WRITE -- except when dealing with actual files; then, FALLOCATE+POPULATE_READ is fastest and won't directly mark all pages as dirty. v.3: Detailed results ================================================== 2 MiB MAP_PRIVATE: ************************************************** Anon 4 KiB : Read : 0.119 ms Anon 4 KiB : Write : 0.222 ms Anon 4 KiB : Read/Write : 0.380 ms Anon 4 KiB : POPULATE_READ : 0.060 ms Anon 4 KiB : POPULATE_WRITE : 0.158 ms Memfd 4 KiB : Read : 0.034 ms Memfd 4 KiB : Write : 0.310 ms Memfd 4 KiB : Read/Write : 0.362 ms Memfd 4 KiB : POPULATE_READ : 0.039 ms Memfd 4 KiB : POPULATE_WRITE : 0.229 ms Memfd 2 MiB : Read : 0.030 ms Memfd 2 MiB : Write : 0.030 ms Memfd 2 MiB : Read/Write : 0.030 ms Memfd 2 MiB : POPULATE_READ : 0.030 ms Memfd 2 MiB : POPULATE_WRITE : 0.030 ms tmpfs : Read : 0.033 ms tmpfs : Write : 0.313 ms tmpfs : Read/Write : 0.406 ms tmpfs : POPULATE_READ : 0.039 ms tmpfs : POPULATE_WRITE : 0.285 ms file : Read : 0.033 ms file : Write : 0.351 ms file : Read/Write : 0.408 ms file : POPULATE_READ : 0.039 ms file : POPULATE_WRITE : 0.290 ms hugetlbfs : Read : 0.030 ms hugetlbfs : Write : 0.030 ms hugetlbfs : Read/Write : 0.030 ms hugetlbfs : POPULATE_READ : 0.030 ms hugetlbfs : POPULATE_WRITE : 0.030 ms ************************************************** 4096 MiB MAP_PRIVATE: ************************************************** Anon 4 KiB : Read : 237.940 ms Anon 4 KiB : Write : 708.409 ms Anon 4 KiB : Read/Write : 1054.041 ms Anon 4 KiB : POPULATE_READ : 124.310 ms Anon 4 KiB : POPULATE_WRITE : 572.582 ms Memfd 4 KiB : Read : 136.928 ms Memfd 4 KiB : Write : 963.898 ms Memfd 4 KiB : Read/Write : 1106.561 ms Memfd 4 KiB : POPULATE_READ : 78.450 ms Memfd 4 KiB : POPULATE_WRITE : 805.881 ms Memfd 2 MiB : Read : 357.116 ms Memfd 2 MiB : Write : 357.210 ms Memfd 2 MiB : Read/Write : 357.606 ms Memfd 2 MiB : POPULATE_READ : 356.094 ms Memfd 2 MiB : POPULATE_WRITE : 356.937 ms tmpfs : Read : 137.536 ms tmpfs : Write : 954.362 ms tmpfs : Read/Write : 1105.954 ms tmpfs : POPULATE_READ : 80.289 ms tmpfs : POPULATE_WRITE : 822.826 ms file : Read : 137.874 ms file : Write : 987.025 ms file : Read/Write : 1107.439 ms file : POPULATE_READ : 80.413 ms file : POPULATE_WRITE : 857.622 ms hugetlbfs : Read : 355.607 ms hugetlbfs : Write : 355.729 ms hugetlbfs : Read/Write : 356.127 ms hugetlbfs : POPULATE_READ : 354.585 ms hugetlbfs : POPULATE_WRITE : 355.138 ms ************************************************** 2 MiB MAP_SHARED: ************************************************** Anon 4 KiB : Read : 0.394 ms Anon 4 KiB : Write : 0.348 ms Anon 4 KiB : Read/Write : 0.400 ms Anon 4 KiB : POPULATE_READ : 0.326 ms Anon 4 KiB : POPULATE_WRITE : 0.273 ms Anon 2 MiB : Read : 0.030 ms Anon 2 MiB : Write : 0.030 ms Anon 2 MiB : Read/Write : 0.030 ms Anon 2 MiB : POPULATE_READ : 0.030 ms Anon 2 MiB : POPULATE_WRITE : 0.030 ms Memfd 4 KiB : Read : 0.412 ms Memfd 4 KiB : Write : 0.372 ms Memfd 4 KiB : Read/Write : 0.419 ms Memfd 4 KiB : POPULATE_READ : 0.343 ms Memfd 4 KiB : POPULATE_WRITE : 0.288 ms Memfd 4 KiB : FALLOCATE : 0.137 ms Memfd 4 KiB : FALLOCATE+Read : 0.446 ms Memfd 4 KiB : FALLOCATE+Write : 0.330 ms Memfd 4 KiB : FALLOCATE+Read/Write : 0.454 ms Memfd 4 KiB : FALLOCATE+POPULATE_READ : 0.379 ms Memfd 4 KiB : FALLOCATE+POPULATE_WRITE : 0.268 ms Memfd 2 MiB : Read : 0.030 ms Memfd 2 MiB : Write : 0.030 ms Memfd 2 MiB : Read/Write : 0.030 ms Memfd 2 MiB : POPULATE_READ : 0.030 ms Memfd 2 MiB : POPULATE_WRITE : 0.030 ms Memfd 2 MiB : FALLOCATE : 0.030 ms Memfd 2 MiB : FALLOCATE+Read : 0.031 ms Memfd 2 MiB : FALLOCATE+Write : 0.031 ms Memfd 2 MiB : FALLOCATE+Read/Write : 0.031 ms Memfd 2 MiB : FALLOCATE+POPULATE_READ : 0.030 ms Memfd 2 MiB : FALLOCATE+POPULATE_WRITE : 0.030 ms tmpfs : Read : 0.416 ms tmpfs : Write : 0.369 ms tmpfs : Read/Write : 0.425 ms tmpfs : POPULATE_READ : 0.346 ms tmpfs : POPULATE_WRITE : 0.295 ms tmpfs : FALLOCATE : 0.139 ms tmpfs : FALLOCATE+Read : 0.447 ms tmpfs : FALLOCATE+Write : 0.333 ms tmpfs : FALLOCATE+Read/Write : 0.454 ms tmpfs : FALLOCATE+POPULATE_READ : 0.380 ms tmpfs : FALLOCATE+POPULATE_WRITE : 0.272 ms file : Read : 0.191 ms file : Write : 0.511 ms file : Read/Write : 0.524 ms file : POPULATE_READ : 0.196 ms file : POPULATE_WRITE : 0.434 ms file : FALLOCATE : 0.004 ms file : FALLOCATE+Read : 0.197 ms file : FALLOCATE+Write : 0.554 ms file : FALLOCATE+Read/Write : 0.480 ms file : FALLOCATE+POPULATE_READ : 0.201 ms file : FALLOCATE+POPULATE_WRITE : 0.381 ms hugetlbfs : Read : 0.030 ms hugetlbfs : Write : 0.030 ms hugetlbfs : Read/Write : 0.030 ms hugetlbfs : POPULATE_READ : 0.030 ms hugetlbfs : POPULATE_WRITE : 0.030 ms hugetlbfs : FALLOCATE : 0.030 ms hugetlbfs : FALLOCATE+Read : 0.031 ms hugetlbfs : FALLOCATE+Write : 0.031 ms hugetlbfs : FALLOCATE+Read/Write : 0.030 ms hugetlbfs : FALLOCATE+POPULATE_READ : 0.030 ms hugetlbfs : FALLOCATE+POPULATE_WRITE : 0.030 ms ************************************************** 4096 MiB MAP_SHARED: ************************************************** Anon 4 KiB : Read : 1053.090 ms Anon 4 KiB : Write : 913.642 ms Anon 4 KiB : Read/Write : 1060.350 ms Anon 4 KiB : POPULATE_READ : 893.691 ms Anon 4 KiB : POPULATE_WRITE : 782.885 ms Anon 2 MiB : Read : 358.553 ms Anon 2 MiB : Write : 358.419 ms Anon 2 MiB : Read/Write : 357.992 ms Anon 2 MiB : POPULATE_READ : 357.533 ms Anon 2 MiB : POPULATE_WRITE : 357.808 