From: Avi Kivity <avi@argo.co.il>
To: Josef Sipek <jsipek@fsl.cs.sunysb.edu>
Cc: lkml@pengaru.com, linux-kernel@vger.kernel.org
Subject: Re: rename() contention (BUG?)
Date: Thu, 26 Oct 2006 20:43:34 +0200 [thread overview]
Message-ID: <454101D6.9050004@argo.co.il> (raw)
In-Reply-To: <20061025211341.GB7128@filer.fsl.cs.sunysb.edu>
Josef Sipek wrote:
> On Wed, Oct 25, 2006 at 03:56:34PM -0500, lkml@pengaru.com wrote:
>
>> Hello,
>>
>> I have seen some scalability problems with Maildir-based mail systems running on
>> Linux (debian sarge, 2.6.8), and after much investigation I found a large part
>> of the problem was rename() contention.
>>
>
> Just FYI, around 2.6.15 the i_sem was replace with i_mutex which is much
> better/faster. (And I would strongly suggest you upgrade.) I would actually
> like to know how much the lock contention decresed for your case.
>
The changes make the mutex more efficient, but won't decrease the
contention. It seems that all renames in one filesystem are serialized,
and if the renames require I/O (which is certainly the case with nfs),
rename throughput is severely limited.
--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.
next prev parent reply other threads:[~2006-10-26 18:43 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-10-25 20:56 rename() contention (BUG?) lkml
2006-10-25 21:13 ` Josef Sipek
2006-10-26 18:43 ` Avi Kivity [this message]
2006-10-26 19:22 ` Al Viro
2006-10-26 21:19 ` Avi Kivity
2006-10-26 21:37 ` Al Viro
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=454101D6.9050004@argo.co.il \
--to=avi@argo.co.il \
--cc=jsipek@fsl.cs.sunysb.edu \
--cc=linux-kernel@vger.kernel.org \
--cc=lkml@pengaru.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.