Date: Sat, 31 Jan 2009 06:55:08 +0100
From: Andi Kleen <andi@firstfloor.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>, roger.larsson@e-gatan.se,
       linux-kernel@vger.kernel.org, mingo@elte.hu, rml@tech9.net,
       pavel@ucw.cz, netdev@vger.kernel.org
Subject: Re: PROBLEM: in_atomic() misuse all over the place
Message-ID: <20090131055508.GD18453@one.firstfloor.org>
References: <200901280010.37633.roger.larsson@e-gatan.se> <87pri7k4id.fsf@basil.nowhere.org> <20090130160316.7e53ef99.akpm@linux-foundation.org>
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> There's a bit of a problem here.  If someone accidentally uses
> gfp_any() inside a spinlock, it will do a sleeping allocation on
> non-preempt kernels and will do an atomic allocation on preemptible
> kernels, so we won't get to see the warning which would allow us to fix
> the bug.

Yes exporting the function to drivers is dangerous I agree because
it's easy to abuse.

> Would using irq_count() work?  If so, that would fix this up.

There's nothing that works reliably to detect spinlocks on non
preempt kernels.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only.
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