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From: Manfred Spraul <manfred@colorfullife.com>
To: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: Re: Scalability requirements for sysv ipc
Date: Fri, 21 Mar 2008 14:33:24 +0100	[thread overview]
Message-ID: <47E3B924.3000304@colorfullife.com> (raw)
In-Reply-To: <47E3ADE3.4030304@bull.net>

Nadia Derbey wrote:
> Manfred Spraul wrote:
>>
>> A microbenchmark on a single-cpu system doesn't help much (except 
>> that 2.6.25 is around factor 2 slower for sysv msg ping-pong between 
>> two tasks compared to the numbers I remember from older kernels....)
>>
>
> If I remember well, at that time I had used ctxbench and I wrote some 
> other small scripts.
> And the results I had were around 2 or 3% slowdown, but I have to 
> confirm that by checking in my archives.
>
Do you have access to multi-core systems? The "best case" for the rcu 
code would be
- 8 or 16 cores
- one instance of ctxbench running on each core, bound to that core.

I'd expect a significant slowdown. The big question is if it matters.

--
    Manfred

  reply	other threads:[~2008-03-21 13:33 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-21  9:41 Scalability requirements for sysv ipc (was: ipc: store ipcs into IDRs) Manfred Spraul
2008-03-21 12:45 ` Nadia Derbey
2008-03-21 13:33   ` Manfred Spraul [this message]
2008-03-21 14:13     ` Scalability requirements for sysv ipc Paul E. McKenney
2008-03-21 16:08       ` Manfred Spraul
2008-03-22  5:43         ` Mike Galbraith
2008-03-22 10:10           ` Manfred Spraul
2008-03-22 11:53             ` Mike Galbraith
2008-03-22 14:22               ` Manfred Spraul
2008-03-22 19:08                 ` Manfred Spraul
2008-03-25 15:50                   ` Mike Galbraith
2008-03-25 16:13                     ` Peter Zijlstra
2008-03-25 18:31                       ` Mike Galbraith
2008-03-26  6:18                       ` Mike Galbraith
2008-03-30 14:12                     ` Scalability requirements for sysv ipc (+namespaces broken with SEM_UNDO) Manfred Spraul
2008-03-30 15:21                       ` David Newall
2008-03-30 17:18                       ` Mike Galbraith
2008-04-04 14:59                         ` Nadia Derbey
2008-04-04 15:03                           ` Nadia Derbey
2008-03-22 19:35                 ` Scalability requirements for sysv ipc Mike Galbraith
2008-03-23  6:38                   ` Manfred Spraul
2008-03-23  7:15                     ` Mike Galbraith
2008-03-23  7:08                   ` Mike Galbraith
2008-03-23  7:20                     ` Mike Galbraith
2008-03-27 22:29           ` Bill Davidsen
2008-03-28  9:49             ` Manfred Spraul
2008-03-25 16:00     ` Nadia Derbey

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