Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758117AbYCYQBT (ORCPT ); Tue, 25 Mar 2008 12:01:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755705AbYCYQBF (ORCPT ); Tue, 25 Mar 2008 12:01:05 -0400 Received: from ecfrec.frec.bull.fr ([129.183.4.8]:47420 "EHLO ecfrec.frec.bull.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755427AbYCYQBD (ORCPT ); Tue, 25 Mar 2008 12:01:03 -0400 Message-ID: <47E9219A.2030601@bull.net> Date: Tue, 25 Mar 2008 17:00:26 +0100 From: Nadia Derbey Organization: BULL/DT/OSwR&D/Linux User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040115 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Manfred Spraul Cc: Linux Kernel Mailing List , Andrew Morton , "Paul E. McKenney" Subject: Re: Scalability requirements for sysv ipc References: <47E382DB.70503@colorfullife.com> <47E3ADE3.4030304@bull.net> <47E3B924.3000304@colorfullife.com> In-Reply-To: <47E3B924.3000304@colorfullife.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3203 Lines: 94 Manfred Spraul wrote: > 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 > > Hi, Here is what I could find on my side: ============================================================= lkernel@akt$ cat tst3/res_new/output [root@akt tests]# echo 32768 > /proc/sys/kernel/msgmni [root@akt tests]# ./msgbench_std_dev_plot -n 32768000 msgget iterations in 21.469724 seconds = 1526294/sec 32768000 msgsnd iterations in 18.891328 seconds = 1734583/sec 32768000 msgctl(ipc_stat) iterations in 15.359802 seconds = 2133472/sec 32768000 msgctl(msg_stat) iterations in 15.296114 seconds = 2142260/sec 32768000 msgctl(ipc_rmid) iterations in 32.981277 seconds = 993542/sec AVERAGE STD_DEV MIN MAX GET: 21469.724000 566.024657 19880 23607 SEND: 18891.328000 515.542311 18433 21962 IPC_STAT: 15359.802000 274.918673 15147 17166 MSG_STAT: 15296.114000 155.775508 15138 16790 RM: 32981.277000 675.621060 32141 35433 lkernel@akt$ cat tst3/res_ref/output [root@akt tests]# echo 32768 > /proc/sys/kernel/msgmni [root@akt tests]# ./msgbench_std_dev_plot -r 32768000 msgget iterations in 665.842852 seconds = 49213/sec 32768000 msgsnd iterations in 18.363853 seconds = 1784458/sec 32768000 msgctl(ipc_stat) iterations in 14.609669 seconds = 2243001/sec 32768000 msgctl(msg_stat) iterations in 14.774829 seconds = 2217950/sec 32768000 msgctl(ipc_rmid) iterations in 31.134984 seconds = 1052483/sec AVERAGE STD_DEV MIN MAX GET: 665842.852000 946.697555 654049 672208 SEND: 18363.853000 107.514954 18295 19563 IPC_STAT: 14609.669000 43.100272 14529 14881 MSG_STAT: 14774.829000 97.174924 14516 15436 RM: 31134.984000 444.612055 30521 33523 ================================================================== Unfortunately, I haven't kept the exact kernel release numbers, but the testing method was: res_ref = unpatched kernel res_new = same kernel release with my patches applied. What I'll try to do is to re-run your tests (pmsg and psem) with this method (from my what I saw, the patches applied on a 2.6.23-rc4-mm1), but I can't do it before Thursday. Regards, Nadia -- 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/