Re: [PATCH 09/18] fs: rework icount to be a locked variable

From: Chris Mason
Date: Fri Oct 08 2010 - 09:18:45 EST


On Fri, Oct 08, 2010 at 10:17:14AM +0200, Christoph Hellwig wrote:
> On Fri, Oct 08, 2010 at 06:50:01PM +1100, Dave Chinner wrote:
> > > There's no need to lock a normal 32-bit variable for readers.
> >
> > Ok, but will need a memory barrier instead?
>
> Isn't spin_unlock supposed to be one? I'll need some of the locking
> experts to shime in.

Not really a locking expert, but the locking operations are supposed to
have an implicit barrier.

-chris

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