Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756781AbYCKVIL (ORCPT ); Tue, 11 Mar 2008 17:08:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753024AbYCKVH5 (ORCPT ); Tue, 11 Mar 2008 17:07:57 -0400 Received: from qmta08.emeryville.ca.mail.comcast.net ([76.96.30.80]:44463 "EHLO QMTA08.emeryville.ca.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752158AbYCKVH4 (ORCPT ); Tue, 11 Mar 2008 17:07:56 -0400 X-Authority-Analysis: v=1.0 c=1 a=w_3Tt_6PZGEA:10 a=6I5d2MoRAAAA:8 a=g6u13gMq2JqFQw2tB7kA:9 a=1SGVHmNTQGVQ_JZAwmIA:7 a=c2DFZaH4TijDx0o5EVQUSUdj2ScA:4 a=si9q_4b84H0A:10 a=LY0hPdMaydYA:10 Subject: Re: Poor PostgreSQL scaling on Linux 2.6.25-rc5 (vs 2.6.22) From: Nicholas Miell To: Nick Piggin Cc: "Molnar, Ingo" , LKML In-Reply-To: <200803111749.29143.nickpiggin@yahoo.com.au> References: <200803111749.29143.nickpiggin@yahoo.com.au> Content-Type: text/plain Date: Tue, 11 Mar 2008 14:07:54 -0700 Message-Id: <1205269674.12854.16.camel@entropy> Mime-Version: 1.0 X-Mailer: Evolution 2.12.3 (2.12.3-3.fc8.0.njm.1) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1534 Lines: 36 On Tue, 2008-03-11 at 17:49 +1100, Nick Piggin wrote: > So PostgreSQL performance profile is actually much more interesting. > To my dismay, I found that Linux 2.6.25-rc5 performs really badly > after saturating the runqueues and subsequently increasing threads. > 2.6.22 drops a little bit, but basically settles near the peak > performance. With 2.6.25-rc5, throughput seems to be falling off > linearly with the number of threads. > The FreeBSD folks have a whole host of benchmark results (MySQL, PostgreSQL, BIND, NSD, ebizzy, SPECjbb, etc.) located at http://people.freebsd.org/~kris/scaling/ that demonstrate that the 2.6.23+ scheduler is worse than the 2.6.22 scheduler and both are worse than FreeBSD 7. The interesting thing is that they've been running these tests constantly for years now to demonstrate that their new scheduler hasn't regressed compared to their old scheduler and as a benchmark against the competition (i.e. Linux). Does anybody even do this at all for Linux? (Also, ignoring MySQL because it's a terrible piece of software at least when regarding it's scalability is a bad idea. It's the M in LAMP, it has a huge user base, and FreeBSD manages to outperform Linux with the same unscalable piece of software.) -- Nicholas Miell -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/