The patch titled
Subject: zswap: shrinks zswap pool based on memory pressure (fix)
has been added to the -mm mm-unstable branch. Its filename is
zswap-shrinks-zswap-pool-based-on-memory-pressure-fix.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zswap-shrinks-zswap-pool-based-on-memory-pressure-fix.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: Nhat Pham <nphamcs@xxxxxxxxx>
Subject: zswap: shrinks zswap pool based on memory pressure (fix)
Date: Wed, 6 Dec 2023 11:44:56 -0800
Check shrinker enablement early, and use a less costly stat flushing.
Link: https://lkml.kernel.org/r/20231206194456.3234203-1-nphamcs@xxxxxxxxx
Signed-off-by: Nhat Pham <nphamcs@xxxxxxxxx>
Suggested-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Suggested-by: Chengming Zhou <chengming.zhou@xxxxxxxxx>
Cc: Bagas Sanjaya <bagasdotme@xxxxxxxxx>
Cc: Chris Li <chrisl@xxxxxxxxxx>
Cc: Dan Streetman <ddstreet@xxxxxxxx>
Cc: Domenico Cerasuolo <cerasuolodomenico@xxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Cc: Seth Jennings <sjenning@xxxxxxxxxx>
Cc: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: Vitaly Wool <vitaly.wool@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/zswap.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
--- a/mm/zswap.c~zswap-shrinks-zswap-pool-based-on-memory-pressure-fix
+++ a/mm/zswap.c
@@ -596,13 +596,17 @@ static unsigned long zswap_shrinker_scan
struct zswap_pool *pool = shrinker->private_data;
bool encountered_page_in_swapcache = false;
+ if (!zswap_shrinker_enabled) {
+ sc->nr_scanned = 0;
+ return SHRINK_STOP;
+ }
+
nr_protected =
atomic_long_read(&lruvec->zswap_lruvec_state.nr_zswap_protected);
lru_size = list_lru_shrink_count(&pool->list_lru, sc);
/*
- * Abort if the shrinker is disabled or if we are shrinking into the
- * protected region.
+ * Abort if we are shrinking into the protected region.
*
* This short-circuiting is necessary because if we have too many multiple
* concurrent reclaimers getting the freeable zswap object counts at the
@@ -611,7 +615,7 @@ static unsigned long zswap_shrinker_scan
* objects (i.e the reclaimers will reclaim into the protected area of the
* zswap LRU).
*/
- if (!zswap_shrinker_enabled || nr_protected >= lru_size - sc->nr_to_scan) {
+ if (nr_protected >= lru_size - sc->nr_to_scan) {
sc->nr_scanned = 0;
return SHRINK_STOP;
}
@@ -633,8 +637,11 @@ static unsigned long zswap_shrinker_coun
struct lruvec *lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(sc->nid));
unsigned long nr_backing, nr_stored, nr_freeable, nr_protected;
+ if (!zswap_shrinker_enabled)
+ return 0;
+
#ifdef CONFIG_MEMCG_KMEM
- cgroup_rstat_flush(memcg->css.cgroup);
+ mem_cgroup_flush_stats();
nr_backing = memcg_page_state(memcg, MEMCG_ZSWAP_B) >> PAGE_SHIFT;
nr_stored = memcg_page_state(memcg, MEMCG_ZSWAPPED);
#else
@@ -643,7 +650,7 @@ static unsigned long zswap_shrinker_coun
nr_stored = atomic_read(&pool->nr_stored);
#endif
- if (!zswap_shrinker_enabled || !nr_stored)
+ if (!nr_stored)
return 0;
nr_protected =
_
Patches currently in -mm which might be from nphamcs@xxxxxxxxx are
list_lru-allows-explicit-memcg-and-numa-node-selection.patch
memcontrol-implement-mem_cgroup_tryget_online.patch
zswap-make-shrinking-memcg-aware-fix.patch
zswap-make-shrinking-memcg-aware-fix-2.patch
mm-memcg-add-per-memcg-zswap-writeback-stat-fix.patch
zswap-shrinks-zswap-pool-based-on-memory-pressure.patch
zswap-shrinks-zswap-pool-based-on-memory-pressure-fix.patch
