The patch titled
Subject: mm: rmap: remove lock_page_memcg()
has been added to the -mm mm-unstable branch. Its filename is
mm-rmap-remove-lock_page_memcg.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-rmap-remove-lock_page_memcg.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Johannes Weiner <hannes@xxxxxxxxxxx>
Subject: mm: rmap: remove lock_page_memcg()
Date: Tue, 6 Dec 2022 18:13:40 +0100
The previous patch made sure charge moving only touches pages for which
page_mapped() is stable. lock_page_memcg() is no longer needed.
Link: https://lkml.kernel.org/r/20221206171340.139790-3-hannes@xxxxxxxxxxx
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>
Acked-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/rmap.c | 26 ++++++++------------------
1 file changed, 8 insertions(+), 18 deletions(-)
--- a/mm/rmap.c~mm-rmap-remove-lock_page_memcg
+++ a/mm/rmap.c
@@ -1222,9 +1222,6 @@ void page_add_anon_rmap(struct page *pag
bool compound = flags & RMAP_COMPOUND;
bool first = true;
- if (unlikely(PageKsm(page)))
- lock_page_memcg(page);
-
/* Is page being mapped by PTE? Is this its first map to be added? */
if (likely(!compound)) {
first = atomic_inc_and_test(&page->_mapcount);
@@ -1262,15 +1259,14 @@ void page_add_anon_rmap(struct page *pag
if (nr)
__mod_lruvec_page_state(page, NR_ANON_MAPPED, nr);
- if (unlikely(PageKsm(page)))
- unlock_page_memcg(page);
-
- /* address might be in next vma when migration races vma_adjust */
- else if (first)
- __page_set_anon_rmap(page, vma, address,
- !!(flags & RMAP_EXCLUSIVE));
- else
- __page_check_anon_rmap(page, vma, address);
+ if (likely(!PageKsm(page))) {
+ /* address might be in next vma when migration races vma_adjust */
+ if (first)
+ __page_set_anon_rmap(page, vma, address,
+ !!(flags & RMAP_EXCLUSIVE));
+ else
+ __page_check_anon_rmap(page, vma, address);
+ }
mlock_vma_page(page, vma, compound);
}
@@ -1329,7 +1325,6 @@ void page_add_file_rmap(struct page *pag
bool first;
VM_BUG_ON_PAGE(compound && !PageTransHuge(page), page);
- lock_page_memcg(page);
/* Is page being mapped by PTE? Is this its first map to be added? */
if (likely(!compound)) {
@@ -1365,7 +1360,6 @@ void page_add_file_rmap(struct page *pag
NR_SHMEM_PMDMAPPED : NR_FILE_PMDMAPPED, nr_pmdmapped);
if (nr)
__mod_lruvec_page_state(page, NR_FILE_MAPPED, nr);
- unlock_page_memcg(page);
mlock_vma_page(page, vma, compound);
}
@@ -1394,8 +1388,6 @@ void page_remove_rmap(struct page *page,
return;
}
- lock_page_memcg(page);
-
/* Is page being unmapped by PTE? Is this its last map to be removed? */
if (likely(!compound)) {
last = atomic_add_negative(-1, &page->_mapcount);
@@ -1451,8 +1443,6 @@ void page_remove_rmap(struct page *page,
* and remember that it's only reliable while mapped.
*/
- unlock_page_memcg(page);
-
munlock_vma_page(page, vma, compound);
}
_
Patches currently in -mm which might be from hannes@xxxxxxxxxxx are
mm-memcontrol-skip-moving-non-present-pages-that-are-mapped-elsewhere.patch
mm-rmap-remove-lock_page_memcg.patch
mm-memcontrol-deprecate-charge-moving.patch
