linux/mm
Joel Fernandes (Google) 2c91bd4a4e mm: speed up mremap by 20x on large regions
Android needs to mremap large regions of memory during memory management
related operations.  The mremap system call can be really slow if THP is
not enabled.  The bottleneck is move_page_tables, which is copying each
pte at a time, and can be really slow across a large map.  Turning on
THP may not be a viable option, and is not for us.  This patch speeds up
the performance for non-THP system by copying at the PMD level when
possible.

The speedup is an order of magnitude on x86 (~20x).  On a 1GB mremap,
the mremap completion times drops from 3.4-3.6 milliseconds to 144-160
microseconds.

Before:
Total mremap time for 1GB data: 3521942 nanoseconds.
Total mremap time for 1GB data: 3449229 nanoseconds.
Total mremap time for 1GB data: 3488230 nanoseconds.

After:
Total mremap time for 1GB data: 150279 nanoseconds.
Total mremap time for 1GB data: 144665 nanoseconds.
Total mremap time for 1GB data: 158708 nanoseconds.

If THP is enabled the optimization is mostly skipped except in certain
situations.

[joel@joelfernandes.org: fix 'move_normal_pmd' unused function warning]
  Link: http://lkml.kernel.org/r/20181108224457.GB209347@google.com
Link: http://lkml.kernel.org/r/20181108181201.88826-3-joelaf@google.com
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:48 -08:00
..
kasan mm: treewide: remove unused address argument from pte_alloc functions 2019-01-04 13:13:47 -08:00
backing-dev.c blkcg: delay blkg destruction until after writeback has finished 2018-08-31 14:48:56 -06:00
balloon_compaction.c virtio_balloon: fix deadlock on OOM 2017-11-14 23:57:38 +02:00
cleancache.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
cma_debug.c mm/cma: remove unsupported gfp_mask parameter from cma_alloc() 2018-08-17 16:20:32 -07:00
cma.c kasan, mm, arm64: tag non slab memory allocated via pagealloc 2018-12-28 12:11:44 -08:00
cma.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compaction.c mm: move zone watermark accesses behind an accessor 2018-12-28 12:11:48 -08:00
debug_page_ref.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
debug.c mm/debug.c: make "migrate_reason_names[]" const char * 2018-12-28 12:11:48 -08:00
dmapool.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
early_ioremap.c mm/early_ioremap: Fix boot hang with earlyprintk=efi,keep 2017-12-11 14:54:44 +01:00
fadvise.c vfs: implement readahead(2) using POSIX_FADV_WILLNEED 2018-08-30 20:01:32 +02:00
failslab.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
filemap.c mm, fault_around: do not take a reference to a locked page 2018-12-28 12:11:51 -08:00
frame_vector.c mm/frame_vector.c: release a semaphore in 'get_vaddr_frames()' 2017-12-14 16:00:48 -08:00
frontswap.c mm: use octal not symbolic permissions 2018-06-15 07:55:25 +09:00
gup_benchmark.c mm/gup_benchmark.c: prevent integer overflow in ioctl 2018-10-31 08:54:12 -07:00
gup.c mm/gup: finish consolidating error handling 2018-11-30 14:56:13 -08:00
highmem.c mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00
hmm.c mm/hmm: fix memremap.h, move dev_page_fault_t callback to hmm 2018-12-28 12:11:52 -08:00
huge_memory.c mm: treewide: remove unused address argument from pte_alloc functions 2019-01-04 13:13:47 -08:00
hugetlb_cgroup.c mm: rename page_counter's count/limit into usage/max 2018-06-07 17:34:35 -07:00
hugetlb.c hugetlbfs: Use i_mmap_rwsem to fix page fault/truncate race 2018-12-28 12:11:52 -08:00
hwpoison-inject.c mm/memory_failure: Remove unused trapno from memory_failure 2018-01-23 12:17:42 -06:00
init-mm.c mm: Allocate the mm_cpumask (mm->cpu_bitmap[]) dynamically based on nr_cpu_ids 2018-07-17 09:35:30 +02:00
