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Date: Fri, 27 Jun 2014 10:41:39 +0200
From: Matthias Schniedermeyer <ms@citd.de>
To: =?iso-8859-1?B?THVr4T8=?= Czerner <lczerner@redhat.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>,
        Bernd Schubert <bernd.schubert@itwm.fraunhofer.de>,
        Dave Chinner <david@fromorbit.com>,
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        Maksym Planeta <mcsim.planeta@gmail.com>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sysctl: Add a feature to drop caches selectively
Message-ID: <20140627084139.GA29704@citd.de>
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On 26.06.2014 13:57, Luk?? Czerner wrote:

> > So if the authors want to sell this new interface (in whatever form) to
> > the kernel community, they should start with providing a solid use-case,
> > with some more details, explore alternatives and show how the
> > alternatives do not work for them.
> 
> Yes please, let's see some solid use-case for this.

Personally i would want it to verify files after copying them:
Especially while moving files:
- Copy a file
- <drop cache>
- Verify that it really is correct on stable storage
- Remove original file

Currently i choose either of the 3 ways:
- drop_caches
- umount/mount
- Write more data than memory in machine (Which is only an 
approximnation and you have to verify in the same order the files were 
written, so it is likely that any cache was thrashed in the meantime)

But having a way to selectivly "destory" the cache of a file would make 
this task easier.




-- 

Matthias
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