From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751735Ab2LALGq (ORCPT ); Sat, 1 Dec 2012 06:06:46 -0500 Received: from mxout2.iskon.hr ([213.191.128.81]:57135 "EHLO mxout2.iskon.hr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751339Ab2LALGo (ORCPT ); Sat, 1 Dec 2012 06:06:44 -0500 X-Remote-IP: 213.191.128.133 Date: Sat, 01 Dec 2012 12:06:41 +0100 From: Zlatko Calusic Organization: Iskon Internet d.d. User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121031 Icedove/16.0.2 MIME-Version: 1.0 To: Tejun Heo CC: linux-kernel@vger.kernel.org References: <50A78AA9.5040904@iskon.hr> <20121130225200.GB6021@htj.dyndns.org> <20121130225545.GC6021@htj.dyndns.org> In-Reply-To: <20121130225545.GC6021@htj.dyndns.org> Message-ID: <50B9E4C1.2050002@iskon.hr> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: High context switch rate, ksoftirqd's chewing cpu X-Anti-Virus: Kaspersky Anti-Virus for Linux Mail Server 5.6.45/RELEASE, bases: 20121201 #8574610, check: 20121201 clean X-SpamTest-Envelope-From: zlatko.calusic@iskon.hr X-SpamTest-Group-ID: 00000000 X-SpamTest-Info: Profiles 39739 [Dec 01 2012] X-SpamTest-Method: none X-SpamTest-Rate: 0 X-SpamTest-SPF: none X-SpamTest-Status: Not detected X-SpamTest-Status-Extended: not_detected X-SpamTest-Version: SMTP-Filter Version 3.0.0 [0284], KAS30/Release Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30.11.2012 23:55, Tejun Heo wrote: > Hello, again. > > Can you please try this patch? Thanks! > > diff --git a/kernel/workqueue.c b/kernel/workqueue.c > index 042d221..26368ef 100644 > --- a/kernel/workqueue.c > +++ b/kernel/workqueue.c > @@ -1477,7 +1477,10 @@ bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq, > } while (unlikely(ret == -EAGAIN)); > > if (likely(ret >= 0)) { > - __queue_delayed_work(cpu, wq, dwork, delay); > + if (!delay) > + __queue_work(cpu, wq, &dwork->work); > + else > + __queue_delayed_work(cpu, wq, dwork, delay); > local_irq_restore(flags); > } > > I have good news. The patch fixes the regression! To doublecheck and provide you additional data, I updated to the latest Linus kernel (commit 7c17e48), recompiled (WITHOUT the patch), rebooted and this is what vmstat 1 looks like: procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 1 0 0 2957924 43676 655840 0 0 868 460 1446 38112 1 1 75 23 0 0 0 2957436 43684 655672 0 0 8 1290 941 30743 1 2 96 1 0 0 0 2957416 43708 656120 0 0 300 501 755 23642 1 2 89 9 1 0 0 2957648 43740 656592 0 0 632 162 946 19837 1 3 81 17 0 0 0 2950104 43740 664660 0 0 8192 0 550 326 1 1 91 8 0 0 0 2950600 43772 664092 0 0 148 289 691 39594 0 1 90 9 0 0 0 2939580 43924 674612 0 0 5568 115 2424 38662 5 4 77 15 0 1 0 2944888 43932 669580 0 0 56 869 1095 20062 6 1 89 4 0 0 0 2945812 43936 670524 0 0 824 92 824 49790 0 2 93 5 1 0 0 2945724 44084 670656 0 0 348 91 650 26455 1 1 89 10 0 2 0 2945356 44380 670848 0 0 536 161 718 18824 1 2 76 22 0 0 0 2944432 44400 671216 0 0 156 534 684 16232 2 1 81 17 0 0 0 2943660 44412 671544 0 0 292 120 562 49618 1 3 87 10 0 0 0 2943740 44412 671520 0 0 0 9 393 7247 0 0 100 0 0 0 0 2943608 44420 671812 0 0 276 42 507 36329 1 1 96 3 0 0 0 2943704 44420 671996 0 0 176 0 405 269 0 0 100 0 0 0 0 2943548 44428 671964 0 0 0 238 534 14823 0 1 99 0 0 0 0 2943136 44444 672156 0 0 212 692 698 29321 1 2 86 11 Then I applied the patch and this is how vmstat 1 looks now (WITH the patch): procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 1 0 0 2736628 35160 897708 0 0 8 293 1172 2493 17 3 79 1 0 0 0 2737336 35172 897944 0 0 156 43 883 971 3 0 95 3 0 0 0 2736500 35212 898252 0 0 292 5564 1267 2168 14 2 79 5 0 0 0 2736056 35356 898864 0 0 596 51 1029 1344 2 3 90 6 0 0 0 2735732 35504 899284 0 0 516 82 1225 1495 2 2 85 11 0 1 0 2734052 35508 900324 0 0 512 91 1149 1225 2 2 93 4 0 0 0 2733980 35508 899820 0 0 0 17 918 1164 2 1 96 1 0 2 0 2733988 35812 899940 0 0 656 1764 1097 1549 3 2 79 17 0 0 0 2733792 35820 900348 0 0 40 76 1303 1299 2 3 83 13 0 0 0 2733888 35820 900344 0 0 0 17 914 1085 2 1 97 0 0 0 0 2733316 35952 900364 0 0 144 235 1062 1316 1 2 95 3 0 0 0 2733012 36092 900412 0 0 176 11 1112 1469 3 1 92 4 0 0 0 2732732 36236 900444 0 0 160 709 932 1022 2 1 93 5 1 0 0 2732128 36384 900400 0 0 156 8987 1491 2519 12 3 82 3 0 0 0 2732128 36384 900416 0 0 0 34 927 1376 5 2 93 0 0 0 0 2732044 36540 900788 0 0 444 82 963 1278 3 1 87 8 1 0 0 2732020 36680 900796 0 0 168 2 883 1041 1 2 94 2 0 0 0 2731228 36700 901456 0 0 324 196 882 1125 2 0 94 4 Observe the difference in the cs column! I hope this gets in before 3.7.0. Good work Tejun! Best regards, -- Zlatko