internal.h mm: use alloc_flags to record if kswapd can wake 2018-12-28 12:11:48 -08:00
interval_tree.c mm/interval_tree.c: use vma_pages() helper 2018-01-31 17:18:37 -08:00
Kconfig ksm: replace jhash2 with xxhash 2018-12-28 12:11:46 -08:00
Kconfig.debug mm: clarify CONFIG_PAGE_POISONING and usage 2018-08-22 10:52:44 -07:00
khugepaged.c mm/mmu_notifier: use structure for invalidate_range_start/end calls v2 2018-12-28 12:11:50 -08:00
kmemleak-test.c
kmemleak.c kmemleak: add config to select auto scan 2018-12-28 12:11:51 -08:00
ksm.c ksm: react on changing "sleep_millisecs" parameter faster 2018-12-28 12:11:51 -08:00
list_lru.c mm/list_lru: introduce list_lru_shrink_walk_irq() 2018-08-17 16:20:32 -07:00
maccess.c x86/fault: BUG() when uaccess helpers fault on kernel addresses 2018-09-03 15:12:09 +02:00
madvise.c mm/mmu_notifier: use structure for invalidate_range_start/end calls v2 2018-12-28 12:11:50 -08:00
Makefile mm: remove nobootmem 2018-10-31 08:54:16 -07:00
memblock.c mm/memblock.c: skip kmemleak for kasan_init() 2018-12-28 12:11:49 -08:00
memcontrol.c memcg, oom: notify on oom killer invocation from the charge path 2018-12-28 12:11:52 -08:00
memfd.c memfd: Convert memfd_tag_pins to XArray 2018-10-21 10:46:41 -04:00
memory_hotplug.c mm, memory_hotplug: deobfuscate migration part of offlining 2018-12-28 12:11:50 -08:00
memory-failure.c hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization 2018-12-28 12:11:51 -08:00
memory.c mm: treewide: remove unused address argument from pte_alloc functions 2019-01-04 13:13:47 -08:00
mempolicy.c Revert "mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask" 2018-12-08 10:26:20 -08:00
mempool.c mm/mempool.c: add missing parameter description 2018-08-22 10:52:44 -07:00
memtest.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
migrate.c mm: treewide: remove unused address argument from pte_alloc functions 2019-01-04 13:13:47 -08:00
mincore.c xarray: Replace exceptional entries 2018-09-29 22:47:49 -04:00
mlock.c dax: remove VM_MIXEDMAP for fsdax and device dax 2018-08-17 16:20:27 -07:00
mm_init.c mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00
mmap.c mm/mmap.c: remove verify_mm_writelocked() 2018-12-28 12:11:47 -08:00
mmu_context.c
mmu_gather.c mm: Replace call_rcu_sched() with call_rcu() 2018-11-27 09:21:46 -08:00
mmu_notifier.c mm/mmu_notifier: use structure for invalidate_range_start/end calls v2 2018-12-28 12:11:50 -08:00
mmzone.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mprotect.c mm/mmu_notifier: use structure for invalidate_range_start/end calls v2 2018-12-28 12:11:50 -08:00
mremap.c mm: speed up mremap by 20x on large regions 2019-01-04 13:13:48 -08:00
msync.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
nommu.c mm/gup: cache dev_pagemap while pinning pages 2018-10-26 16:38:15 -07:00
oom_kill.c mm/mmu_notifier: use structure for invalidate_range_start/end calls v2 2018-12-28 12:11:50 -08:00
page_alloc.c mm/page_alloc.c: allow error injection 2018-12-28 12:11:51 -08:00
page_counter.c memcg: introduce memory.min 2018-06-07 17:34:36 -07:00
page_ext.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
page_idle.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
page_io.c block: don't use un-ordered __set_current_state(TASK_UNINTERRUPTIBLE) 2019-01-02 10:46:03 -08:00
page_isolation.c mm: only report isolation failures when offlining memory 2018-12-28 12:11:46 -08:00
page_owner.c mm/page_owner: clamp read count to PAGE_SIZE 2018-12-28 12:11:46 -08:00
page_poison.c virtio, vhost: fixes, tweaks 2018-11-01 14:42:49 -07:00