ms Memfd 4 KiB : Read : 1078.144 ms Memfd 4 KiB : Write : 942.036 ms Memfd 4 KiB : Read/Write : 1100.391 ms Memfd 4 KiB : POPULATE_READ : 925.829 ms Memfd 4 KiB : POPULATE_WRITE : 804.394 ms Memfd 4 KiB : FALLOCATE : 304.632 ms Memfd 4 KiB : FALLOCATE+Read : 1163.359 ms Memfd 4 KiB : FALLOCATE+Write : 933.186 ms Memfd 4 KiB : FALLOCATE+Read/Write : 1187.304 ms Memfd 4 KiB : FALLOCATE+POPULATE_READ : 1013.660 ms Memfd 4 KiB : FALLOCATE+POPULATE_WRITE : 794.560 ms Memfd 2 MiB : Read : 358.131 ms Memfd 2 MiB : Write : 358.099 ms Memfd 2 MiB : Read/Write : 358.250 ms Memfd 2 MiB : POPULATE_READ : 357.563 ms Memfd 2 MiB : POPULATE_WRITE : 357.334 ms Memfd 2 MiB : FALLOCATE : 356.735 ms Memfd 2 MiB : FALLOCATE+Read : 358.152 ms Memfd 2 MiB : FALLOCATE+Write : 358.331 ms Memfd 2 MiB : FALLOCATE+Read/Write : 358.018 ms Memfd 2 MiB : FALLOCATE+POPULATE_READ : 357.286 ms Memfd 2 MiB : FALLOCATE+POPULATE_WRITE : 357.523 ms tmpfs : Read : 1087.265 ms tmpfs : Write : 950.840 ms tmpfs : Read/Write : 1107.567 ms tmpfs : POPULATE_READ : 922.605 ms tmpfs : POPULATE_WRITE : 810.094 ms tmpfs : FALLOCATE : 306.320 ms tmpfs : FALLOCATE+Read : 1169.796 ms tmpfs : FALLOCATE+Write : 933.730 ms tmpfs : FALLOCATE+Read/Write : 1191.610 ms tmpfs : FALLOCATE+POPULATE_READ : 1020.474 ms tmpfs : FALLOCATE+POPULATE_WRITE : 798.945 ms file : Read : 654.101 ms file : Write : 1259.142 ms file : Read/Write : 1289.509 ms file : POPULATE_READ : 661.642 ms file : POPULATE_WRITE : 1106.816 ms file : FALLOCATE : 1.864 ms file : FALLOCATE+Read : 656.328 ms file : FALLOCATE+Write : 1153.300 ms file : FALLOCATE+Read/Write : 1180.613 ms file : FALLOCATE+POPULATE_READ : 668.347 ms file : FALLOCATE+POPULATE_WRITE : 996.143 ms hugetlbfs : Read : 357.245 ms hugetlbfs : Write : 357.413 ms hugetlbfs : Read/Write : 357.120 ms hugetlbfs : POPULATE_READ : 356.321 ms hugetlbfs : POPULATE_WRITE : 356.693 ms hugetlbfs : FALLOCATE : 355.927 ms hugetlbfs : FALLOCATE+Read : 357.074 ms hugetlbfs : FALLOCATE+Write : 357.120 ms hugetlbfs : FALLOCATE+Read/Write : 356.983 ms hugetlbfs : FALLOCATE+POPULATE_READ : 356.413 ms hugetlbfs : FALLOCATE+POPULATE_WRITE : 356.266 ms ************************************************** [1] https://lkml.org/lkml/2013/6/27/698 [akpm@linux-foundation.org: coding style fixes] Link: https://lkml.kernel.org/r/20210419135443.12822-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@surriel.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rolf Eike Beer <eike-kernel@sf-tec.de> Cc: Ram Pai <linuxram@us.ibm.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Andrea Arcangeli
|
a458b76a41 |
mm: gup: pack has_pinned in MMF_HAS_PINNED
has_pinned 32bit can be packed in the MMF_HAS_PINNED bit as a noop cleanup. Any atomic_inc/dec to the mm cacheline shared by all threads in pin-fast would reintroduce a loss of SMP scalability to pin-fast, so there's no future potential usefulness to keep an atomic in the mm for this. set_bit(MMF_HAS_PINNED) will be theoretically a bit slower than WRITE_ONCE (atomic_set is equivalent to WRITE_ONCE), but the set_bit (just like atomic_set after this commit) has to be still issued only once per "mm", so the difference between the two will be lost in the noise. will-it-scale "mmap2" shows no change in performance with enterprise config as expected. will-it-scale "pin_fast" retains the > 4000% SMP scalability performance improvement against upstream as expected. This is a noop as far as overall performance and SMP scalability are concerned. [peterx@redhat.com: pack has_pinned in MMF_HAS_PINNED] Link: https://lkml.kernel.org/r/YJqWESqyxa8OZA+2@t490s [akpm@linux-foundation.org: coding style fixes] [peterx@redhat.com: fix build for task_mmu.c, introduce mm_set_has_pinned_flag, fix comments] Link: https://lkml.kernel.org/r/20210507150553.208763-4-peterx@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Kirill Shutemov <kirill@shutemov.name> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Andrea Arcangeli
|
292648ac5c |
mm: gup: allow FOLL_PIN to scale in SMP
has_pinned cannot be written by each pin-fast or it won't scale in SMP. This isn't "false sharing" strictly speaking (it's more like "true non-sharing"), but it creates the same SMP scalability bottleneck of "false sharing". To verify the improvement, below test is done on 40 cpus host with Intel(R) Xeon(R) CPU E5-2630 v4 @ 2.20GHz (must be with CONFIG_GUP_TEST=y): $ sudo chrt -f 1 ./gup_test -a -m 512 -j 40 Where we can get (average value for 40 threads): Old kernel: 477729.97 (+- 3.79%) New kernel: 89144.65 (+-11.76%) On a similar condition with 256 cpus, this commits increases the SMP scalability of pin_user_pages_fast() executed by different threads of the same process by more than 4000%. [peterx@redhat.com: rewrite commit message, add parentheses against "(A & B)"] Link: https://lkml.kernel.org/r/20210507150553.208763-3-peterx@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Kirill Shutemov <kirill@shutemov.name> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Jann Horn
|
c24d373225 |
mm/gup: fix try_grab_compound_head() race with split_huge_page()
try_grab_compound_head() is used to grab a reference to a page from
get_user_pages_fast(), which is only protected against concurrent freeing
of page tables (via local_irq_save()), but not against concurrent TLB
flushes, freeing of data pages, or splitting of compound pages.
