The patch titled
Subject: memcg-v1: no need for memcg locking for writeback tracking
has been added to the -mm mm-unstable branch. Its filename is
memcg-v1-no-need-for-memcg-locking-for-writeback-tracking.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/memcg-v1-no-need-for-memcg-locking-for-writeback-tracking.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: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Subject: memcg-v1: no need for memcg locking for writeback tracking
Date: Thu, 24 Oct 2024 18:23:01 -0700
During the era of memcg charge migration, the kernel has to be make
sure that the writeback stat updates do not race with the charge
migration. Otherwise it might update the writeback stats of the wrong
memcg. Now with the memcg charge migration gone, there is no more race
for writeback stat updates and the previous locking can be removed.
Link: https://lkml.kernel.org/r/20241025012304.2473312-5-shakeel.butt@xxxxxxxxx
Signed-off-by: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Reviewed-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Cc: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page-writeback.c | 4 ----
1 file changed, 4 deletions(-)
--- a/mm/page-writeback.c~memcg-v1-no-need-for-memcg-locking-for-writeback-tracking
+++ a/mm/page-writeback.c
@@ -3083,7 +3083,6 @@ bool __folio_end_writeback(struct folio
struct address_space *mapping = folio_mapping(folio);
bool ret;
- folio_memcg_lock(folio);
if (mapping && mapping_use_writeback_tags(mapping)) {
struct inode *inode = mapping->host;
struct backing_dev_info *bdi = inode_to_bdi(inode);
@@ -3114,7 +3113,6 @@ bool __folio_end_writeback(struct folio
lruvec_stat_mod_folio(folio, NR_WRITEBACK, -nr);
zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, -nr);
node_stat_mod_folio(folio, NR_WRITTEN, nr);
- folio_memcg_unlock(folio);
return ret;
}
@@ -3127,7 +3125,6 @@ void __folio_start_writeback(struct foli
VM_BUG_ON_FOLIO(folio_test_writeback(folio), folio);
- folio_memcg_lock(folio);
if (mapping && mapping_use_writeback_tags(mapping)) {
XA_STATE(xas, &mapping->i_pages, folio_index(folio));
struct inode *inode = mapping->host;
@@ -3168,7 +3165,6 @@ void __folio_start_writeback(struct foli
lruvec_stat_mod_folio(folio, NR_WRITEBACK, nr);
zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, nr);
- folio_memcg_unlock(folio);
access_ret = arch_make_folio_accessible(folio);
/*
_
Patches currently in -mm which might be from shakeel.butt@xxxxxxxxx are
mm-optimize-truncation-of-shadow-entries.patch
mm-optimize-invalidation-of-shadow-entries.patch
mm-truncate-reset-xa_has_values-flag-on-each-iteration.patch
memcg-add-tracing-for-memcg-stat-updates.patch
memcg-add-tracing-for-memcg-stat-updates-v2.patch
memcg-v1-fully-deprecate-move_charge_at_immigrate.patch
memcg-v1-remove-charge-move-code.patch
memcg-v1-no-need-for-memcg-locking-for-dirty-tracking.patch
memcg-v1-no-need-for-memcg-locking-for-writeback-tracking.patch
memcg-v1-no-need-for-memcg-locking-for-mglru.patch
memcg-v1-remove-memcg-move-locking-code.patch
