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Date: Tue, 14 Apr 2009 16:45:33 +0900
From: Tejun Heo <tj@kernel.org>
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Subject: Re: [RFC][PATCH 0/9] File descriptor hot-unplug support
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To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Al Viro <viro@ZenIV.linux.org.uk>, Hugh Dickins <hugh@veritas.com>, Alexey Dobriyan <adobriyan@gmail.com>, Linus Torvalds <torvalds@linux-foundation.org>, Alan Cox <alan@lxorguk.ukuu.org.uk>, Greg Kroah-Hartman <gregkh@suse.de>
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Eric W. Biederman wrote:
> Do you know of a case where we actually have multiple tasks accessing
> a file simultaneously?

I don't have anything at hand but multithread/process server accepting
on the same socket comes to mind.  I don't think it would be a very
rare thing.  If you confine the scope to character devices or sysfs,
it could be quite rare tho.

> I just instrumented up my patch an so far the only case I have found
> are multiple processes closing the same file.  Some weird part of
> bash forking extra processes.

Hmmm...

Thanks.

-- 
tejun

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