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From: Nick Piggin <nickpiggin@yahoo.com.au>
To: Eric Dumazet <dada1@cosmosbay.com>
Subject: Re: [RESEND] [PATCH] VFS: make file->f_pos access atomic on 32bit arch
Date: Wed, 8 Oct 2008 19:48:59 +1100
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Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
       Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>,
       torvalds@linux-foundation.org,
       Andrew Morton <akpm@linux-foundation.org>,
       Andi Kleen <andi@firstfloor.org>, linux-kernel@vger.kernel.org,
       linux-fsdevel@vger.kernel.org,
       "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
       "Theodore Ts'o" <tytso@mit.edu>
References: <6.0.0.20.2.20081007140438.0580f110@172.19.0.2> <1223448711.1378.16.camel@lappy.programming.kicks-ass.net> <48EC7003.4040108@cosmosbay.com>
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On Wednesday 08 October 2008 19:32, Eric Dumazet wrote:

> A far more interesting problem is the "tail -f logfile" problem that raised
> recently in lkml, when file is NFS mounted, where reader can get nul
> bytes... (Subject : blocks of zeros (NULLs) in NFS files in kernels >=
> 2.6.20 )

Not so interesting outside NFS, AFAIKS? It's just a matter of what
semantics NFS chooses to implement... I guess stronger semantics
will tend to be more costly, all else being equal, probably the
reason why they do it that way.

That behaviour does seem a bit surprising, though.
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