From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751267AbaDSI0x (ORCPT ); Sat, 19 Apr 2014 04:26:53 -0400 Received: from mga01.intel.com ([192.55.52.88]:32924 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750905AbaDSI0t (ORCPT ); Sat, 19 Apr 2014 04:26:49 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,887,1389772800"; d="scan'208";a="515794966" Date: Sat, 19 Apr 2014 16:26:22 +0800 From: Fengguang Wu To: "Paul E. McKenney" Cc: LKML , lkp@01.org Subject: [rcu] 10a94227ba2: -2.0% will-it-scale.per_process_ops Message-ID: <20140419082622.GA29303@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Heirloom mailx 12.5 6/20/10 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Paul, FYI, we noticed the below changes on git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git next.2014.04.16b commit 10a94227ba229f1b05672754dc318a8fe7982c95 ("rcu: Update cpu_needs_another_gp() for futures from non-NOCB CPUs") test case: nhm4/micro/will-it-scale/lseek1 11ba5ab363b9359 10a94227ba229f1b05672754d --------------- ------------------------- 11210675 ~ 0% -2.0% 10985451 ~ 0% TOTAL will-it-scale.per_process_ops 1.24 ~ 5% -33.4% 0.83 ~ 5% TOTAL perf-profile.cpu-cycles.trace_hardirqs_off_caller.lseek64 3.88 ~ 2% +49.0% 5.79 ~ 0% TOTAL perf-profile.cpu-cycles.trace_hardirqs_on_thunk.lseek64 295 ~16% +27.0% 375 ~ 8% TOTAL cpuidle.C1E-NHM.usage 45061 ~ 2% +16.7% 52590 ~ 2% TOTAL cpuidle.C6-NHM.usage 1.21 ~ 4% +5.8% 1.28 ~ 4% TOTAL perf-profile.cpu-cycles.shmem_file_llseek.sys_lseek.system_call_fastpath.lseek64 4206 ~ 1% -78.6% 900 ~ 8% TOTAL interrupts.IWI 14303 ~ 1% +26.7% 18120 ~ 1% TOTAL interrupts.0:IO-APIC-edge.timer 3228 ~ 4% -17.2% 2672 ~ 6% TOTAL interrupts.RES 182 ~ 2% -8.1% 167 ~ 3% TOTAL time.user_time 235 ~ 2% +6.2% 250 ~ 2% TOTAL time.system_time 379471 ~ 0% +1.2% 384127 ~ 0% TOTAL interrupts.LOC Legend: ~XX% - stddev percent [+-]XX% - change percent It does effectively eliminate interrupts.IWI: interrupts.IWI 4500 ++-*-----*-------*--------------------------------------------------+ |.. *. + .*. .*..*. .*..*..*.. .*..*..*..*.*..*..* 4000 *+ *. *. *. *.. .*..*. | 3500 ++ * | | | 3000 ++ | 2500 ++ | | | 2000 ++ | 1500 ++ | | | 1000 ++ O O O O O O O 500 ++ O | | | 0 O+-O--O--O-O--O--O--O--O--O-O--O--O--O--O--O-O----------------------+ [*] bisect-good sample [O] bisect-bad sample Thanks, Fengguang