From: Josh Don <joshdon@google.com>
To: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ben Segall <bsegall@google.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Luis Chamberlain <mcgrof@kernel.org>,
Kees Cook <keescook@chromium.org>,
Iurii Zaikin <yzaikin@google.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
linux-fsdevel@vger.kernel.org,
David Rientjes <rientjes@google.com>,
Oleg Rombakh <olegrom@google.com>,
linux-doc@vger.kernel.org, Paul Turner <pjt@google.com>
Subject: Re: [PATCH v2] sched: Warn on long periods of pending need_resched
Date: Thu, 25 Mar 2021 14:58:52 -0700 [thread overview]
Message-ID: <CABk29Nu7rR=_enuU8ecogtwCU3E4ygP0m+nmBH-KqKTRzDCe=A@mail.gmail.com> (raw)
In-Reply-To: <20210324155224.GR15768@suse.de>
> On Wed, Mar 24, 2021 at 01:39:16PM +0000, Mel Gorman wrote:
> I'm not going to NAK because I do not have hard data that shows they must
> exist. However, I won't ACK either because I bet a lot of tasty beverages
> the next time we meet that the following parameters will generate reports
> if removed.
>
> kernel.sched_latency_ns
> kernel.sched_migration_cost_ns
> kernel.sched_min_granularity_ns
> kernel.sched_wakeup_granularity_ns
>
> I know they are altered by tuned for different profiles and some people do
> go the effort to create custom profiles for specific applications. They
> also show up in "Official Benchmarking" such as SPEC CPU 2017 and
> some vendors put a *lot* of effort into SPEC CPU results for bragging
> rights. They show up in technical books and best practice guids for
> applications. Finally they show up in Google when searching for "tuning
> sched_foo". I'm not saying that any of these are even accurate or a good
> idea, just that they show up near the top of the results and they are
> sufficiently popular that they might as well be an ABI.
+1, these seem like sufficiently well-known scheduler tunables, and
not really SCHED_DEBUG.
next prev parent reply other threads:[~2021-03-25 22:02 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-23 3:57 [PATCH v2] sched: Warn on long periods of pending need_resched Josh Don
2021-03-24 9:37 ` Peter Zijlstra
2021-03-24 10:54 ` Peter Zijlstra
2021-03-24 10:55 ` Peter Zijlstra
2021-03-24 11:42 ` Mel Gorman
2021-03-24 12:12 ` Peter Zijlstra
2021-03-24 13:39 ` Mel Gorman
2021-03-24 14:36 ` Peter Zijlstra
2021-03-24 15:52 ` Mel Gorman
2021-03-25 21:58 ` Josh Don [this message]
2021-03-26 8:58 ` Peter Zijlstra
2021-03-24 11:27 ` Mel Gorman
2021-03-25 21:50 ` Josh Don
2021-03-30 22:44 ` Josh Don
2021-04-16 15:04 ` Peter Zijlstra
2021-04-16 21:33 ` Josh Don
2021-04-19 7:52 ` Peter Zijlstra
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