Because no reference is held to the page when try_grab_compound_head() is
called, the page may have been freed and reallocated by the time its
refcount has been elevated; therefore, once we're holding a stable
reference to the page, the caller re-checks whether the PTE still points
to the same page (with the same access rights).
The problem is that try_grab_compound_head() has to grab a reference on
the head page; but between the time we look up what the head page is and
the time we actually grab a reference on the head page, the compound page
may have been split up (either explicitly through split_huge_page() or by
freeing the compound page to the buddy allocator and then allocating its
individual order-0 pages). If that happens, get_user_pages_fast() may end
up returning the right page but lifting the refcount on a now-unrelated
page, leading to use-after-free of pages.
To fix it: Re-check whether the pages still belong together after lifting
the refcount on the head page. Move anything else that checks
compound_head(page) below the refcount increment.
This can't actually happen on bare-metal x86 (because there, disabling
IRQs locks out remote TLB flushes), but it can happen on virtualized x86
(e.g. under KVM) and probably also on arm64. The race window is pretty
narrow, and constantly allocating and shattering hugepages isn't exactly
fast; for now I've only managed to reproduce this in an x86 KVM guest with
an artificially widened timing window (by adding a loop that repeatedly
calls `inl(0x3f8 + 5)` in `try_get_compound_head()` to force VM exits, so
that PV TLB flushes are used instead of IPIs).
As requested on the list, also replace the existing VM_BUG_ON_PAGE() with
a warning and bailout. Since the existing code only performed the BUG_ON
check on DEBUG_VM kernels, ensure that the new code also only performs the
check under that configuration - I don't want to mix two logically
separate changes together too much. The macro VM_WARN_ON_ONCE_PAGE()
doesn't return a value on !DEBUG_VM, so wrap the whole check in an #ifdef
block. An alternative would be to change the VM_WARN_ON_ONCE_PAGE()
definition for !DEBUG_VM such that it always returns false, but since that
would differ from the behavior of the normal WARN macros, it might be too
confusing for readers.
Link: https://lkml.kernel.org/r/20210615012014.1100672-1-jannh@google.com
Fixes:
|
||
Michal Hocko
|
f10628d2f6 |
Revert "mm/gup: check page posion status for coredump."
While reviewing [1] I came across commit |
||
Ingo Molnar
|
f0953a1bba |
mm: fix typos in comments
Fix ~94 single-word typos in locking code comments, plus a few very obvious grammar mistakes. Link: https://lkml.kernel.org/r/20210322212624.GA1963421@gmail.com Link: https://lore.kernel.org/r/20210322205203.GB1959563@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Cc: Bhaskar Chowdhury <unixbhaskar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Pavel Tatashin
|
f68749ec34 |
mm/gup: longterm pin migration cleanup
When pages are longterm pinned, we must migrated them out of movable zone. The function that migrates them has a hidden loop with goto. The loop is to retry on isolation failures, and after successful migration. Make this code better by moving this loop to the caller. Link: https://lkml.kernel.org/r/20210215161349.246722-13-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Pavel Tatashin
|
24dc20c75f |
mm/gup: change index type to long as it counts pages
In __get_user_pages_locked() i counts number of pages which should be long, as long is used in all other places to contain number of pages, and 32-bit becomes increasingly small for handling page count proportional values. Link: https://lkml.kernel.org/r/20210215161349.246722-12-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Pavel Tatashin
|
d1e153fea2 |
mm/gup: migrate pinned pages out of movable zone
We should not pin pages in ZONE_MOVABLE. Currently, we do not pin only movable CMA pages. Generalize the function that migrates CMA pages to migrate all movable pages. Use is_pinnable_page() to check which pages need to be migrated Link: https://lkml.kernel.org/r/20210215161349.246722-10-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Pavel Tatashin
|
1a08ae36cf |
mm cma: rename PF_MEMALLOC_NOCMA to PF_MEMALLOC_PIN
PF_MEMALLOC_NOCMA is used ot guarantee that the allocator will not return pages that might belong to CMA region. This is currently used for long term gup to make sure that such pins are not going to be done on any CMA pages. When PF_MEMALLOC_NOCMA has been introduced we haven't realized that it is focusing on CMA pages too much and that there is larger class of pages that need the same treatment. MOVABLE zone cannot contain any long term pins as well so it makes sense to reuse and redefine this flag for that usecase as well. Rename the flag to PF_MEMALLOC_PIN which defines an allocation context which can only get pages suitable for long-term pins. Also rename: memalloc_nocma_save()/memalloc_nocma_restore to memalloc_pin_save()/memalloc_pin_restore() and make the new functions common. [rppt@linux.ibm.com: fix renaming of PF_MEMALLOC_NOCMA to PF_MEMALLOC_PIN] Link: https://lkml.kernel.org/r/20210331163816.11517-1-rppt@kernel.org Link: https://lkml.kernel.org/r/20210215161349.246722-6-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Pavel Tatashin
|
6e7f34ebb8 |
mm/gup: check for isolation errors
It is still possible that we pin movable CMA pages if there are
isolation errors and cma_page_list stays empty when we check again.
Check for isolation errors, and return success only when there are no
isolation errors, and cma_page_list is empty after checking.
Because isolation errors are transient, we retry indefinitely.
Link: https://lkml.kernel.org/r/20210215161349.246722-5-pasha.tatashin@soleen.com
Fixes:
|
||
|
Pavel Tatashin
|
f0f4463837 |
mm/gup: return an error on migration failure
When migration failure occurs, we still pin pages, which means that we may pin CMA movable pages which should never be the case. Instead return an error without pinning pages when migration failure happens. No need to retry migrating, because migrate_pages() already retries 10 times. Link: https://lkml.kernel.org/r/20210215161349.246722-4-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Pavel Tatashin
|
83c02c23d0 |
mm/gup: check every subpage of a compound page during isolation
When pages are isolated in check_and_migrate_movable_pages() we skip
compound number of pages at a time. However, as Jason noted, it is not
necessary correct that pages[i] corresponds to the pages that we
skipped. This is because it is possible that the addresses in this
range had split_huge_pmd()/split_huge_pud(), and these functions do not
update the compound page metadata.
The problem can be reproduced if something like this occurs:
1. User faulted huge pages.
2. split_huge_pmd() was called for some reason
3. User has unmapped some sub-pages in the range
4. User tries to longterm pin the addresses.
The resulting pages[i] might end-up having pages which are not compound
size page aligned.
