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: Mon, 3 Apr 2023 10:38:22 +0200 [thread overview]
Message-ID: <ZCqQfuprGreGYwFA@dhcp22.suse.cz> (raw)
In-Reply-To: <CAJD7tka-2vNn25=NdrKQoMf4ntdbWtojY0k4eAa-c9D+v7J=HQ@mail.gmail.com>
On Fri 31-03-23 12:03:47, Yosry Ahmed wrote:
> On Fri, Mar 31, 2023 at 4:02 AM Michal Hocko <mhocko@suse.com> wrote:
> >
> > On Thu 30-03-23 01:53:38, Yosry Ahmed wrote:
> > [...]
> > > Maybe we can add a primitive like might_sleep() for this, just food for thought.
> >
> > I do not think it is the correct to abuse might_sleep if the function
> > itself doesn't sleep. If it does might_sleep is already involved.
>
> Oh, sorry if I wasn't clear, I did not mean to reuse might_sleep() --
> I meant introducing a new similar debug primitive that shouts if irqs
> are disabled.
This is circling back to original concerns about arbitrary decision to
care about IRQs. Is this really any different from spin locks or preempt
disabled critical sections preventing any scheduling and potentially
triggereing soft lockups?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2023-04-03 8:38 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
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 [this message]
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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