From: Peter Zijlstra <peterz@infradead.org>
To: "Ma, Chinang" <chinang.ma@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>,
Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
Mike Galbraith <efault@gmx.de>,
Gregory Haskins <ghaskins@novell.com>,
Steven Rostedt <rostedt@goodmis.org>,
Nick Piggin <nickpiggin@yahoo.com.au>,
"Siddha, Suresh B" <suresh.b.siddha@intel.com>,
"Wilcox, Matthew R" <matthew.r.wilcox@intel.com>,
"Tripathi, Sharad C" <sharad.c.tripathi@intel.com>,
"Chilukuri, Harita" <harita.chilukuri@intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: 2.6.27-rc5 OLTP performance regression
Date: Mon, 08 Sep 2008 20:00:33 +0200 [thread overview]
Message-ID: <1220896833.18239.141.camel@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <BC02C49EEB98354DBA7F5DD76F2A9E8002FE60F751@azsmsx501.amr.corp.intel.com>
On Mon, 2008-09-08 at 10:58 -0700, Ma, Chinang wrote:
> We found the group scheduler in 2.6.27-rc5 has negative performance
> impact on TPC Online Transaction Processing workload. The test was
> conducted on a dual-socket quad-core Xeon server. OLTP workload is
> disk i/o intensive and we have over 200 database shadow processes
> running in the server during this test. Enabling group scheduler
> (CONFIG_GROUP_SCHED=y) reduced performance by 2.0%. Oprofile data
> indicates significant amount of cycles are spent in tg_shares_up().
> This is new regression as we did not find the same issue with 2.6.26
> kernel group scheduler. Is anybody looking into group scheduler
> performance and any idea for reducing the performance impact?
Because the .26 group scheduler wasn't SMP aware. The extra cost comes
from the fact that .27 is.
next parent reply other threads:[~2008-09-08 18:00 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <BC02C49EEB98354DBA7F5DD76F2A9E8002FE60F751@azsmsx501.amr.corp.intel.com>
2008-09-08 18:00 ` Peter Zijlstra [this message]
2008-09-08 18:04 ` Peter Zijlstra
2008-09-09 21:39 ` Ma, Chinang
2008-09-10 12:26 ` Ingo Molnar
2008-09-10 16:14 ` Ma, Chinang
2008-09-10 17:34 ` Ingo Molnar
2008-09-11 0:07 ` Ma, Chinang
2008-09-25 21:04 ` Ma, Chinang
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=1220896833.18239.141.camel@twins.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=chinang.ma@intel.com \
--cc=efault@gmx.de \
--cc=ghaskins@novell.com \
--cc=harita.chilukuri@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=matthew.r.wilcox@intel.com \
--cc=mingo@elte.hu \
--cc=nickpiggin@yahoo.com.au \
--cc=rostedt@goodmis.org \
--cc=sharad.c.tripathi@intel.com \
--cc=suresh.b.siddha@intel.com \
--cc=vatsa@linux.vnet.ibm.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®