Link: https://lkml.kernel.org/r/20210215161349.246722-3-pasha.tatashin@soleen.com
Fixes:
|
||
|
Pavel Tatashin
|
c991ffef7b |
mm/gup: don't pin migrated cma pages in movable zone
Patch series "prohibit pinning pages in ZONE_MOVABLE", v11. When page is pinned it cannot be moved and its physical address stays the same until pages is unpinned. This is useful functionality to allows userland to implementation DMA access. For example, it is used by vfio in vfio_pin_pages(). However, this functionality breaks memory hotplug/hotremove assumptions that pages in ZONE_MOVABLE can always be migrated. This patch series fixes this issue by forcing new allocations during page pinning to omit ZONE_MOVABLE, and also to migrate any existing pages from ZONE_MOVABLE during pinning. It uses the same scheme logic that is currently used by CMA, and extends the functionality for all allocations. For more information read the discussion [1] about this problem. [1] https://lore.kernel.org/lkml/CA+CK2bBffHBxjmb9jmSKacm0fJMinyt3Nhk8Nx6iudcQSj80_w@mail.gmail.com This patch (of 14): In order not to fragment CMA the pinned pages are migrated. However, they are migrated to ZONE_MOVABLE, which also should not have pinned pages. Remove __GFP_MOVABLE, so pages can be migrated to zones where pinning is allowed. Link: https://lkml.kernel.org/r/20210215161349.246722-1-pasha.tatashin@soleen.com Link: https://lkml.kernel.org/r/20210215161349.246722-2-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: David Hildenbrand <david@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Sasha Levin <sashal@kernel.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: David Rientjes <rientjes@google.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Yang Shi
|
4066c11948 |
mm: gup: remove FOLL_SPLIT
Since commit |
||
Joao Martins
|
458a4f788f |
mm/gup: add a range variant of unpin_user_pages_dirty_lock()
Add an unpin_user_page_range_dirty_lock() API which takes a starting page and how many consecutive pages we want to unpin and optionally dirty. To that end, define another iterator for_each_compound_range() that operates in page ranges as opposed to page array. For users (like RDMA mr_dereg) where each sg represents a contiguous set of pages, we're able to more efficiently unpin pages without having to supply an array of pages much of what happens today with unpin_user_pages(). Link: https://lkml.kernel.org/r/20210212130843.13865-4-joao.m.martins@oracle.com Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Doug Ledford <dledford@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Joao Martins
|
31b912de13 |
mm/gup: decrement head page once for group of subpages
Rather than decrementing the head page refcount one by one, we walk the page array and checking which belong to the same compound_head. Later on we decrement the calculated amount of references in a single write to the head page. To that end switch to for_each_compound_head() does most of the work. set_page_dirty() needs no adjustment as it's a nop for non-dirty head pages and it doesn't operate on tail pages. This considerably improves unpinning of pages with THP and hugetlbfs: - THP gup_test -t -m 16384 -r 10 [-L|-a] -S -n 512 -w PIN_LONGTERM_BENCHMARK (put values): ~87.6k us -> ~23.2k us - 16G with 1G huge page size gup_test -f /mnt/huge/file -m 16384 -r 10 [-L|-a] -S -n 512 -w PIN_LONGTERM_BENCHMARK: (put values): ~87.6k us -> ~27.5k us Link: https://lkml.kernel.org/r/20210212130843.13865-3-joao.m.martins@oracle.com Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Doug Ledford <dledford@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Joao Martins
|
8745d7f634 |
mm/gup: add compound page list iterator
Patch series "mm/gup: page unpining improvements", v4. This series improves page unpinning, with an eye on improving MR deregistration for big swaths of memory (which is bound by the page unpining), particularly: 1) Decrement the head page by @ntails and thus reducing a lot the number of atomic operations per compound page. This is done by comparing individual tail pages heads, and counting number of consecutive tails on which they match heads and based on that update head page refcount. Should have a visible improvement in all page (un)pinners which use compound pages 2) Introducing a new API for unpinning page ranges (to avoid the trick in the previous item and be based on math), and use that in RDMA ib_mem_release (used for mr deregistration). Performance improvements: unpin_user_pages() for hugetlbfs and THP improves ~3x (through gup_test) and RDMA MR dereg improves ~4.5x with the new API. See patches 2 and 4 for those. This patch (of 4): Add a helper that iterates over head pages in a list of pages. It essentially counts the tails until the next page to process has a different head that the current. This is going to be used by unpin_user_pages() family of functions, to batch the head page refcount updates once for all passed consecutive tail pages. Link: https://lkml.kernel.org/r/20210212130843.13865-1-joao.m.martins@oracle.com Link: https://lkml.kernel.org/r/20210212130843.13865-2-joao.m.martins@oracle.com Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Doug Ledford <dledford@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Aili Yao
|
d3378e86d1 |
mm/gup: check page posion status for coredump.
When we do coredump for user process signal, this may be an SIGBUS signal with BUS_MCEERR_AR or BUS_MCEERR_AO code, which means this signal is resulted from ECC memory fail like SRAR or SRAO, we expect the memory recovery work is finished correctly, then the get_dump_page() will not return the error page as its process pte is set invalid by memory_failure(). But memory_failure() may fail, and the process's related pte may not be correctly set invalid, for current code, we will return the poison page, get it dumped, and then lead to system panic as its in kernel code. So check the poison status in get_dump_page(), and if TRUE, return NULL. There maybe other scenario that is also better to check the posion status and not to panic, so make a wrapper for this check, Thanks to David's suggestion(<david@redhat.com>). [akpm@linux-foundation.org: s/0/false/] [yaoaili@kingsoft.com: is_page_poisoned() arg cannot be null, per Matthew] Link: https://lkml.kernel.org/r/20210322115233.05e4e82a@alex-virtual-machine Link: https://lkml.kernel.org/r/20210319104437.6f30e80d@alex-virtual-machine Signed-off-by: Aili Yao <yaoaili@kingsoft.com> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Aili Yao <yaoaili@kingsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Joao Martins
|
0fa5bc4023 |
mm/hugetlb: grab head page refcount once for group of subpages
Patch series "mm/hugetlb: follow_hugetlb_page() improvements", v2. While looking at ZONE_DEVICE struct page reuse particularly the last patch[0], I found two possible improvements for follow_hugetlb_page() which is solely used for get_user_pages()/pin_user_pages(). The first patch batches page refcount updates while the second tidies up storing the subpages/vmas. Both together bring the cost of slow variant of gup() cost from ~87.6k usecs to ~5.8k usecs. libhugetlbfs tests seem to pass as well gup_test benchmarks with hugetlbfs vmas. This patch (of 2): follow_hugetlb_page() once it locks the pmd/pud, checks all its N subpages in a huge page and grabs a reference for each one. Similar to gup-fast, have follow_hugetlb_page() grab the head page refcount only after counting all its subpages that are part of the just faulted huge page. Consequently we reduce the number of atomics necessary to pin said huge page, which improves non-fast gup() considerably: - 16G with 1G huge page size gup_test -f /mnt/huge/file -m 16384 -r 10 -L -S -n 512 -w PIN_LONGTERM_BENCHMARK: ~87.6k us -> ~12.8k us Link: https://lkml.kernel.org/r/20210128182632.24562-1-joao.m.martins@oracle.com Link: https://lkml.kernel.org/r/20210128182632.24562-2-joao.m.martins@oracle.com Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Linus Torvalds
|
ac73e3dc8a |
Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
- a few random little subsystems
- almost all of the MM patches which are staged ahead of linux-next
material. I'll trickle to post-linux-next work in as the dependents
get merged up.
