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From: Pavel Machek <pavel@suse.cz>
To: Roger Larsson <roger.larsson@e-gatan.se>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>,
	Robert Love <rml@tech9.net>
Subject: Re: PROBLEM: in_atomic() misuse all over the place
Date: Wed, 4 Feb 2009 17:17:52 +0100	[thread overview]
Message-ID: <20090204161751.GC1218@ucw.cz> (raw)
In-Reply-To: <200901280010.37633.roger.larsson@e-gatan.se>

On Wed 2009-01-28 00:10:37, Roger Larsson wrote:
> (resent, non html)
> 
> [1.] One line summary of the problem:    
> in_atomic() is used to select path of execution, most likely to suppress 
> warning logs when running a preemptive kernel.
> 
> [2.] Full description of the problem/report:
> 
> The problem is that in_atomic() only works on preemptive kernels...
> 
> Result: preemptive kernel warns about a potential deadlock in all kernels,
> developer silence with the help of in_atomic()
> bug remains in SMP/UP kernels...

I guess in_atomic() should be renamed to
unreliable_in_atomic... because it does not really reliably tell you
if you are in atomic section or not.

Or we could negate the logic and call it maybe_kernel_context()?

gfp_any() also needs a better
name. pick_right_gfp_if_you_are_in_kernel_or_softirq_context() sounds
suitable :-).

								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

      parent reply	other threads:[~2009-02-05 15:14 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-01-27 23:10 PROBLEM: in_atomic() misuse all over the place Roger Larsson
2009-01-28  0:12 ` Robert Hancock
2009-01-31 11:45   ` Joerg Roedel
2009-01-28 12:18 ` Andi Kleen
2009-01-31  0:03   ` Andrew Morton
2009-01-31  5:55     ` Andi Kleen
2009-01-31  5:49       ` Andrew Morton
2009-01-31  8:48         ` David Miller
2009-01-31  8:58           ` Andrew Morton
2009-02-04 16:17 ` Pavel Machek [this message]

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