From: Jakub Jelinek <jakub@redhat.com>
To: Linus Torvalds <torvalds@transmeta.com>
Cc: Andrea Arcangeli <andrea@suse.de>,
linux-kernel@vger.kernel.org, Alexander Viro <viro@math.psu.edu>
Subject: Re: negative dentries wasting ram
Date: Fri, 24 May 2002 10:53:48 -0400 [thread overview]
Message-ID: <20020524105348.T13411@devserv.devel.redhat.com> (raw)
In-Reply-To: <20020524071657.GI21164@dualathlon.random> <Pine.LNX.4.44.0205240737400.26171-100000@home.transmeta.com>
On Fri, May 24, 2002 at 07:43:32AM -0700, Linus Torvalds wrote:
>
>
> On Fri, 24 May 2002, Andrea Arcangeli wrote:
> >
> > Negative dentries should be only temporary entities, for example between
> > the allocation of the dentry and the create of the inode, they shouldn't
> > be left around waiting the vm to collect them.
>
> Wrong. Negative dentries are very useful for caching negative lookups:
> look at the average startup sequence of any program linked with glibc, and
> depending on your setup you will notice how it tries to open a _lot_ of a
> files that do not exist (the "depending on your setup" comes from the fact
> that it depends on things like how quickly it finds your "locale" setup
> from its locale path - you may have one of the setups that puts it in the
> first location glibc searches etc).
In glibc 2.3 this will be open("/usr/lib/locale/locale-archive", ), so
negative dentries won't be useful for glibc locale handling (that
doesn't mean negative dentries won't be useful for other things, including
exec?p or searching libraries if $LD_LIBRARY_PATH is used).
Jakub
next prev parent reply other threads:[~2002-05-24 14:53 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-05-24 7:16 negative dentries wasting ram Andrea Arcangeli
2002-05-24 8:10 ` Andreas Dilger
2002-05-24 15:36 ` Andrea Arcangeli
2002-05-24 16:12 ` Alexander Viro
2002-05-24 16:21 ` Andrea Arcangeli
2002-05-24 16:24 ` Alexander Viro
2002-05-24 14:43 ` Linus Torvalds
2002-05-24 14:51 ` David S. Miller
2002-05-24 14:53 ` Jakub Jelinek [this message]
2002-05-24 20:44 ` David Schwartz
2002-05-25 17:33 ` Florian Weimer
2002-05-24 15:54 ` Andrea Arcangeli
2002-05-24 16:22 ` Alexander Viro
2002-05-24 16:29 ` Linus Torvalds
2002-05-24 16:39 ` Andrea Arcangeli
2002-05-24 17:04 ` Alexander Viro
2002-05-24 17:06 ` Alexander Viro
2002-05-24 17:55 ` Andrea Arcangeli
2002-05-24 18:00 ` Alexander Viro
2002-05-24 18:58 ` Andrea Arcangeli
2002-05-24 19:04 ` Alexander Viro
2002-05-24 19:43 ` Andrea Arcangeli
2002-05-24 19:55 ` Alexander Viro
2002-05-24 20:36 ` Andrea Arcangeli
2002-05-24 22:14 ` Jan Harkes
2002-05-24 22:31 ` Andrea Arcangeli
2002-05-26 8:06 ` Eric W. Biederman
2002-05-24 17:00 ` Alexander Viro
2002-05-24 18:36 ` Mark Mielke
2002-05-31 8:34 ` Oliver Neukum
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