Subsystems affected by this patch series: kthread, kbuild, ide, ntfs,
ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache,
gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation,
kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc,
uaccess, zram, and cleanups).
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits)
mm: cleanup kstrto*() usage
mm: fix fall-through warnings for Clang
mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at
mm: shmem: convert shmem_enabled_show to use sysfs_emit_at
mm:backing-dev: use sysfs_emit in macro defining functions
mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening
mm: use sysfs_emit for struct kobject * uses
mm: fix kernel-doc markups
zram: break the strict dependency from lzo
zram: add stat to gather incompressible pages since zram set up
zram: support page writeback
mm/process_vm_access: remove redundant initialization of iov_r
mm/zsmalloc.c: rework the list_add code in insert_zspage()
mm/zswap: move to use crypto_acomp API for hardware acceleration
mm/zswap: fix passing zero to 'PTR_ERR' warning
mm/zswap: make struct kernel_param_ops definitions const
userfaultfd/selftests: hint the test runner on required privilege
userfaultfd/selftests: fix retval check for userfaultfd_open()
userfaultfd/selftests: always dump something in modes
userfaultfd: selftests: make __{s,u}64 format specifiers portable
...
|
||
Mauro Carvalho Chehab
|
a00cda3f0a |
mm: fix kernel-doc markups
Kernel-doc markups should use this format:
identifier - description
Fix some issues on mm files:
1) The definition for get_user_pages_locked() doesn't follow it. Also,
it expects a short descrpition at the header, followed by a long one,
after the parameters. Fix it.
2) Kernel-doc requires that a kernel-doc markup to be immediately below
the function prototype, as otherwise it will rename it. So, move
get_pfnblock_flags_mask() description to the right place.
3) Make invalidate_mapping_pagevec() to also follow the expected
kernel-doc format.
While here, fix a few minor English syntax issues, as suggested
by Matthew:
will used -> will be used
similar with -> similar to
Link: https://lkml.kernel.org/r/80e85dddc92d333bc2159ee8a2294921612e8745.1605521731.git.mchehab+huawei@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Suggested-by: Mattew Wilcox <willy@infradead.org> [English fixes]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Jason Gunthorpe
|
4509b42c38 |
mm/gup: combine put_compound_head() and unpin_user_page()
These functions accomplish the same thing but have different
implementations.
unpin_user_page() has a bug where it calls mod_node_page_state() after
calling put_page() which creates a risk that the page could have been
hot-uplugged from the system.
Fix this by using put_compound_head() as the only implementation.
__unpin_devmap_managed_user_page() and related can be deleted as well in
favour of the simpler, but slower, version in put_compound_head() that has
an extra atomic page_ref_sub, but always calls put_page() which internally
contains the special devmap code.
Move put_compound_head() to be directly after try_grab_compound_head() so
people can find it in future.
Link: https://lkml.kernel.org/r/0-v1-6730d4ee0d32+40e6-gup_combine_put_jgg@nvidia.com
Fixes:
|
||
|
Jason Gunthorpe
|
52650c8b46 |
mm/gup: remove the vma allocation from gup_longterm_locked()
Long ago there wasn't a FOLL_LONGTERM flag so this DAX check was done by post-processing the VMA list. These days it is trivial to just check each VMA to see if it is DAX before processing it inside __get_user_pages() and return failure if a DAX VMA is encountered with FOLL_LONGTERM. Removing the allocation of the VMA list is a significant speed up for many call sites. Add an IS_ENABLED to vma_is_fsdax so that code generation is unchanged when DAX is compiled out. Remove the dummy version of __gup_longterm_locked() as !CONFIG_CMA already makes memalloc_nocma_save(), check_and_migrate_cma_pages(), and memalloc_nocma_restore() into a NOP. Link: https://lkml.kernel.org/r/0-v1-5551df3ed12e+b8-gup_dax_speedup_jgg@nvidia.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Jason Gunthorpe
|
57efa1fe59 |
mm/gup: prevent gup_fast from racing with COW during fork
Since commit |
||
|
Jason Gunthorpe
|
c28b1fc703 |
mm/gup: reorganize internal_get_user_pages_fast()
Patch series "Add a seqcount between gup_fast and copy_page_range()", v4. As discussed and suggested by Linus use a seqcount to close the small race between gup_fast and copy_page_range(). Ahmed confirms that raw_write_seqcount_begin() is the correct API to use in this case and it doesn't trigger any lockdeps. I was able to test it using two threads, one forking and the other using ibv_reg_mr() to trigger GUP fast. Modifying copy_page_range() to sleep made the window large enough to reliably hit to test the logic. This patch (of 2): The next patch in this series makes the lockless flow a little more complex, so move the entire block into a new function and remove a level of indention. Tidy a bit of cruft: - addr is always the same as start, so use start - Use the modern check_add_overflow() for computing end = start + len - nr_pinned/pages << PAGE_SHIFT needs the LHS to be unsigned long to avoid shift overflow, make the variables unsigned long to avoid coding casts in both places. nr_pinned was missing its cast - The handling of ret and nr_pinned can be streamlined a bit No functional change. Link: https://lkml.kernel.org/r/0-v4-908497cf359a+4782-gup_fork_jgg@nvidia.com Link: https://lkml.kernel.org/r/1-v4-908497cf359a+4782-gup_fork_jgg@nvidia.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Peter Zijlstra
|
2a4a06da8a |
mm/gup: Provide gup_get_pte() more generic
In order to write another lockless page-table walker, we need gup_get_pte() exposed. While doing that, rename it to ptep_get_lockless() to match the existing ptep_get() naming. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20201126121121.036370527@infradead.org |
||
|
Jason Gunthorpe
|
96e1fac162 |
mm/gup: use unpin_user_pages() in __gup_longterm_locked()
When FOLL_PIN is passed to __get_user_pages() the page list must be put
back using unpin_user_pages() otherwise the page pin reference persists
in a corrupted state.
There are two places in the unwind of __gup_longterm_locked() that put
the pages back without checking. Normally on error this function would
return the partial page list making this the caller's responsibility,
but in these two cases the caller is not allowed to see these pages at
all.
