From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756575AbXE3Scg (ORCPT ); Wed, 30 May 2007 14:32:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753909AbXE3Sc1 (ORCPT ); Wed, 30 May 2007 14:32:27 -0400 Received: from smtp.osdl.org ([207.189.120.12]:59286 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753852AbXE3Sc0 (ORCPT ); Wed, 30 May 2007 14:32:26 -0400 Date: Wed, 30 May 2007 11:20:56 -0700 From: Stephen Hemminger To: Andrew Morton Cc: Venki Pallipadi , linux-kernel , netdev@vger.kernel.org Subject: Re: [PATCH 3/4] Make net watchdog timers 1 sec jiffy aligned Message-ID: <20070530112056.0aeb9498@freepuppy> In-Reply-To: <20070530105936.6c988da5.akpm@linux-foundation.org> References: <20070529180112.GC5411@linux-os.sc.intel.com> <20070530105936.6c988da5.akpm@linux-foundation.org> Organization: Linux Foundation X-Mailer: Sylpheed-Claws 2.6.0 (GTK+ 2.10.11; x86_64-pc-linux-gnu) 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 On Wed, 30 May 2007 10:59:36 -0700 Andrew Morton wrote: > On Tue, 29 May 2007 11:01:13 -0700 > Venki Pallipadi wrote: > > > round_jiffies for net dev watchdog timer. > > > > Signed-off-by: Venkatesh Pallipadi > > > > Index: linux-2.6.22-rc-mm/net/sched/sch_generic.c > > =================================================================== > > --- linux-2.6.22-rc-mm.orig/net/sched/sch_generic.c 2007-05-24 11:16:03.000000000 -0700 > > +++ linux-2.6.22-rc-mm/net/sched/sch_generic.c 2007-05-25 15:10:02.000000000 -0700 > > @@ -224,7 +224,8 @@ > > if (dev->tx_timeout) { > > if (dev->watchdog_timeo <= 0) > > dev->watchdog_timeo = 5*HZ; > > - if (!mod_timer(&dev->watchdog_timer, jiffies + dev->watchdog_timeo)) > > + if (!mod_timer(&dev->watchdog_timer, > > + round_jiffies(jiffies + dev->watchdog_timeo))) > > dev_hold(dev); > > } > > } > > Please cc netdev on net patches. > > Again, I worry that if people set the watchdog timeout to, say, 0.1 seconds > then they will get one second, which is grossly different. > > And if they were to set it to 1.5 seconds, they'd get 2.0 which is pretty > significant, too. Alternatively, we could change to a timer that is pushed forward after each TX, maybe using hrtimer and hrtimer_forward(). That way the timer would never run in normal case. -- Stephen Hemminger