From: "H. Peter Anvin" <hpa@zytor.com>
To: Theodore Tso <tytso@mit.edu>,
Eric Hopper <hopper@omnifarious.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: Question about Reiser4
Date: Mon, 23 Apr 2007 16:53:03 -0700 [thread overview]
Message-ID: <462D46DF.4090802@zytor.com> (raw)
In-Reply-To: <20070423225640.GA1663@thunk.org>
Theodore Tso wrote:
>
> One of the big problems of using a filesystem as a DB is the system
> call overheads. If you use huge numbers of tiny files, then each
> attempt read an atom of information from the DB takes three system
> calls --- an open(), read(), and close(), with all of the overheads in
> terms of dentry and inode cache.
>
Now, to be fair, there are probably a number of cases where
open/lseek/readv/close and open/lseek/writev/close would be worth doing
as a single system call. The big problem as far as I can see involves
EINTR handling; such a system call has serious restartability implications.
Of course, there are Ingo's syslets...
-hpa
next prev parent reply other threads:[~2007-04-23 23:55 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-23 2:00 Question about Reiser4 Eric Hopper
2007-04-23 2:31 ` Lee Revell
2007-04-23 3:56 ` Rik van Riel
2007-04-23 3:56 ` William Heimbigner
2007-04-23 5:47 ` Rik van Riel
2007-04-23 5:57 ` William Heimbigner
2007-04-23 6:07 ` Rik van Riel
2007-04-23 6:14 ` William Heimbigner
2007-04-23 6:20 ` Rik van Riel
2007-04-23 6:42 ` William Heimbigner
2007-04-23 8:04 ` Andrew Morton
2007-04-23 11:31 ` l.genoni
2007-04-23 13:52 ` Eric Hopper
2007-04-23 17:40 ` Andrew Morton
2007-04-23 18:36 ` Miguel Ojeda
2007-04-23 19:05 ` Andi Kleen
2007-04-23 22:56 ` Theodore Tso
2007-04-23 23:53 ` H. Peter Anvin [this message]
2007-04-24 0:14 ` Neil Brown
2007-04-24 0:21 ` H. Peter Anvin
2007-04-24 13:30 ` Jan Engelhardt
2007-04-24 0:19 ` Theodore Tso
2007-04-24 0:31 ` H. Peter Anvin
2007-04-24 1:17 ` Theodore Tso
2007-04-24 11:15 ` Denis Vlasenko
2007-04-25 6:39 ` Eric M. Hopper
2007-04-25 14:45 ` lkml777
2007-04-23 6:14 ` Jeff Chua
[not found] <20070423111939.c876c9cc.akpm@linux-foundation.org>
2007-04-24 14:43 ` Edward Shishkin
2007-04-24 19:39 ` Andi Kleen
2007-04-25 14:35 ` Edward Shishkin
2007-04-25 14:49 ` Jeff Chua
2007-04-25 15:06 ` lkml777
2007-04-25 15:50 ` Jeff Chua
2007-04-26 5:05 ` lkml777
2007-04-26 6:49 ` Jeff Chua
2007-04-26 5:09 ` lkml777
2007-04-26 6:48 ` Jeff Chua
2007-04-26 8:18 ` Jeff Chua
2007-04-27 7:16 ` lkml777
2007-04-26 0:44 ` lkml777
2007-04-25 0:12 ` lkml777
2007-04-25 6:26 ` Eric M. Hopper
2007-04-25 15:03 ` Edward Shishkin
2007-04-26 7:47 ` lkml777
2007-04-26 7:54 ` lkml777
2007-05-02 2:39 ` lkml777
2007-05-02 4:53 ` lkml777
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