Fixes:
|
||
|
Jann Horn
|
7f3bfab52c |
mm/gup: take mmap_lock in get_dump_page()
Properly take the mmap_lock before calling into the GUP code from get_dump_page(); and play nice, allowing the GUP code to drop the mmap_lock if it has to sleep. As Linus pointed out, we don't actually need the VMA because __get_user_pages() will flush the dcache for us if necessary. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200827114932.3572699-7-jannh@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Jann Horn
|
8f942eea12 |
binfmt_elf_fdpic: stop using dump_emit() on user pointers on !MMU
Patch series "Fix ELF / FDPIC ELF core dumping, and use mmap_lock properly in there", v5. At the moment, we have that rather ugly mmget_still_valid() helper to work around <https://crbug.com/project-zero/1790>: ELF core dumping doesn't take the mmap_sem while traversing the task's VMAs, and if anything (like userfaultfd) then remotely messes with the VMA tree, fireworks ensue. So at the moment we use mmget_still_valid() to bail out in any writers that might be operating on a remote mm's VMAs. With this series, I'm trying to get rid of the need for that as cleanly as possible. ("cleanly" meaning "avoid holding the mmap_lock across unbounded sleeps".) Patches 1, 2, 3 and 4 are relatively unrelated cleanups in the core dumping code. Patches 5 and 6 implement the main change: Instead of repeatedly accessing the VMA list with sleeps in between, we snapshot it at the start with proper locking, and then later we just use our copy of the VMA list. This ensures that the kernel won't crash, that VMA metadata in the coredump is consistent even in the presence of concurrent modifications, and that any virtual addresses that aren't being concurrently modified have their contents show up in the core dump properly. The disadvantage of this approach is that we need a bit more memory during core dumping for storing metadata about all VMAs. At the end of the series, patch 7 removes the old workaround for this issue (mmget_still_valid()). I have tested: - Creating a simple core dump on X86-64 still works. - The created coredump on X86-64 opens in GDB and looks plausible. - X86-64 core dumps contain the first page for executable mappings at offset 0, and don't contain the first page for non-executable file mappings or executable mappings at offset !=0. - NOMMU 32-bit ARM can still generate plausible-looking core dumps through the FDPIC implementation. (I can't test this with GDB because GDB is missing some structure definition for nommu ARM, but I've poked around in the hexdump and it looked decent.) This patch (of 7): dump_emit() is for kernel pointers, and VMAs describe userspace memory. Let's be tidy here and avoid accessing userspace pointers under KERNEL_DS, even if it probably doesn't matter much on !MMU systems - especially given that it looks like we can just use the same get_dump_page() as on MMU if we move it out of the CONFIG_MMU block. One small change we have to make in get_dump_page() is to use __get_user_pages_locked() instead of __get_user_pages(), since the latter doesn't exist on nommu. On mmu builds, __get_user_pages_locked() will just call __get_user_pages() for us. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200827114932.3572699-1-jannh@google.com Link: http://lkml.kernel.org/r/20200827114932.3572699-2-jannh@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
John Hubbard
|
146608bb75 |
mm/gup: protect unpin_user_pages() against npages==-ERRNO
As suggested by Dan Carpenter, fortify unpin_user_pages() just a bit, against a typical caller mistake: check if the npages arg is really a -ERRNO value, which would blow up the unpinning loop: WARN and return. If this new WARN_ON() fires, then the system *might* be leaking pages (by leaving them pinned), but probably not. More likely, gup/pup returned a hard -ERRNO error to the caller, who erroneously passed it here. Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Souptick Joarder <jrdr.linux@gmail.com> Link: https://lkml.kernel.org/r/20200917065706.409079-1-jhubbard@nvidia.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Barry Song
|
447f3e45c1 |
mm/gup: don't permit users to call get_user_pages with FOLL_LONGTERM
gup prohibits users from calling get_user_pages() with FOLL_PIN. But it allows users to call get_user_pages() with FOLL_LONGTERM only. It seems insensible. Since FOLL_LONGTERM is a stricter case of FOLL_PIN, we should prohibit users from calling get_user_pages() with FOLL_LONGTERM while not with FOLL_PIN. mm/gup_benchmark.c used to be the only user who did this improperly. But it has been fixed by moving to use pin_user_pages(). [akpm@linux-foundation.org: fix CONFIG_MMU=n build] Link: https://lkml.kernel.org/r/CA+G9fYuNS3k0DVT62twfV746pfNhCSrk5sVMcOcQ1PGGnEseyw@mail.gmail.com Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jan Kara <jack@suse.cz> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Link: http://lkml.kernel.org/r/20200819110100.23504-1-song.bao.hua@hisilicon.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Jason A. Donenfeld
|
a4d63c3732 |
mm: do not rely on mm == current->mm in __get_user_pages_locked
It seems likely this block was pasted from internal_get_user_pages_fast,
which is not passed an mm struct and therefore uses current's. But
__get_user_pages_locked is passed an explicit mm, and current->mm is not
always valid. This was hit when being called from i915, which uses:
pin_user_pages_remote->
__get_user_pages_remote->
__gup_longterm_locked->
__get_user_pages_locked
Before, this would lead to an OOPS:
BUG: kernel NULL pointer dereference, address: 0000000000000064
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
CPU: 10 PID: 1431 Comm: kworker/u33:1 Tainted: P S U O 5.9.0-rc7+ #140
Hardware name: LENOVO 20QTCTO1WW/20QTCTO1WW, BIOS N2OET47W (1.34 ) 08/06/2020
Workqueue: i915-userptr-acquire __i915_gem_userptr_get_pages_worker [i915]
RIP: 0010:__get_user_pages_remote+0xd7/0x310
Call Trace:
__i915_gem_userptr_get_pages_worker+0xc8/0x260 [i915]
process_one_work+0x1ca/0x390
worker_thread+0x48/0x3c0
kthread+0x114/0x130
ret_from_fork+0x1f/0x30
CR2: 0000000000000064
This commit fixes the problem by using the mm pointer passed to the
function rather than the bogus one in current.
Fixes:
|
||
|
Peter Xu
|
008cfe4418 |
mm: Introduce mm_struct.has_pinned
(Commit message majorly collected from Jason Gunthorpe) Reduce the chance of false positive from page_maybe_dma_pinned() by keeping track if the mm_struct has ever been used with pin_user_pages(). This allows cases that might drive up the page ref_count to avoid any penalty from handling dma_pinned pages. Future work is planned, to provide a more sophisticated solution, likely to turn it into a real counter. For now, make it atomic_t but use it as a boolean for simplicity. Suggested-by: Jason Gunthorpe <jgg@ziepe.ca> Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Vasily Gorbik
|
d3f7b1bb20 |
mm/gup: fix gup_fast with dynamic page table folding
Currently to make sure that every page table entry is read just once
gup_fast walks perform READ_ONCE and pass pXd value down to the next
gup_pXd_range function by value e.g.:
static int gup_pud_range(p4d_t p4d, unsigned long addr, unsigned long end,
unsigned int flags, struct page **pages, int *nr)
...
pudp = pud_offset(&p4d, addr);
This function passes a reference on that local value copy to pXd_offset,
and might get the very same pointer in return. This happens when the
level is folded (on most arches), and that pointer should not be
iterated.
On s390 due to the fact that each task might have different 5,4 or
3-level address translation and hence different levels folded the logic
is more complex and non-iteratable pointer to a local copy leads to
severe problems.
Here is an example of what happens with gup_fast on s390, for a task
with 3-level paging, crossing a 2 GB pud boundary:
// addr = 0x1007ffff000, end = 0x10080001000
static int gup_pud_range(p4d_t p4d, unsigned long addr, unsigned long end,
unsigned int flags, struct page **pages, int *nr)
{
unsigned long next;
pud_t *pudp;
// pud_offset returns &p4d itself (a pointer to a value on stack)
pudp = pud_offset(&p4d, addr);
do {
// on second iteratation reading "random" stack value
pud_t pud = READ_ONCE(*pudp);
// next = 0x10080000000, due to PUD_SIZE/MASK != PGDIR_SIZE/MASK on s390
next = pud_addr_end(addr, end);
...
