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Subject: Re: [PATCH 3/3] nfs: use ->mmap_prepare() to avoid an AB-BA
	deadlock
From: Trond Myklebust <trond.myklebust@fys.uio.no>
To: Nick Piggin <npiggin@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>, linux-kernel@vger.kernel.org,
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On Wed, 2007-11-14 at 23:24 +0100, Nick Piggin wrote:

> mmap()s can be different from read in that the syscall may have little
> relation to when the data gets used. But I guess it's still a best
> effort thing. Fair enough.

Agreed that mmap() is special and very problematic on NFS. However I
can't see how we can improve on the existing models short of some
significant protocol modifications, and so far, nobody has presented the
IETF with a good case for why they need this level of cache consistency.

Cheers
   Trond