The patch titled
Subject: mm/mlock: remove lru_lock on TestClearPageMlocked
has been added to the -mm tree. Its filename is
mm-mlock-remove-lru_lock-on-testclearpagemlocked.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-mlock-remove-lru_lock-on-testclearpagemlocked.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-mlock-remove-lru_lock-on-testclearpagemlocked.patch
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From: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>
Subject: mm/mlock: remove lru_lock on TestClearPageMlocked
In the func munlock_vma_page, comments mentained lru_lock needed for
serialization with split_huge_pages. But the page must be PageLocked as
well as pages in split_huge_page series funcs. Thus the PageLocked is
enough to serialize both funcs.
Further more, Hugh Dickins pointed: before splitting in
split_huge_page_to_list, the page was unmap_page() to remove pmd/ptes
which protect the page from munlock. Thus, no needs to guard
__split_huge_page_tail for mlock clean, just keep the lru_lock there for
isolation purpose.
LKP found a preempt issue on __mod_zone_page_state which need change to
mod_zone_page_state. Thanks!
Link: https://lkml.kernel.org/r/1604566549-62481-13-git-send-email-alex.shi@xxxxxxxxxxxxxxxxx
Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>
Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Alexander Duyck <alexander.duyck@xxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: "Chen, Rong A" <rong.a.chen@xxxxxxxxx>
Cc: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Jann Horn <jannh@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
Cc: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mika Penttilä <mika.penttila@xxxxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Cc: Wei Yang <richard.weiyang@xxxxxxxxx>
Cc: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mlock.c | 26 +++++---------------------
1 file changed, 5 insertions(+), 21 deletions(-)
--- a/mm/mlock.c~mm-mlock-remove-lru_lock-on-testclearpagemlocked
+++ a/mm/mlock.c
@@ -187,40 +187,24 @@ static void __munlock_isolation_failed(s
unsigned int munlock_vma_page(struct page *page)
{
int nr_pages;
- pg_data_t *pgdat = page_pgdat(page);
/* For try_to_munlock() and to serialize with page migration */
BUG_ON(!PageLocked(page));
-
VM_BUG_ON_PAGE(PageTail(page), page);
- /*
- * Serialize with any parallel __split_huge_page_refcount() which
- * might otherwise copy PageMlocked to part of the tail pages before
- * we clear it in the head page. It also stabilizes thp_nr_pages().
- */
- spin_lock_irq(&pgdat->lru_lock);
-
if (!TestClearPageMlocked(page)) {
/* Potentially, PTE-mapped THP: do not skip the rest PTEs */
- nr_pages = 1;
- goto unlock_out;
+ return 0;
}
nr_pages = thp_nr_pages(page);
- __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
+ mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
- if (__munlock_isolate_lru_page(page, true)) {
- spin_unlock_irq(&pgdat->lru_lock);
+ if (!isolate_lru_page(page))
__munlock_isolated_page(page);
- goto out;
- }
- __munlock_isolation_failed(page);
-
-unlock_out:
- spin_unlock_irq(&pgdat->lru_lock);
+ else
+ __munlock_isolation_failed(page);
-out:
return nr_pages - 1;
}
_
Patches currently in -mm which might be from alex.shi@xxxxxxxxxxxxxxxxx are
mm-filemap-add-static-for-function-__add_to_page_cache_locked.patch
fs-ntfs-remove-unused-varibles.patch
fs-ntfs-remove-unused-varible-attr_len.patch
mm-memcg-update-page-struct-member-in-comments.patch
mm-thp-move-lru_add_page_tail-func-to-huge_memoryc.patch
mm-thp-use-head-for-head-page-in-lru_add_page_tail.patch
mm-thp-simplify-lru_add_page_tail.patch
mm-thp-narrow-lru-locking.patch
mm-vmscan-remove-unnecessary-lruvec-adding.patch
mm-rmap-stop-store-reordering-issue-on-page-mapping.patch
mm-rmap-stop-store-reordering-issue-on-page-mapping-fix.patch
mm-memcg-add-debug-checking-in-lock_page_memcg.patch
mm-swapc-fold-vm-event-pgrotated-into-pagevec_move_tail_fn.patch
mm-lru-move-lock-into-lru_note_cost.patch
mm-vmscan-remove-lruvec-reget-in-move_pages_to_lru.patch
mm-mlock-remove-lru_lock-on-testclearpagemlocked.patch
mm-mlock-remove-__munlock_isolate_lru_page.patch
mm-lru-introduce-testclearpagelru.patch
mm-compaction-do-page-isolation-first-in-compaction.patch
mm-swapc-serialize-memcg-changes-in-pagevec_lru_move_fn.patch
mm-lru-replace-pgdat-lru_lock-with-lruvec-lock.patch
mm-lru-replace-pgdat-lru_lock-with-lruvec-lock-fix.patch
mm-lru-replace-pgdat-lru_lock-with-lruvec-lock-fix-2.patch
mm-lru-introduce-the-relock_page_lruvec-function-fix.patch
docs-vm-remove-unused-3-items-explanation-for-proc-vmstat.patch
mm-memcg-bail-early-from-swap-accounting-if-memcg-disabled.patch
mm-memcg-warning-on-memcg-after-readahead-page-charged.patch
