From: Michal Hocko <mhocko@suse.com>
To: Yosry Ahmed <yosryahmed@google.com>
Cc: "Johannes Weiner" <hannes@cmpxchg.org>,
"Shakeel Butt" <shakeelb@google.com>, "Tejun Heo" <tj@kernel.org>,
"Josef Bacik" <josef@toxicpanda.com>,
"Jens Axboe" <axboe@kernel.dk>,
"Zefan Li" <lizefan.x@bytedance.com>,
"Roman Gushchin" <roman.gushchin@linux.dev>,
"Muchun Song" <muchun.song@linux.dev>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Michal Koutný" <mkoutny@suse.com>,
"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
Subject: Re: [PATCH v2 4/9] cgroup: rstat: add WARN_ON_ONCE() if flushing outside task context
Date: Thu, 30 Mar 2023 10:14:59 +0200 [thread overview]
Message-ID: <ZCVFA78lDj2/Uy0C@dhcp22.suse.cz> (raw)
In-Reply-To: <CAJD7tkaKd9Bcb2-e83Q-kzF7G+crr1U+7uqUPBARXWq-LpyKvw@mail.gmail.com>
On Thu 30-03-23 01:06:26, Yosry Ahmed wrote:
[...]
> If we achieve that, do you think it makes sense to add
> WARN_ON_ONCE(irqs_disabled()) instead to prevent future users from
> flushing while disabling irqs or in irq context?
WARN_ON (similar to BUG_ON) will not prevent anybody from doing bad
things. We already have means to shout about sleepable code being
invoked from an atomic context and there is no reason to duplicate that.
As I've said earlier WARN_ON might panic the system in some
configurations (and yes they are used also in production systems - do
not ask me why...). So please be careful about that and use that only
when something really bad (yet recoverable) is going on.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2023-03-30 8:15 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-28 22:16 [PATCH v2 0/9] memcg: make rstat flushing irq and sleep Yosry Ahmed
2023-03-28 22:16 ` [PATCH v2 1/9] cgroup: rename cgroup_rstat_flush_"irqsafe" to "atomic" Yosry Ahmed
2023-03-28 22:16 ` [PATCH v2 2/9] memcg: rename mem_cgroup_flush_stats_"delayed" to "ratelimited" Yosry Ahmed
2023-03-29 11:56 ` Michal Hocko
2023-03-28 22:16 ` [PATCH v2 3/9] memcg: do not flush stats in irq context Yosry Ahmed
2023-03-29 11:58 ` Michal Hocko
2023-03-28 22:16 ` [PATCH v2 4/9] cgroup: rstat: add WARN_ON_ONCE() if flushing outside task context Yosry Ahmed
2023-03-29 11:22 ` Michal Hocko
2023-03-29 18:41 ` Yosry Ahmed
2023-03-29 19:20 ` Shakeel Butt
2023-03-30 7:06 ` Michal Hocko
2023-03-30 7:13 ` Yosry Ahmed
2023-03-30 7:49 ` Michal Hocko
2023-03-30 8:06 ` Yosry Ahmed
2023-03-30 8:14 ` Michal Hocko [this message]
2023-03-30 8:19 ` Yosry Ahmed
2023-03-30 8:39 ` Michal Hocko
2023-03-30 8:53 ` Yosry Ahmed
2023-03-31 11:02 ` Michal Hocko
2023-03-31 19:03 ` Yosry Ahmed
2023-04-03 8:38 ` Michal Hocko
2023-04-03 20:39 ` Yosry Ahmed
2023-03-28 22:16 ` [PATCH v2 5/9] memcg: replace stats_flush_lock with an atomic Yosry Ahmed
2023-03-28 22:22 ` Shakeel Butt
2023-03-29 15:58 ` Michal Hocko
2023-03-29 18:45 ` Yosry Ahmed
2023-03-28 22:16 ` [PATCH v2 6/9] memcg: sleep during flushing stats in safe contexts Yosry Ahmed
2023-03-30 7:35 ` Michal Hocko
2023-03-28 22:16 ` [PATCH v2 7/9] workingset: memcg: sleep when flushing stats in workingset_refault() Yosry Ahmed
2023-03-30 7:39 ` Michal Hocko
2023-03-30 7:42 ` Yosry Ahmed
2023-03-30 7:50 ` Michal Hocko
2023-03-30 7:55 ` Yosry Ahmed
2023-03-28 22:16 ` [PATCH v2 8/9] vmscan: memcg: sleep when flushing stats during reclaim Yosry Ahmed
2023-03-30 7:40 ` Michal Hocko
2023-03-30 7:44 ` Yosry Ahmed
2023-03-30 7:52 ` Michal Hocko
2023-03-30 7:54 ` Yosry Ahmed
2023-03-28 22:16 ` [PATCH v2 9/9] memcg: do not modify rstat tree for zero updates Yosry Ahmed
2023-03-30 7:43 ` Michal Hocko
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