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From: Andrew Morton <akpm@digeo.com>
To: David Woodhouse <dwmw2@infradead.org>
Cc: Eli Carter <eli.carter@inet.com>, linux-fsdevel@vger.kernel.org
Subject: Re: File perforation.
Date: Wed, 08 Jan 2003 17:22:59 -0800	[thread overview]
Message-ID: <3E1CCEF3.3409DCED@digeo.com> (raw)
In-Reply-To: 23586.1042067699@passion.cambridge.redhat.com

David Woodhouse wrote:
> 
> I was dubious about adding a check for all zeroes before
> falling back to zlib, since it'll slow down the common case where we write
> non-zero data.

I suggest you bench this first.  As a prototype, just add some code to
touch the data and see how much difference it makes.  Quite possibly
not much - view it as a fancy cache preload.   Plus for real data,
it'll bale out after the first byte...

A full holepunch()/perforate() thing is, as Dave points out, a trickier
version of truncate.  It's quite a hassle for not a lot of gain on
the block filesystems.

  reply	other threads:[~2003-01-09  1:23 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-01-08 22:06 File perforation David Woodhouse
2003-01-08 22:28 ` Eli Carter
2003-01-08 22:34   ` David Woodhouse
2003-01-08 22:56     ` Eli Carter
2003-01-08 23:14       ` David Woodhouse
2003-01-09  1:22         ` Andrew Morton [this message]
2003-01-09  3:23           ` Andreas Dilger
2003-01-08 23:17     ` Steven Whitehouse
2003-01-08 23:16       ` David Woodhouse
2003-01-08 23:36         ` Steven Whitehouse
2003-01-08 23:25           ` David Woodhouse
2003-01-10  1:39         ` Bryan Henderson
2003-01-08 22:45 ` Dave Kleikamp
2003-01-08 22:55 ` Matthew Wilcox
2003-01-08 23:02   ` David Woodhouse
2003-01-11  9:47   ` Christoph Hellwig
2003-01-10  1:34 ` Bryan Henderson
  -- strict thread matches above, loose matches on Subject: below --
2003-01-10 22:24 Steven French
2003-01-11  1:46 ` Bryan Henderson
2003-01-13  3:52 Steven French

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