linux-kernel - Re: [RFC][PATCH] sched: might_sleep(): do rate-limiting before sanity checks

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Message-ID: <558B7746.9010605@sr71.net>
Date:	Wed, 24 Jun 2015 20:36:38 -0700
From:	Dave Hansen <dave@...1.net>
To:	unlisted-recipients:; (no To-header on input)
CC:	mingo@...hat.com, peterz@...radead.org,
	linux-kernel@...r.kernel.org, dave.hansen@...ux.intel.com
Subject: Re: [RFC][PATCH] sched: might_sleep(): do rate-limiting before sanity
 checks

On 06/24/2015 05:03 PM, Dave Hansen wrote:
> In any case, we ratelimit might_sleep() checks anyway.  But, we
> do the ratelimiting *after* we check the other conditions for
> might_sleep() including the (costly) irqs_disabled() call.

Thinking about this a bit more, this patch is wrong.

This only does a _check_ once per jiffy instead of just one warning per
jiffy, which is totally bogus.

I would be interested, though, if anybody has any ideas about speeding
up the irqs_disabled() checking.
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