Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751536AbWA0Sz3 (ORCPT ); Fri, 27 Jan 2006 13:55:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751538AbWA0Sz3 (ORCPT ); Fri, 27 Jan 2006 13:55:29 -0500 Received: from mustang.oldcity.dca.net ([216.158.38.3]:56243 "HELO mustang.oldcity.dca.net") by vger.kernel.org with SMTP id S1751534AbWA0Sz3 (ORCPT ); Fri, 27 Jan 2006 13:55:29 -0500 Subject: Re: RCU latency regression in 2.6.16-rc1 From: Lee Revell To: paulmck@us.ibm.com Cc: dipankar@in.ibm.com, Ingo Molnar , linux-kernel , Linus Torvalds In-Reply-To: <20060126191809.GC6182@us.ibm.com> References: <20060124080157.GA25855@elte.hu> <1138090078.2771.88.camel@mindpipe> <20060124081301.GC25855@elte.hu> <1138090527.2771.91.camel@mindpipe> <20060124091730.GA31204@us.ibm.com> <20060124092330.GA7060@elte.hu> <1138095856.2771.103.camel@mindpipe> <20060124162846.GA7139@in.ibm.com> <20060124213802.GC7139@in.ibm.com> <1138224506.3087.22.camel@mindpipe> <20060126191809.GC6182@us.ibm.com> Content-Type: text/plain Date: Fri, 27 Jan 2006 13:55:22 -0500 Message-Id: <1138388123.3131.26.camel@mindpipe> Mime-Version: 1.0 X-Mailer: Evolution 2.5.4 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1427 Lines: 35 On Thu, 2006-01-26 at 11:18 -0800, Paul E. McKenney wrote: > > Xorg-2154 0d.s. 213us : call_rcu_bh (rt_run_flush) > > Xorg-2154 0d.s. 215us : local_bh_enable (rt_run_flush) > > Xorg-2154 0d.s. 216us : local_bh_enable (rt_run_flush) > > Xorg-2154 0d.s. 217us : local_bh_enable (rt_run_flush) > > Xorg-2154 0d.s. 218us : local_bh_enable (rt_run_flush) > > Xorg-2154 0d.s. 219us : local_bh_enable (rt_run_flush) > > Xorg-2154 0d.s. 220us : local_bh_enable (rt_run_flush) > > Xorg-2154 0d.s. 222us : local_bh_enable (rt_run_flush) > > Xorg-2154 0d.s. 223us : call_rcu_bh (rt_run_flush) > > > > [ zillions of these deleted ] > > > > Xorg-2154 0d.s. 7335us : local_bh_enable (rt_run_flush) > > Dipankar's latest patch should hopefully address this problem. > > Could you please give it a spin when you get a chance? Nope, no improvement at all, furthermore, the machine locked up once under heavy disk activity. I just got an 8ms+ latency from rt_run_flush that looks basically identical to the above. It's still flushing routes in huge batches: $ grep 'call_rcu_bh (rt_run_flush)' /proc/latency_trace | wc -l 2738 Lee - 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/