Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161184AbWHJLl0 (ORCPT ); Thu, 10 Aug 2006 07:41:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161185AbWHJLl0 (ORCPT ); Thu, 10 Aug 2006 07:41:26 -0400 Received: from dsl027-180-168.sfo1.dsl.speakeasy.net ([216.27.180.168]:17302 "EHLO sunset.davemloft.net") by vger.kernel.org with ESMTP id S1161184AbWHJLlZ (ORCPT ); Thu, 10 Aug 2006 07:41:25 -0400 Date: Thu, 10 Aug 2006 04:41:33 -0700 (PDT) Message-Id: <20060810.044133.50597818.davem@davemloft.net> To: axboe@suse.de Cc: linux-kernel@vger.kernel.org Subject: Re: softirq considered harmful From: David Miller In-Reply-To: <20060810110627.GM11829@suse.de> References: <20060810110627.GM11829@suse.de> X-Mailer: Mew version 4.2 on Emacs 21.4 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 901 Lines: 24 From: Jens Axboe Date: Thu, 10 Aug 2006 13:06:27 +0200 > run_timer_softirq+0x0/0x18e: took 3750 > run_timer_softirq+0x0/0x18e: took 2595 > run_timer_softirq+0x0/0x18e: took 6265 > run_timer_softirq+0x0/0x18e: took 2608 > > So from 2.6 to 6.2msecs just that handler, auch. During normal running, > the 2.6 msec variant triggers quite often. It would be interesting to know what timers ran when the overhead got this high. You can probably track this with a per-cpu array of pointers, have run_timer_softirq record the t->func pointers into the array as it runs the current slew of timers, then if the "took" is very large dump the array. - 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/