Date: Sun, 30 Dec 2007 14:10:18 +0100
From: Ingo Molnar <mingo@elte.hu>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Andrew Morton <akpm@linux-foundation.org>, trem <tremyfr@yahoo.fr>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: 2.6.24-rc6-mm1
Message-ID: <20071230131018.GC16946@elte.hu>
References: <9DtBq-2jD-3@gated-at.bofh.it> <476EAF98.6040004@yahoo.fr> <20071223121410.0d572e03.akpm@linux-foundation.org> <20071224012524.GA21843@gondor.apana.org.au>
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* Herbert Xu <herbert@gondor.apana.org.au> wrote:

> > Ingo, it's not good that we have cond_resched() definitions 
> > conditionally duplicated in kernel.h - that's increasing the risk of 
> > bugs like this one.
> 
> Actually, why do we even have cond_resched when real preemption is on? 
> It seems to be a waste of space and time.

due to the BKL. cond_resched() in BKL code breaks up BKL latencies.

i dont mind not doing that though - we should increase the pain for BKL 
users, so that subsystems finally get rid of it altogether. 
lock_kernel() use within the kernel is still rampant - there are still 
more than 400 callsites to lock_kernel().

	Ingo
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