From: Shakeel Butt <shakeelb@google.com> To: Johannes Weiner <hannes@cmpxchg.org>, Michal Hocko <mhocko@kernel.org> Cc: "Michal Koutný" <mkoutny@suse.com>, "Andrew Morton" <akpm@linux-foundation.org>, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Shakeel Butt" <shakeelb@google.com> Subject: [PATCH 2/2] memcg: unify memcg stat flushing Date: Wed, 29 Sep 2021 21:47:11 -0700 [thread overview] Message-ID: <20210930044711.2892660-2-shakeelb@google.com> (raw) In-Reply-To: <20210930044711.2892660-1-shakeelb@google.com> The memcg stats can be flushed in multiple context and potentially in parallel too. For example multiple parallel user space readers for memcg stats will contend on the rstat locks with each other. There is no need for that. We just need one flusher and everyone else can benefit. In addition after aa48e47e3906 ("memcg: infrastructure to flush memcg stats") the kernel periodically flush the memcg stats from the root, so, the other flushers will potentially have much less work to do. Signed-off-by: Shakeel Butt <shakeelb@google.com> --- mm/memcontrol.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 933dde29c67b..688c891448dd 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1425,7 +1425,7 @@ static char *memory_stat_format(struct mem_cgroup *memcg) * * Current memory state: */ - cgroup_rstat_flush(memcg->css.cgroup); + mem_cgroup_flush_stats(); for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { u64 size; @@ -3529,8 +3529,7 @@ static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) unsigned long val; if (mem_cgroup_is_root(memcg)) { - /* mem_cgroup_threshold() calls here from irqsafe context */ - cgroup_rstat_flush_irqsafe(memcg->css.cgroup); + mem_cgroup_flush_stats(); val = memcg_page_state(memcg, NR_FILE_PAGES) + memcg_page_state(memcg, NR_ANON_MAPPED); if (swap) @@ -3911,7 +3910,7 @@ static int memcg_numa_stat_show(struct seq_file *m, void *v) int nid; struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - cgroup_rstat_flush(memcg->css.cgroup); + mem_cgroup_flush_stats(); for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { seq_printf(m, "%s=%lu", stat->name, @@ -3983,7 +3982,7 @@ static int memcg_stat_show(struct seq_file *m, void *v) BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names) != ARRAY_SIZE(memcg1_stats)); - cgroup_rstat_flush(memcg->css.cgroup); + mem_cgroup_flush_stats(); for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { unsigned long nr; @@ -4486,7 +4485,7 @@ void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages, struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); struct mem_cgroup *parent; - cgroup_rstat_flush_irqsafe(memcg->css.cgroup); + mem_cgroup_flush_stats(); *pdirty = memcg_page_state(memcg, NR_FILE_DIRTY); *pwriteback = memcg_page_state(memcg, NR_WRITEBACK); @@ -5354,12 +5353,14 @@ static void mem_cgroup_css_reset(struct cgroup_subsys_state *css) static void __mem_cgroup_flush_stats(void) { - if (!spin_trylock(&stats_flush_lock)) + unsigned long flag; + + if (!spin_trylock_irqsave(&stats_flush_lock, flag)) return; cgroup_rstat_flush_irqsafe(root_mem_cgroup->css.cgroup); atomic_set(&stats_flush_threshold, 0); - spin_unlock(&stats_flush_lock); + spin_unlock_irqrestore(&stats_flush_lock, flag); } void mem_cgroup_flush_stats(void) @@ -6391,7 +6392,7 @@ static int memory_numa_stat_show(struct seq_file *m, void *v) int i; struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - cgroup_rstat_flush(memcg->css.cgroup); + mem_cgroup_flush_stats(); for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { int nid; -- 2.33.0.685.g46640cef36-goog
WARNING: multiple messages have this Message-ID (diff)
