From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756474AbXKRAD3 (ORCPT ); Sat, 17 Nov 2007 19:03:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753366AbXKRADU (ORCPT ); Sat, 17 Nov 2007 19:03:20 -0500 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:42309 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753945AbXKRADT (ORCPT ); Sat, 17 Nov 2007 19:03:19 -0500 Date: Sat, 17 Nov 2007 16:03:16 -0800 (PST) Message-Id: <20071117.160316.162501140.davem@davemloft.net> To: andi@firstfloor.org Cc: arjan@infradead.org, dada1@cosmosbay.com, linux-kernel@vger.kernel.org, netdev@vget.kernel.org Subject: Re: [NET]: rt_check_expire() can take a long time, add a cond_resched() From: David Miller In-Reply-To: References: <473D18A5.2090309@cosmosbay.com> <20071115215938.44233733@laptopd505.fenrus.org> X-Mailer: Mew version 5.2 on Emacs 22.1 / 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 From: Andi Kleen Date: Sat, 17 Nov 2007 13:56:08 +0100 > Arjan van de Ven writes: > >> > > >> > Its not that cheap. The ChangeLog included my own numbers, on a > >> > Pentium M machine. (i686, 1.6 GHz, 1.5 GB ram) > >> > > >> > Without "if (need_resched())" (so calling need_resched() X.XXX.XXX > >> > times), each run takes 88ms > >> > > >> > With the extra check (and *much* less function calls), each run > >> > takes 25ms > > ms?!? The numbers sound wrong. Wrong unit? Read what Eric is saying. He is saying "any entire run" purging the routing cache takes that long, not just one call.