page_vma_mapped.c mm/rmap: map_pte() was not handling private ZONE_DEVICE page properly 2018-10-31 08:54:11 -07:00
page-writeback.c mm/page-writeback.c: don't break integrity writeback on ->writepage() error 2018-12-28 12:11:49 -08:00
pagewalk.c mm: kernel-doc: add missing parameter descriptions 2018-04-05 21:36:27 -07:00
percpu-internal.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
percpu-km.c percpu: convert spin_lock_irq to spin_lock_irqsave. 2018-12-18 09:04:08 -08:00
percpu-stats.c treewide: Use array_size() in vmalloc() 2018-06-12 16:19:22 -07:00
percpu-vm.c percpu: allow select gfp to be passed to underlying allocators 2018-02-18 05:33:01 -08:00
percpu.c Merge branch 'for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu 2018-11-01 09:27:57 -07:00
pgtable-generic.c x86/mm: Page size aware flush_tlb_mm_range() 2018-10-09 16:51:11 +02:00
process_vm_access.c mm: docs: add blank lines to silence sphinx "Unexpected indentation" errors 2018-02-06 18:32:48 -08:00
quicklist.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
readahead.c mm/readahead.c: simplify get_next_ra_size() 2018-12-28 12:11:46 -08:00
rmap.c hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization 2018-12-28 12:11:51 -08:00
rodata_test.c mm: fix RODATA_TEST failure "rodata_test: test data was not read only" 2017-10-03 17:54:24 -07:00
shmem.c mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00
slab_common.c A fairly normal cycle for documentation stuff. We have a new 2018-12-29 11:21:49 -08:00
slab.c mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00
slab.h kasan, mm: change hooks signatures 2018-12-28 12:11:43 -08:00
slob.c slab: __GFP_ZERO is incompatible with a constructor 2018-06-07 17:34:34 -07:00
slub.c mm/slub.c: record final state of slub action in deactivate_slab() 2018-12-28 12:11:46 -08:00
sparse-vmemmap.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
sparse.c mm, sparse: pass nid instead of pgdat to sparse_add_one_section() 2018-12-28 12:11:49 -08:00
swap_cgroup.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
swap_slots.c mm, swap, get_swap_pages: use entry_size instead of cluster in parameter 2018-08-22 10:52:44 -07:00
swap_state.c Merge branch 'xarray' of git://git.infradead.org/users/willy/linux-dax 2018-10-28 11:35:40 -07:00
swap.c mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00
swapfile.c mm, swap: fix swapoff with KSM pages 2018-12-28 12:11:52 -08:00
truncate.c mm: cleancache: fix corruption on missed inode invalidation 2018-11-30 14:56:14 -08:00
usercopy.c usercopy: Allow boot cmdline disabling of hardening 2018-07-04 08:04:52 -07:00
userfaultfd.c mm: treewide: remove unused address argument from pte_alloc functions 2019-01-04 13:13:47 -08:00
util.c mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00
vmacache.c mm: get rid of vmacache_flush_all() entirely 2018-09-13 15:18:04 -10:00
vmalloc.c mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00
vmpressure.c mm/vmpressure.c: convert to use match_string() helper 2018-06-07 17:34:36 -07:00
vmscan.c mm: put_and_wait_on_page_locked() while page is migrated 2018-12-28 12:11:48 -08:00
vmstat.c mm: convert zone->managed_pages to atomic variable 2018-12-28 12:11:47 -08:00
workingset.c mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00
z3fold.c z3fold: fix possible reclaim races 2018-11-18 10:15:09 -08:00
zbud.c mm: docs: fix parameter names mismatch 2018-02-06 18:32:48 -08:00
zpool.c mm/zpool.c: zpool_evictable: fix mismatch in parameter name and kernel-doc 2018-02-21 15:35:43 -08:00
zsmalloc.c mm/zsmalloc.c: fix fall-through annotation 2018-10-26 16:26:35 -07:00
zswap.c mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00