} while (pudp++, addr = next, addr != end); // pudp++ iterating over stack
return 1;
}
This happens since s390 moved to common gup code with commit
|
||
|
Linus Torvalds
|
b25d1dc947 |
Merge branch 'simplify-do_wp_page'
Merge emailed patches from Peter Xu:
"This is a small series that I picked up from Linus's suggestion to
simplify cow handling (and also make it more strict) by checking
against page refcounts rather than mapcounts.
This makes uffd-wp work again (verified by running upmapsort)"
Note: this is horrendously bad timing, and making this kind of
fundamental vm change after -rc3 is not at all how things should work.
The saving grace is that it really is a a nice simplification:
8 files changed, 29 insertions(+), 120 deletions(-)
The reason for the bad timing is that it turns out that commit
|
||
|
Peter Xu
|
a308c71bf1 |
mm/gup: Remove enfornced COW mechanism
With the more strict (but greatly simplified) page reuse logic in do_wp_page(), we can safely go back to the world where cow is not enforced with writes. This essentially reverts commit |
||
|
Linus Torvalds
|
8381979dfa |
Merge branch 'gate-page-refcount' (patches from Dave Hansen)
Merge gate page refcount fix from Dave Hansen: "During the conversion over to pin_user_pages(), gate pages were missed. The fix is pretty simple, and is accompanied by a new test from Andy which probably would have caught this earlier" * emailed patches from Dave Hansen <dave.hansen@linux.intel.com>: selftests/x86/test_vsyscall: Improve the process_vm_readv() test mm: fix pin vs. gup mismatch with gate pages |
||
Dave Hansen
|
9fa2dd9467 |
mm: fix pin vs. gup mismatch with gate pages
Gate pages were missed when converting from get to pin_user_pages(). This can lead to refcount imbalances. This is reliably and quickly reproducible running the x86 selftests when vsyscall=emulate is enabled (the default). Fix by using try_grab_page() with appropriate flags passed. The long story: Today, pin_user_pages() and get_user_pages() are similar interfaces for manipulating page reference counts. However, "pins" use a "bias" value and manipulate the actual reference count by 1024 instead of 1 used by plain "gets". That means that pin_user_pages() must be matched with unpin_user_pages() and can't be mixed with a plain put_user_pages() or put_page(). Enter gate pages, like the vsyscall page. They are pages usually in the kernel image, but which are mapped to userspace. Userspace is allowed access to them, including interfaces using get/pin_user_pages(). The refcount of these kernel pages is manipulated just like a normal user page on the get/pin side so that the put/unpin side can work the same for normal user pages or gate pages. get_gate_page() uses try_get_page() which only bumps the refcount by 1, not 1024, even if called in the pin_user_pages() path. If someone pins a gate page, this happens: pin_user_pages() get_gate_page() try_get_page() // bump refcount +1 ... some time later unpin_user_pages() page_ref_sub_and_test(page, 1024)) ... and boom, we get a refcount off by 1023. This is reliably and quickly reproducible running the x86 selftests when booted with vsyscall=emulate (the default). The selftests use ptrace(), but I suspect anything using pin_user_pages() on gate pages could hit this. To fix it, simply use try_grab_page() instead of try_get_page(), and pass 'gup_flags' in so that FOLL_PIN can be respected. This bug traces back to the very beginning of the FOLL_PIN support in commit |
||
|
Matthew Wilcox (Oracle)
|
6c357848b4 |
mm: replace hpage_nr_pages with thp_nr_pages
The thp prefix is more frequently used than hpage and we should be consistent between the various functions. [akpm@linux-foundation.org: fix mm/migrate.c] Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Link: http://lkml.kernel.org/r/20200629151959.15779-6-willy@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Peter Xu
|
64019a2e46 |
mm/gup: remove task_struct pointer for all gup code
After the cleanup of page fault accounting, gup does not need to pass task_struct around any more. Remove that parameter in the whole gup stack. Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Link: http://lkml.kernel.org/r/20200707225021.200906-26-peterx@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Peter Xu
|
a2beb5f1ef |
mm: clean up the last pieces of page fault accountings
Here're the last pieces of page fault accounting that were still done
outside handle_mm_fault() where we still have regs==NULL when calling
handle_mm_fault():
arch/powerpc/mm/copro_fault.c: copro_handle_mm_fault
arch/sparc/mm/fault_32.c: force_user_fault
arch/um/kernel/trap.c: handle_page_fault
mm/gup.c: faultin_page
fixup_user_fault
mm/hmm.c: hmm_vma_fault
mm/ksm.c: break_ksm
Some of them has the issue of duplicated accounting for page fault
retries. Some of them didn't do the accounting at all.
This patch cleans all these up by letting handle_mm_fault() to do per-task
page fault accounting even if regs==NULL (though we'll still skip the perf
event accountings). With that, we can safely remove all the outliers now.
There's another functional change in that now we account the page faults
to the caller of gup, rather than the task_struct that passed into the gup
code. More information of this can be found at [1].
After this patch, below things should never be touched again outside
handle_mm_fault():
- task_struct.[maj|min]_flt
- PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]
[1] https://lore.kernel.org/lkml/CAHk-=wj_V2Tps2QrMn20_W0OJF9xqNh52XSGA42s-ZJ8Y+GyKw@mail.gmail.com/
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200707225021.200906-25-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Peter Xu
|
bce617edec |
mm: do page fault accounting in handle_mm_fault
Patch series "mm: Page fault accounting cleanups", v5.
This is v5 of the pf accounting cleanup series. It originates from Gerald
Schaefer's report on an issue a week ago regarding to incorrect page fault
accountings for retried page fault after commit
|
||
Joonsoo Kim
|
ed03d92458 |
mm/gup: use a standard migration target allocation callback
There is a well-defined migration target allocation callback. Use it. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Roman Gushchin <guro@fb.com> Link: http://lkml.kernel.org/r/1596180906-8442-3-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Joonsoo Kim
|
bbe88753bd |
mm/hugetlb: make hugetlb migration callback CMA aware
new_non_cma_page() in gup.c requires to allocate the new page that is not on the CMA area. new_non_cma_page() implements it by using allocation scope APIs. However, there is a work-around for hugetlb. Normal hugetlb page allocation API for migration is alloc_huge_page_nodemask(). It consists of two steps. First is dequeing from the pool. Second is, if there is no available page on the queue, allocating by using the page allocator. new_non_cma_page() can't use this API since first step (deque) isn't aware of scope API to exclude CMA area. So, new_non_cma_page() exports hugetlb internal function for the second step, alloc_migrate_huge_page(), to global scope and uses it directly. This is suboptimal since hugetlb pages on the queue cannot be utilized. This patch tries to fix this situation by making the deque function on hugetlb CMA aware. In the deque function, CMA memory is skipped if PF_MEMALLOC_NOCMA flag is found. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Roman Gushchin <guro@fb.com> Link: http://lkml.kernel.org/r/1596180906-8442-2-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Joonsoo Kim
|
41b4dc14ee |
mm/gup: restrict CMA region by using allocation scope API
We have well defined scope API to exclude CMA region. Use it rather than
manipulating gfp_mask manually. With this change, we can now restore
__GFP_MOVABLE for gfp_mask like as usual migration target allocation. It
would result in that the ZONE_MOVABLE is also searched by page allocator.
