From: Theodore Tso <tytso@mit.edu>
To: linux-ext4@vger.kernel.org
Subject: Re: ext4 unlink performance
Date: Thu, 13 Nov 2008 15:42:40 -0500 [thread overview]
Message-ID: <20081113204240.GF21652@mit.edu> (raw)
In-Reply-To: <20081113191000.GA11516@untroubled.org>
On Thu, Nov 13, 2008 at 01:10:00PM -0600, Bruce Guenter wrote:
> On Thu, Nov 13, 2008 at 12:57:12PM -0600, Bruce Guenter wrote:
> > Ouch. Why is ext4 so much slower than ext3 here,
>
> I forgot to mention one important detail. I started running 'vmstat 5'
> during one of the unlink runs, and noticed that there were intervals of
> 15 or 20 seconds where no blocks were being read or written, and minimal
> CPU was being used. I do not observe the same stalls when using ext3.
Hmm... how very strange. Can you run the command:
ps -eo pid,tid,class,rtprio,ni,pri,psr,pcpu,stat,wchan:16,comm
during one of the quiescent periods, and see what is in the WCHAN
field for the unlink command?
- Ted
next prev parent reply other threads:[~2008-11-13 20:42 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-13 18:57 ext4 unlink performance Bruce Guenter
2008-11-13 19:10 ` Bruce Guenter
2008-11-13 20:42 ` Theodore Tso [this message]
2008-11-14 4:11 ` Bruce Guenter
2008-11-14 14:59 ` Theodore Tso
2008-11-14 15:48 ` Bruce Guenter
2008-11-14 15:54 ` Theodore Tso
2008-11-15 20:44 ` Bruce Guenter
2008-11-15 23:08 ` Eric Sandeen
2008-11-16 0:56 ` Theodore Tso
2008-11-16 3:38 ` Bruce Guenter
2008-11-17 0:43 ` Andreas Dilger
[not found] ` <20081119024021.GA10185@mit.edu>
2008-11-19 18:10 ` Andreas Dilger
2008-11-19 21:18 ` Theodore Tso
2008-11-20 22:49 ` Bruce Guenter
2008-11-13 19:46 ` Theodore Tso
2008-11-13 20:27 ` Bruce Guenter
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