From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [patch] rt: res_counter fix, v2
Date: Thu, 12 Feb 2009 18:29:09 +0100
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Cc: Ingo Molnar <mingo@elte.hu>,
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On Thu, 2009-02-12 at 22:28 +0530, Balbir Singh wrote:

> > _nort() will just turn them into NOPs in essence.
> > 
> > The question is, are these local IRQ flags manipulations really needed
> > in this code, and if yes, why?
> 
> We needed the local IRQ flags, since these counters are updated from
> page fault context and from reclaim context with lru_lock held with
> IRQ's disabled. I've been thinking about replacing the spin lock with
> seq lock, but have not gotten to it yet.

Ah, in that case we can get away with _nort I think, as both those
contexts are preemptable on -rt.