For hugetlb, gfp_mask is redefined since it has a regular allocation mask
filter for migration target. __GPF_NOWARN is added to hugetlb gfp_mask
filter since a new user for gfp_mask filter, gup, want to be silent when
allocation fails.
Note that this can be considered as a fix for the commit
|
||
Tang Yizhou
|
0a36f7f85e |
mm/gup.c: fix the comment of return value for populate_vma_page_range()
The return value of populate_vma_page_range() is consistent with __get_user_pages(), and so is the function comment of return value. Signed-off-by: Tang Yizhou <tangyizhou@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: http://lkml.kernel.org/r/20200720034303.29920-1-tangyizhou@huawei.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Christophe Leroy
|
481e980a7c |
mm: Allow arches to provide ptep_get()
Since commit |
||
|
Christophe Leroy
|
55ca22633a |
mm/gup: Use huge_ptep_get() in gup_hugepte()
gup_hugepte() reads hugepage table entries, it can't read
them directly, huge_ptep_get() must be used.
Fixes:
|
||
Michel Lespinasse
|
c1e8d7c6a7 |
mmap locking API: convert mmap_sem comments
Convert comments that reference mmap_sem to reference mmap_lock instead. [akpm@linux-foundation.org: fix up linux-next leftovers] [akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil] [akpm@linux-foundation.org: more linux-next fixups, per Michel] Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Michel Lespinasse
|
3e4e28c5a8 |
mmap locking API: convert mmap_sem API comments
Convert comments that reference old mmap_sem APIs to reference corresponding new mmap locking APIs instead. Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-12-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Michel Lespinasse
|
da1c55f1b2 |
mmap locking API: rename mmap_sem to mmap_lock
Rename the mmap_sem field to mmap_lock. Any new uses of this lock should now go through the new mmap locking api. The mmap_lock is still implemented as a rwsem, though this could change in the future. [akpm@linux-foundation.org: fix it for mm-gup-might_lock_readmmap_sem-in-get_user_pages_fast.patch] Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-11-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Michel Lespinasse
|
42fc541404 |
mmap locking API: add mmap_assert_locked() and mmap_assert_write_locked()
Add new APIs to assert that mmap_sem is held. Using this instead of rwsem_is_locked and lockdep_assert_held[_write] makes the assertions more tolerant of future changes to the lock type. Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-10-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Michel Lespinasse
|
d8ed45c5dc |
mmap locking API: use coccinelle to convert mmap_sem rwsem call sites
This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mike Rapoport
|
e31cf2f4ca |
mm: don't include asm/pgtable.h if linux/mm.h is already included
Patch series "mm: consolidate definitions of page table accessors", v2.
The low level page table accessors (pXY_index(), pXY_offset()) are
duplicated across all architectures and sometimes more than once. For
instance, we have 31 definition of pgd_offset() for 25 supported
architectures.
Most of these definitions are actually identical and typically it boils
down to, e.g.
static inline unsigned long pmd_index(unsigned long address)
{
return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
}
static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}
These definitions can be shared among 90% of the arches provided
XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined.
For architectures that really need a custom version there is always
possibility to override the generic version with the usual ifdefs magic.
These patches introduce include/linux/pgtable.h that replaces
include/asm-generic/pgtable.h and add the definitions of the page table
accessors to the new header.
This patch (of 12):
The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the
functions involving page table manipulations, e.g. pte_alloc() and
pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h>
in the files that include <linux/mm.h>.
The include statements in such cases are remove with a simple loop:
for f in $(git grep -l "include <linux/mm.h>") ; do
sed -i -e '/include <asm\/pgtable.h>/ d' $f
done
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
John Hubbard
|
6a005645ed |
mm/gup: documentation fix for pin_user_pages*() APIs
All of the pin_user_pages*() API calls will cause pages to be dma-pinned. As such, they are all suitable for either DMA, RDMA, and/or Direct IO. The documentation should say so, but it was instead saying that three of the API calls were only suitable for Direct IO. This was discovered when a reviewer wondered why an API call that specifically recommended against Case 2 (DMA/RDMA) was being used in a DMA situation [1]. Fix this by simply deleting those claims. The gup.c comments already refer to the more extensive Documentation/core-api/pin_user_pages.rst, which does have the correct guidance. So let's just write it once, there. [1] https://lore.kernel.org/r/20200529074658.GM30374@kadam Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Acked-by: Souptick Joarder <jrdr.linux@gmail.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Jan Kara <jack@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Link: http://lkml.kernel.org/r/20200529084515.46259-1-jhubbard@nvidia.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
John Hubbard
|
420c2091b6 |
mm/gup: introduce pin_user_pages_locked()
Patch series "mm/gup: introduce pin_user_pages_locked(), use it in frame_vector.c", v2. This adds yet one more pin_user_pages*() variant, and uses that to convert mm/frame_vector.c. With this, along with maybe 20 or 30 other recent patches in various trees, we are close to having the relevant gup call sites converted--with the notable exception of the bio/block layer. This patch (of 2): Introduce pin_user_pages_locked(), which is nearly identical to get_user_pages_locked() except that it sets FOLL_PIN and rejects FOLL_GET. As with other pairs of get_user_pages*() and pin_user_pages() API calls, it's prudent to assert that FOLL_PIN is *not* set in the get_user_pages*() call, so add that as part of this. [jhubbard@nvidia.com: v2] Link: http://lkml.kernel.org/r/20200531234131.770697-2-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Souptick Joarder <jrdr.linux@gmail.com> Link: http://lkml.kernel.org/r/20200531234131.770697-1-jhubbard@nvidia.com Link: http://lkml.kernel.org/r/20200527223243.884385-1-jhubbard@nvidia.com Link: http://lkml.kernel.org/r/20200527223243.884385-2-jhubbard@nvidia.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
Souptick Joarder
|
dadbb612f6 |
mm/gup.c: convert to use get_user_{page|pages}_fast_only()
API __get_user_pages_fast() renamed to get_user_pages_fast_only() to align with pin_user_pages_fast_only(). As part of this we will get rid of write parameter. Instead caller will pass FOLL_WRITE to get_user_pages_fast_only(). This will not change any existing functionality of the API. All the callers are changed to pass FOLL_WRITE. Also introduce get_user_page_fast_only(), and use it in a few places that hard-code nr_pages to 1. Updated the documentation of the API. Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Paul Mackerras <paulus@ozlabs.org> [arch/powerpc/kvm] Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Michal Suchanek <msuchanek@suse.de> Link: http://lkml.kernel.org/r/1590396812-31277-1-git-send-email-jrdr.linux@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Michal Hocko
|
2d3a36a479 |
mm, mempolicy: fix up gup usage in lookup_node
|