From: "Jörn Engel" <joern@wohnheim.fh-wedel.de>
To: Rob Landley <rob@landley.net>
Cc: Hua Zhong <hzhong@cisco.com>,
"'Andy Isaacson'" <adi@hexapodia.org>,
linux-kernel@vger.kernel.org
Subject: Re: Is there a "make hole" (truncate in middle) syscall?
Date: Fri, 12 Dec 2003 15:24:59 +0100 [thread overview]
Message-ID: <20031212142459.GG6112@wohnheim.fh-wedel.de> (raw)
In-Reply-To: <20031212135609.GE6112@wohnheim.fh-wedel.de>
On Fri, 12 December 2003 14:56:09 +0100, Jörn Engel wrote:
> On Fri, 12 December 2003 07:39:25 -0600, Rob Landley wrote:
> > On Friday 12 December 2003 06:55, Jörn Engel wrote:
> > >
> > > Yes, the obvious and stupid implementation has a ton of problems.
> > > Most likely the right approach is some sort of background deamon
> > > (garbage collector, defragmenter, journald, whatever you may call it)
> > > that does exacly this even after the fact for the last unchecked
> > > writes. Asyncronous under load, possibly even synchronous when almost
> > > idle.
> >
> > Actually, I'd planned on implementing a cron job that could do it. We're
> > talking a dozen lines of Python code (which can be optimized to only look at
> > files with timestamps since the last time it ran). And doesn't need anything
> > from the kernel but the syscall...
>
> ...and it sucks. Same problem as with updatedb - 99% of all work is
> bogus, but you don't know which 99%, because the one knowing about it,
> the kernel, doesn't tell you a thing.
Actually, updatedb sucks even worse. The database is notoriously
outdated and each run of updatedb has the effect of flushing the
cache. Because of the cache-flushing effect, you cannot even run it
with maximum niceness. Running it still hurts you *afterwards*.
Same goes for you userland daemon without kernel support.
Jörn
--
To recognize individual spam features you have to try to get into the
mind of the spammer, and frankly I want to spend as little time inside
the minds of spammers as possible.
-- Paul Graham
next prev parent reply other threads:[~2003-12-12 14:25 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-12-04 20:32 Is there a "make hole" (truncate in middle) syscall? Rob Landley
2003-12-04 20:55 ` Måns Rullgård
2003-12-04 21:10 ` Szakacsits Szabolcs
2003-12-05 0:02 ` Rob Landley
2003-12-04 22:33 ` Szakacsits Szabolcs
2003-12-05 11:22 ` Helge Hafting
2003-12-05 12:11 ` Måns Rullgård
2003-12-05 22:41 ` Mike Fedyk
2003-12-05 23:25 ` Måns Rullgård
2003-12-05 23:33 ` Szakacsits Szabolcs
2003-12-05 23:25 ` Szakacsits Szabolcs
2003-12-04 21:48 ` Mike Fedyk
2003-12-04 23:59 ` Rob Landley
2003-12-05 22:42 ` Olaf Titz
2003-12-04 22:53 ` Peter Chubb
2003-12-05 1:04 ` Philippe Troin
2003-12-05 2:39 ` Peter Chubb
2003-12-08 4:03 ` bill davidsen
2003-12-04 23:23 ` Andy Isaacson
2003-12-04 23:42 ` Szakacsits Szabolcs
2003-12-05 2:03 ` Mike Fedyk
2003-12-05 7:09 ` Ville Herva
2003-12-05 11:22 ` Anton Altaparmakov
2003-12-05 11:44 ` viro
2003-12-05 14:27 ` Anton Altaparmakov
2003-12-05 21:00 ` sparse file performance (was Re: Is there a "make hole" (truncate in middle) syscall?) Andy Isaacson
2003-12-05 21:12 ` Linus Torvalds
2003-12-08 20:43 ` Andy Isaacson
2003-12-11 5:13 ` Is there a "make hole" (truncate in middle) syscall? Hua Zhong
2003-12-11 6:19 ` Rob Landley
2003-12-11 18:58 ` Andy Isaacson
2003-12-11 19:15 ` Hua Zhong
2003-12-11 19:43 ` Andreas Dilger
2003-12-12 21:37 ` Daniel Phillips
2003-12-11 19:48 ` Jörn Engel
2003-12-11 19:55 ` Hua Zhong
2003-12-11 19:58 ` Andy Isaacson
2003-12-12 12:18 ` Jörn Engel
2003-12-12 15:40 ` Andy Isaacson
2003-12-12 16:03 ` Jörn Engel
2003-12-11 20:32 ` Rob Landley
2003-12-12 12:55 ` Jörn Engel
2003-12-12 13:28 ` Vladimir Saveliev
2003-12-12 13:43 ` Jörn Engel
2003-12-12 13:52 ` Vladimir Saveliev
2003-12-12 14:04 ` Jörn Engel
2003-12-12 13:53 ` Rob Landley
2003-12-12 14:01 ` Vladimir Saveliev
2003-12-12 21:35 ` Rob Landley
2003-12-15 10:00 ` Vladimir Saveliev
2003-12-15 11:52 ` Rob Landley
2003-12-15 13:26 ` Jörn Engel
2003-12-12 13:39 ` Rob Landley
2003-12-12 13:56 ` Jörn Engel
2003-12-12 14:24 ` Jörn Engel [this message]
2003-12-12 21:37 ` Rob Landley
2003-12-15 12:47 ` Jörn Engel
2003-12-16 5:43 ` Rob Landley
2003-12-16 11:05 ` Jörn Engel
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