The patch titled
Subject: mm-drop-oom-code-from-exit_mmap-fix-fix
has been added to the -mm mm-unstable branch. Its filename is
mm-drop-oom-code-from-exit_mmap-fix-fix.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-drop-oom-code-from-exit_mmap-fix-fix.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Subject: mm-drop-oom-code-from-exit_mmap-fix-fix
Date: Wed Jun 1 03:17:52 PM PDT 2022
restore Suren's mmap_read_lock() optimization
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Liam Howlett <liam.howlett@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/mm/mmap.c~mm-drop-oom-code-from-exit_mmap-fix-fix
+++ a/mm/mmap.c
@@ -3171,13 +3171,13 @@ void exit_mmap(struct mm_struct *mm)
/* mm's last user has gone, and its about to be pulled down */
mmu_notifier_release(mm);
- mmap_write_lock(mm);
+ mmap_read_lock(mm);
arch_exit_mmap(mm);
vma = mas_find(&mas, ULONG_MAX);
if (!vma) {
/* Can happen if dup_mmap() received an OOM */
- mmap_write_unlock(mm);
+ mmap_read_unlock(mm);
return;
}
@@ -3187,6 +3187,7 @@ void exit_mmap(struct mm_struct *mm)
/* update_hiwater_rss(mm) here? but nobody should be looking */
/* Use ULONG_MAX here to ensure all VMAs in the mm are unmapped */
unmap_vmas(&tlb, &mm->mm_mt, vma, 0, ULONG_MAX);
+ mmap_read_unlock(mm);
/*
* Set MMF_OOM_SKIP to hide this task from the oom killer/reaper
@@ -3194,6 +3195,7 @@ void exit_mmap(struct mm_struct *mm)
* mm_is_oom_victim because setting a bit unconditionally is cheaper.
*/
set_bit(MMF_OOM_SKIP, &mm->flags);
+ mmap_write_unlock(mm);
free_pgtables(&tlb, &mm->mm_mt, vma, FIRST_USER_ADDRESS,
USER_PGTABLES_CEILING);
tlb_finish_mmu(&tlb);
_
Patches currently in -mm which might be from akpm@xxxxxxxxxxxxxxxxxxxx are
mm-oom_killc-fix-vm_oom_kill_table-ifdeffery.patch
mm-page_alloc-remotely-drain-per-cpu-lists-checkpatch-fixes.patch
mm-start-tracking-vmas-with-maple-tree-fix.patch
damon-convert-__damon_va_three_regions-to-use-the-vma-iterator-fix.patch
mm-mmap-use-advanced-maple-tree-api-for-mmap_region-fix-checkpatch-fixes.patch
mm-remove-the-vma-linked-list-fix-fix.patch
mm-handling-non-lru-pages-returned-by-vm_normal_pages-fix.patch
mm-introduce-clear_highpage_tagged-fix.patch
kasan-fix-zeroing-vmalloc-memory-with-hw_tags-fix.patch
mm-drop-oom-code-from-exit_mmap-fix.patch
mm-drop-oom-code-from-exit_mmap-fix-fix.patch
squashfs-implement-readahead-checkpatch-fixes.patch
