Re: [PATCH 0/24] make atomic_read() behave consistently across allarchitectures

From: Christoph Lameter
Date: Thu Aug 16 2007 - 14:50:33 EST


On Thu, 16 Aug 2007, Paul Mackerras wrote:

> Herbert Xu writes:
>
> > It doesn't matter. The memory pressure flag is an *advisory*
> > flag. If we get it wrong the worst that'll happen is that we'd
> > waste some time doing work that'll be thrown away.
>
> Ah, so it's the "racy but I don't care because it's only an
> optimization" case. That's fine. Somehow I find it hard to believe
> that all the racy uses of atomic_read in the kernel are like that,
> though. :)

My use of atomic_read in SLUB is like that. Volatile does not magically
sync up reads somehow.

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