From: Yosry Ahmed <yosryahmed@google.com>
To: "Tejun Heo" <tj@kernel.org>, "Josef Bacik" <josef@toxicpanda.com>,
"Jens Axboe" <axboe@kernel.dk>,
"Zefan Li" <lizefan.x@bytedance.com>,
"Johannes Weiner" <hannes@cmpxchg.org>,
"Michal Hocko" <mhocko@kernel.org>,
"Roman Gushchin" <roman.gushchin@linux.dev>,
"Shakeel Butt" <shakeelb@google.com>,
"Muchun Song" <muchun.song@linux.dev>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Michal Koutný" <mkoutny@suse.com>
Cc: Vasily Averin <vasily.averin@linux.dev>,
cgroups@vger.kernel.org, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
bpf@vger.kernel.org, Yosry Ahmed <yosryahmed@google.com>
Subject: [PATCH v1 0/9] memcg: make rstat flushing irq and sleep friendly
Date: Tue, 28 Mar 2023 06:16:29 +0000 [thread overview]
Message-ID: <20230328061638.203420-1-yosryahmed@google.com> (raw)
Currently, all calls to flush memcg stats use the atomic variant for
rstat flushing, cgroup_rstat_flush_irqsafe(), which keeps interrupts
disabled throughout flushing and does not sleep. Flushing stats is an
expensive operation, and we should avoid doing it atomically where
possible. Otherwise, we may end up doing a lot of work without
rescheduling and with interrupts disabled unnecessarily.
Patches 1 and 2 are cleanups requested during reviews of prior versions
of this series.
Patch 3 makes sure we never try to flush from within an irq context, and
patch 4 adds a WARN_ON_ONCE() to make sure we catch any violations.
Patches 5 to 8 introduce separate variants of mem_cgroup_flush_stats()
for atomic and non-atomic flushing, and make sure we only flush the
stats atomically when necessary.
Patch 9 is a slightly tangential optimization that limits the work done
by rstat flushing in some scenarios.
RFC -> v1:
- Dropped patch 1 that attempted to make the global rstat lock a non-irq
lock, will follow up on that separetly (Shakeel).
- Dropped stats_flush_lock entirely, replaced by an atomic (Johannes).
- Renamed cgroup_rstat_flush_irqsafe() to cgroup_rstat_flush_atomic()
instead of removing it (Johannes).
- Added a patch to rename mem_cgroup_flush_stats_delayed() to
mem_cgroup_flush_stats_ratelimited() (Johannes).
- Separate APIs for flushing memcg stats in atomic and non-atomic
contexts instead of a boolean argument (Johannes).
- Added patches 3 & 4 to make sure we never flush from irq context
(Shakeel & Johannes).
Yosry Ahmed (9):
cgroup: rename cgroup_rstat_flush_"irqsafe" to "atomic"
memcg: rename mem_cgroup_flush_stats_"delayed" to "ratelimited"
memcg: do not flush stats in irq context
cgroup: rstat: add WARN_ON_ONCE() if flushing outside task context
memcg: replace stats_flush_lock with an atomic
memcg: sleep during flushing stats in safe contexts
workingset: memcg: sleep when flushing stats in workingset_refault()
vmscan: memcg: sleep when flushing stats during reclaim
memcg: do not modify rstat tree for zero updates
include/linux/cgroup.h | 2 +-
include/linux/memcontrol.h | 9 +++-
kernel/cgroup/rstat.c | 6 ++-
mm/memcontrol.c | 86 ++++++++++++++++++++++++++++++++------
mm/workingset.c | 4 +-
5 files changed, 87 insertions(+), 20 deletions(-)
--
2.40.0.348.gf938b09366-goog
next reply other threads:[~2023-03-28 6:17 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-28 6:16 Yosry Ahmed [this message]
2023-03-28 6:16 ` [PATCH v1 1/9] cgroup: rename cgroup_rstat_flush_"irqsafe" to "atomic" Yosry Ahmed
2023-03-28 13:24 ` Shakeel Butt
2023-03-28 17:42 ` Johannes Weiner
2023-03-28 6:16 ` [PATCH v1 2/9] memcg: rename mem_cgroup_flush_stats_"delayed" to "ratelimited" Yosry Ahmed
2023-03-28 13:25 ` Shakeel Butt
2023-03-28 17:42 ` Johannes Weiner
2023-03-28 6:16 ` [PATCH v1 3/9] memcg: do not flush stats in irq context Yosry Ahmed
2023-03-28 13:26 ` Shakeel Butt
2023-03-28 17:43 ` Johannes Weiner
2023-03-28 6:16 ` [PATCH v1 4/9] cgroup: rstat: add WARN_ON_ONCE() if flushing outside task context Yosry Ahmed
2023-03-28 14:59 ` Shakeel Butt
2023-03-28 17:49 ` Johannes Weiner
2023-03-28 18:59 ` Yosry Ahmed
2023-03-28 22:18 ` Yosry Ahmed
2023-03-28 6:16 ` [PATCH v1 5/9] memcg: replace stats_flush_lock with an atomic Yosry Ahmed
2023-03-28 14:15 ` Shakeel Butt
2023-03-28 18:52 ` Yosry Ahmed
2023-03-28 19:28 ` Shakeel Butt
2023-03-28 19:34 ` Yosry Ahmed
2023-03-28 19:42 ` Yosry Ahmed
2023-03-28 17:53 ` Johannes Weiner
2023-03-28 6:16 ` [PATCH v1 6/9] memcg: sleep during flushing stats in safe contexts Yosry Ahmed
2023-03-28 15:09 ` Shakeel Butt
2023-03-28 18:35 ` Johannes Weiner
2023-03-28 18:45 ` Yosry Ahmed
2023-03-28 19:06 ` Johannes Weiner
2023-03-28 19:26 ` Yosry Ahmed
2023-03-28 6:16 ` [PATCH v1 7/9] workingset: memcg: sleep when flushing stats in workingset_refault() Yosry Ahmed
2023-03-28 15:18 ` Shakeel Butt
2023-03-28 18:47 ` Johannes Weiner
2023-03-28 19:25 ` Yosry Ahmed
2023-03-28 18:43 ` Johannes Weiner
2023-03-28 6:16 ` [PATCH v1 8/9] vmscan: memcg: sleep when flushing stats during reclaim Yosry Ahmed
2023-03-28 15:19 ` Shakeel Butt
2023-03-28 19:01 ` Yosry Ahmed
2023-03-28 19:29 ` Shakeel Butt
2023-03-28 18:49 ` Johannes Weiner
2023-03-28 6:16 ` [PATCH v1 9/9] memcg: do not modify rstat tree for zero updates Yosry Ahmed
2023-03-28 15:20 ` Shakeel Butt
2023-03-28 18:50 ` Johannes Weiner
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