The patch titled
Subject: mm: memcg: add a helper for non-unified stats flushing
has been added to the -mm mm-unstable branch. Its filename is
mm-memcg-add-a-helper-for-non-unified-stats-flushing.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-memcg-add-a-helper-for-non-unified-stats-flushing.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: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Subject: mm: memcg: add a helper for non-unified stats flushing
Date: Thu, 31 Aug 2023 16:56:09 +0000
Some contexts flush memcg stats outside of unified flushing, directly
using cgroup_rstat_flush(). Add a helper for non-unified flushing, a
counterpart for do_unified_stats_flush(), and use it in those contexts, as
well as in do_unified_stats_flush() itself.
This abstracts the rstat API and makes it easy to introduce modifications
to either unified or non-unified flushing functions without changing
callers.
No functional change intended.
Link: https://lkml.kernel.org/r/20230831165611.2610118-3-yosryahmed@xxxxxxxxxx
Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Acked-by: Waiman Long <longman@xxxxxxxxxx>
Cc: Ivan Babrou <ivan@xxxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Michal Koutný <mkoutny@xxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Cc: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)
--- a/mm/memcontrol.c~mm-memcg-add-a-helper-for-non-unified-stats-flushing
+++ a/mm/memcontrol.c
@@ -640,6 +640,17 @@ static inline void memcg_rstat_updated(s
}
/*
+ * do_stats_flush - do a flush of the memory cgroup statistics
+ * @memcg: memory cgroup to flush
+ *
+ * Only flushes the subtree of @memcg, does not skip under any conditions.
+ */
+static void do_stats_flush(struct mem_cgroup *memcg)
+{
+ cgroup_rstat_flush(memcg->css.cgroup);
+}
+
+/*
* do_unified_stats_flush - do a unified flush of memory cgroup statistics
*
* A unified flush tries to flush the entire hierarchy, but skips if there is
@@ -656,7 +667,7 @@ static void do_unified_stats_flush(void)
WRITE_ONCE(flush_next_time, jiffies_64 + 2*FLUSH_TIME);
- cgroup_rstat_flush(root_mem_cgroup->css.cgroup);
+ do_stats_flush(root_mem_cgroup);
atomic_set(&stats_flush_threshold, 0);
atomic_set(&stats_unified_flush_ongoing, 0);
@@ -7794,7 +7805,7 @@ bool obj_cgroup_may_zswap(struct obj_cgr
break;
}
- cgroup_rstat_flush(memcg->css.cgroup);
+ do_stats_flush(memcg);
pages = memcg_page_state(memcg, MEMCG_ZSWAP_B) / PAGE_SIZE;
if (pages < max)
continue;
@@ -7859,8 +7870,10 @@ void obj_cgroup_uncharge_zswap(struct ob
static u64 zswap_current_read(struct cgroup_subsys_state *css,
struct cftype *cft)
{
- cgroup_rstat_flush(css->cgroup);
- return memcg_page_state(mem_cgroup_from_css(css), MEMCG_ZSWAP_B);
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+
+ do_stats_flush(memcg);
+ return memcg_page_state(memcg, MEMCG_ZSWAP_B);
}
static int zswap_max_show(struct seq_file *m, void *v)
_
Patches currently in -mm which might be from yosryahmed@xxxxxxxxxx are
mm-memcg-properly-name-and-document-unified-stats-flushing.patch
mm-memcg-add-a-helper-for-non-unified-stats-flushing.patch
mm-memcg-let-non-unified-root-stats-flushes-help-unified-flushes.patch
mm-memcg-use-non-unified-stats-flushing-for-userspace-reads.patch
