Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752622AbaFTRjx (ORCPT ); Fri, 20 Jun 2014 13:39:53 -0400 Received: from mga02.intel.com ([134.134.136.20]:2835 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751064AbaFTRjw (ORCPT ); Fri, 20 Jun 2014 13:39:52 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,515,1400050800"; d="scan'208";a="560823188" Message-ID: <53A471E6.7070209@intel.com> Date: Fri, 20 Jun 2014 10:39:50 -0700 From: Dave Hansen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: paulmck@linux.vnet.ibm.com, Christoph Lameter CC: josh@joshtriplett.org, Andi Kleen , LKML , "Chen, Tim C" Subject: Re: [bisected] pre-3.16 regression on open() scalability References: <20140619180916.GE4904@linux.vnet.ibm.com> <20140619204220.GJ4904@linux.vnet.ibm.com> <20140619213203.GA16747@cloud> <20140619230732.GX4904@linux.vnet.ibm.com> <20140620153839.GB4904@linux.vnet.ibm.com> <20140620163023.GE4904@linux.vnet.ibm.com> In-Reply-To: <20140620163023.GE4904@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/20/2014 09:30 AM, Paul E. McKenney wrote: > On Fri, Jun 20, 2014 at 11:07:13AM -0500, Christoph Lameter wrote: >> On Fri, 20 Jun 2014, Paul E. McKenney wrote: >> >>> And the fraction of the small systems that care that much about latency >>> is also quite small. >> >> This also impacts general performance of course not only latency. >> >>> Of course, if you have performance results that show otherwise, please >>> share them. >> >> We are discussing a performance problem right here. > > We are engaging in a lot of -speculation- about an -alleged- performance > problem. I have posted a fix to the actual performance problem, but the > guy reporting the original report of that problem has not yet reported > the performance of the fix. Which is fine, as I am getting ready to > post an updated fix, and besides which he might well have higher-priority > tasks requiring his attention. But without that performance information, > we are all just engaging in baseless speculation. The patch helps, but does not get us back to where we were before: Baseline: 3c8fb5044 with ac1bea85781e9004d reverted: root@bigbox:~/will-it-scale# ./open1_processes -t 160 -s 30 ... average:57710064 3c8fb5044 with Paul's early version with the magic 7: root@bigbox:~/will-it-scale# ./open1_processes -t 160 -s 30 ... average:48363361 It was down at 43M or 44M without the new patch. full spew: 3c8fb50445833b93f69b6b703a29aae3523cad0c with ac1bea85781e9004d reverted: root@bigbox:~/will-it-scale# ./open1_processes -t 160 -s 30 warmup min:366329 max:421686 total:63727790 min:358758 max:406036 total:62561168 min:298435 max:340355 total:51711000 min:343707 max:383812 total:59554601 min:310652 max:356571 total:54016014 min:337738 max:382557 total:59146223 measurement min:317628 max:363489 total:55230696 min:341875 max:392621 total:59910047 min:331979 max:376582 total:58074347 min:342835 max:388481 total:59644247 min:327282 max:374283 total:56897588 min:321668 max:373622 total:55799061 min:336575 max:387027 total:58948777 min:350269 max:397098 total:61510405 min:336949 max:382367 total:58640224 min:327913 max:371026 total:56833639 min:322377 max:375011 total:56923970 min:354508 max:399130 total:61628878 min:319998 max:367493 total:55624467 min:337322 max:379689 total:58425775 min:325701 max:369950 total:56382432 min:318423 max:364997 total:55662597 min:332930 max:374174 total:57881582 min:324787 max:371432 total:56881287 min:335136 max:381850 total:58661101 min:329253 max:377998 total:58146731 min:353550 max:399807 total:61031126 min:312443 max:358633 total:55092296 min:344435 max:396344 total:61129639 min:332426 max:394539 total:58307766 min:322235 max:367385 total:56477056 min:326722 max:362761 total:55421905 min:318183 max:366510 total:56260638 min:321812 max:372084 total:56639167 min:328016 max:379484 total:57794343 min:314929 max:364644 total:55440152 average:57710064 3c8fb50445833b93f69b6b703a29aae3523cad0c with paul's early version and the magic 7: root@bigbox:~/will-it-scale# ./open1_processes -t 160 -s 30 testcase:Separate file open/close warmup min:310891 max:364268 total:54015547 min:283886 max:333177 total:49992270 min:275451 max:314699 total:47775422 min:275164 max:316351 total:47720614 min:283434 max:326614 total:49156206 min:276475 max:320313 total:48469874 measurement min:274589 max:323239 total:48149462 min:280194 max:328827 total:49338289 min:277830 max:327060 total:48962337 min:281689 max:325917 total:49211850 min:271332 max:308350 total:46813631 min:275384 max:319016 total:47366390 min:276728 max:318277 total:47752679 min:275616 max:317111 total:47955871 min:278882 max:319082 total:47864449 min:267076 max:312427 total:47225886 min:279400 max:322798 total:48561113 min:279140 max:317367 total:47762975 min:278772 max:325575 total:49001990 min:271660 max:311780 total:47349871 min:283508 max:326299 total:49516078 min:284946 max:327525 total:49468752 min:271924 max:316507 total:47867902 min:279669 max:313937 total:47582153 min:272887 max:319545 total:47725521 min:281685 max:323791 total:48620478 min:280714 max:324849 total:48804594 min:283307 max:327424 total:49153787 min:280186 max:323924 total:48618088 min:270821 max:311985 total:47194656 min:282145 max:327910 total:48728398 min:276035 max:326523 total:48895232 min:275433 max:317441 total:48054952 min:276840 max:320486 total:48297727 min:280297 max:320323 total:48736783 min:286099 max:327522 total:50318962 average:48363361 -- 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/