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Matthew Wilcox (Oracle) 5d74b2ab2c mm: make lock_folio_maybe_drop_mmap() VMA lock aware
Patch series "Handle more faults under the VMA lock", v2.

At this point, we're handling the majority of file-backed page faults
under the VMA lock, using the ->map_pages entry point.  This patch set
attempts to expand that for the following siutations:

 - We have to do a read.  This could be because we've hit the point in
   the readahead window where we need to kick off the next readahead,
   or because the page is simply not present in cache.
 - We're handling a write fault.  Most applications don't do I/O by writes
   to shared mmaps for very good reasons, but some do, and it'd be nice
   to not make that slow unnecessarily.
 - We're doing a COW of a private mapping (both PTE already present
   and PTE not-present).  These are two different codepaths and I handle
   both of them in this patch set.

There is no support in this patch set for drivers to mark themselves as
being VMA lock friendly; they could implement the ->map_pages
vm_operation, but if they do, they would be the first.  This is probably
something we want to change at some point in the future, and I've marked
where to make that change in the code.

There is very little performance change in the benchmarks we've run;
mostly because the vast majority of page faults are handled through the
other paths.  I still think this patch series is useful for workloads that
may take these paths more often, and just for cleaning up the fault path
in general (it's now clearer why we have to retry in these cases).


This patch (of 6):

Drop the VMA lock instead of the mmap_lock if that's the one which
is held.

Link: https://lkml.kernel.org/r/20231006195318.4087158-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20231006195318.4087158-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:14 -07:00
arch Merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes. 2023-10-18 14:32:58 -07:00
block block: fix kernel-doc for disk_force_media_change() 2023-09-26 00:43:34 -06:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto crypto: sm2 - Fix crash caused by uninitialized context 2023-09-20 13:10:10 +08:00
Documentation mm/pagemap: add documentation of PAGEMAP_SCAN IOCTL 2023-10-18 14:34:13 -07:00
drivers dax, kmem: calculate abstract distance with general interface 2023-10-16 15:44:39 -07:00
fs fs/proc/task_mmu: add fast paths to get/clear PAGE_IS_WRITTEN flag 2023-10-18 14:34:13 -07:00
include percpu_counter: extend _limited_add() to negative amounts 2023-10-18 14:34:14 -07:00
init workqueue: Changes for v6.6 2023-09-01 16:06:32 -07:00
io_uring io_uring/fs: remove sqe->rw_flags checking from LINKAT 2023-09-29 03:07:09 -06:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel sched/numa, mm: make numa migrate functions to take a folio 2023-10-16 15:44:38 -07:00
lib percpu_counter: extend _limited_add() to negative amounts 2023-10-18 14:34:14 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm: make lock_folio_maybe_drop_mmap() VMA lock aware 2023-10-18 14:34:14 -07:00
net sunrpc: dynamically allocate the sunrpc_cred shrinker 2023-10-04 10:32:24 -07:00
rust Documentation work keeps chugging along; stuff for 6.6 includes: 2023-08-30 20:05:42 -07:00
samples VFIO updates for v6.6-rc1 2023-08-30 20:36:01 -07:00
scripts kbuild: remove stale code for 'source' symlink in packaging scripts 2023-10-01 23:06:06 +09:00
security selinux: fix handling of empty opts in selinux_fs_context_submount() 2023-09-12 17:31:08 -04:00
sound ASoC: Fixes for v6.6 2023-09-20 15:02:16 +02:00
tools radix tree test suite: fix allocation calculation in kmem_cache_alloc_bulk() 2023-10-18 14:34:13 -07:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap mailmap: correct email aliasing for Oleksij Rempel 2023-10-18 12:12:41 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: Ondrej has moved 2023-10-18 12:12:41 -07:00
Makefile Linux 6.6-rc4 2023-10-01 14:15:13 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.