From: Shakeel Butt <shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> To: Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>, Michal Hocko <mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> Cc: "Michal Koutný" <mkoutny-IBi9RG/b67k@public.gmane.org>, "Andrew Morton" <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "Shakeel Butt" <shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> Subject: [PATCH 2/2] memcg: unify memcg stat flushing Date: Wed, 29 Sep 2021 21:47:11 -0700 [thread overview] Message-ID: <20210930044711.2892660-2-shakeelb@google.com> (raw) In-Reply-To: <20210930044711.2892660-1-shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> The memcg stats can be flushed in multiple context and potentially in parallel too. For example multiple parallel user space readers for memcg stats will contend on the rstat locks with each other. There is no need for that. We just need one flusher and everyone else can benefit. In addition after aa48e47e3906 ("memcg: infrastructure to flush memcg stats") the kernel periodically flush the memcg stats from the root, so, the other flushers will potentially have much less work to do. Signed-off-by: Shakeel Butt <shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> --- mm/memcontrol.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 933dde29c67b..688c891448dd 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1425,7 +1425,7 @@ static char *memory_stat_format(struct mem_cgroup *memcg) * * Current memory state: */ - cgroup_rstat_flush(memcg->css.cgroup); + mem_cgroup_flush_stats(); for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { u64 size; @@ -3529,8 +3529,7 @@ static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) unsigned long val; if (mem_cgroup_is_root(memcg)) { - /* mem_cgroup_threshold() calls here from irqsafe context */ - cgroup_rstat_flush_irqsafe(memcg->css.cgroup); + mem_cgroup_flush_stats(); val = memcg_page_state(memcg, NR_FILE_PAGES) + memcg_page_state(memcg, NR_ANON_MAPPED); if (swap) @@ -3911,7 +3910,7 @@ static int memcg_numa_stat_show(struct seq_file *m, void *v) int nid; struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - cgroup_rstat_flush(memcg->css.cgroup); + mem_cgroup_flush_stats(); for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { seq_printf(m, "%s=%lu", stat->name, @@ -3983,7 +3982,7 @@ static int memcg_stat_show(struct seq_file *m, void *v) BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names) != ARRAY_SIZE(memcg1_stats)); - cgroup_rstat_flush(memcg->css.cgroup); + mem_cgroup_flush_stats(); for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { unsigned long nr; @@ -4486,7 +4485,7 @@ void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages, struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); struct mem_cgroup *parent; - cgroup_rstat_flush_irqsafe(memcg->css.cgroup); + mem_cgroup_flush_stats(); *pdirty = memcg_page_state(memcg, NR_FILE_DIRTY); *pwriteback = memcg_page_state(memcg, NR_WRITEBACK); @@ -5354,12 +5353,14 @@ static void mem_cgroup_css_reset(struct cgroup_subsys_state *css) static void __mem_cgroup_flush_stats(void) { - if (!spin_trylock(&stats_flush_lock)) + unsigned long flag; + + if (!spin_trylock_irqsave(&stats_flush_lock, flag)) return; cgroup_rstat_flush_irqsafe(root_mem_cgroup->css.cgroup); atomic_set(&stats_flush_threshold, 0); - spin_unlock(&stats_flush_lock); + spin_unlock_irqrestore(&stats_flush_lock, flag); } void mem_cgroup_flush_stats(void) @@ -6391,7 +6392,7 @@ static int memory_numa_stat_show(struct seq_file *m, void *v) int i; struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - cgroup_rstat_flush(memcg->css.cgroup); + mem_cgroup_flush_stats(); for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { int nid; -- 2.33.0.685.g46640cef36-goog
next prev parent reply other threads:[~2021-09-30 4:47 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-09-30 4:47 [PATCH 1/2] memcg: flush stats only if updated Shakeel Butt 2021-09-30 4:47 ` Shakeel Butt 2021-09-30 4:47 ` Shakeel Butt [this message] 2021-09-30 4:47 ` [PATCH 2/2] memcg: unify memcg stat flushing Shakeel Butt 2021-10-01 14:29 ` Johannes Weiner 2021-10-01 14:29 ` Johannes Weiner 2021-10-01 14:28 ` [PATCH 1/2] memcg: flush stats only if updated Johannes Weiner 2021-10-01 14:28 ` Johannes Weiner 2021-10-01 14:41 ` Shakeel Butt 2021-10-01 14:41 ` Shakeel Butt
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