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From: Cyrus Massoumi <cyrusm@gmx.net>
To: Nicholas Miell <nmiell@comcast.net>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>,
	"Molnar, Ingo" <mingo@elte.hu>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: Poor PostgreSQL scaling on Linux 2.6.25-rc5 (vs 2.6.22)
Date: Tue, 11 Mar 2008 22:34:08 +0100	[thread overview]
Message-ID: <47D6FAD0.1020608@gmx.net> (raw)
In-Reply-To: <1205269674.12854.16.camel@entropy>

Nicholas Miell wrote:
> 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.)

Did you actually see this? 
http://www.kernel.org/pub/linux/kernel/people/npiggin/sysbench/

FreeBSD does not outperform Linux, it's actually a bit faster according 
to Nick's tests.

I cannot comment on BIND and NSD, but SPECjbb looks pretty close and the 
bad ebizzy performance seems to be an issue with glibc's memory allocator.


greetings
Cyrus


  reply	other threads:[~2008-03-11 21:34 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-11  6:49 Nick Piggin
2008-03-11  7:58 ` Ingo Molnar
2008-03-11  8:28   ` Nick Piggin
2008-03-11  9:59     ` Ingo Molnar
2008-03-11 21:07 ` Nicholas Miell
2008-03-11 21:34   ` Cyrus Massoumi [this message]
2008-03-11 23:12     ` Nicholas Miell
2008-03-11 23:42       ` Nick Piggin
2008-03-11 23:47       ` Stephen Hemminger
2008-03-12  9:00       ` Zhang, Yanmin
     [not found] ` <20080311102538.GA30551@elte.hu>
     [not found]   ` <20080311120230.GA5386@elte.hu>
2008-03-12  1:21     ` Nick Piggin
2008-03-12  7:58       ` Peter Zijlstra
2008-03-17  0:44         ` Nick Piggin
2008-03-17  5:16           ` Ray Lee
2008-03-17  5:21             ` Willy Tarreau
2008-03-17  7:19               ` Nick Piggin
2008-03-17  8:26                 ` Willy Tarreau
2008-03-17  8:54                   ` Nick Piggin
2008-03-17  9:28                     ` Peter Zijlstra
2008-03-17  9:56                       ` Nick Piggin
2008-03-17 10:16                       ` Ingo Molnar
2008-03-17  5:34             ` Nick Piggin
2008-03-14 15:42 Xose Vazquez Perez

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