Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753930AbZJAWtW (ORCPT ); Thu, 1 Oct 2009 18:49:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753897AbZJAWtV (ORCPT ); Thu, 1 Oct 2009 18:49:21 -0400 Received: from kroah.org ([198.145.64.141]:59995 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753893AbZJAWtU (ORCPT ); Thu, 1 Oct 2009 18:49:20 -0400 Date: Thu, 1 Oct 2009 15:31:05 -0700 From: Greg KH To: Michael Abbott Cc: Andrew Morton , Johan van Baarlen , Linux Kernel Mailing List , Jan Engelhardt , Martin Schwidefsky , Linus Torvalds , stable@kernel.org Subject: Re: [stable] [GIT PULL] cputime tree Message-ID: <20091001223105.GF28208@kroah.com> References: <20090924133136.7b7c834e@mschwide.boeblingen.de.ibm.com> <20090924095106.62294617.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2937 Lines: 74 On Thu, Sep 24, 2009 at 08:49:10PM +0100, Michael Abbott wrote: > On Thu, 24 Sep 2009, Andrew Morton wrote: > > On Thu, 24 Sep 2009 13:31:36 +0200 Martin Schwidefsky wrote: > > > > > Hi Linus, > > > > > > with git commit 79741dd "idle cputime accounting" the semantic > > > of the stime field of the idle processes has changed. It used to > > > contain the amount of time the idle process has been scheduled. > > > Since git commit 79741dd is contains the cpu time spent in the > > > system by the idle process. > > > > > > This change broke the output of second field of /proc/uptime. On > > > systems without VIRT_CPU_ACCOUNTING the field is always zero. > > > The legacy output of the field is the amount of time the idle > > > process has been scheduled on cpu #0. It is good enough to > > > calculate the load on an uni-processor system, it is useless > > > on a multi-processor. To restore the legacy behaviour and give > > > meaning to the multi-processor case the best we could come up > > > with is to add the idle time over all cpus. That fixes uni- > > > processors systems and gives a defined semantic on smp. > > > > > > So please pull from 'cputime' branch of > > > > > > git://git390.marist.edu/pub/scm/linux-2.6.git cputime > > > > > > to receive the following updates: > > > > > > Michael Abbott (1): > > > Fix idle time field in /proc/uptime > > > > > > fs/proc/uptime.c | 7 ++++++- > > > 1 files changed, 6 insertions(+), 1 deletions(-) > > > > > > diff --git a/fs/proc/uptime.c b/fs/proc/uptime.c > > > index 0c10a0b..766b1d4 100644 > > > --- a/fs/proc/uptime.c > > > +++ b/fs/proc/uptime.c > > > @@ -4,13 +4,18 @@ > > > #include > > > #include > > > #include > > > +#include > > > #include > > > > > > static int uptime_proc_show(struct seq_file *m, void *v) > > > { > > > struct timespec uptime; > > > struct timespec idle; > > > - cputime_t idletime = cputime_add(init_task.utime, init_task.stime); > > > + int i; > > > + cputime_t idletime = cputime_zero; > > > + > > > + for_each_possible_cpu(i) > > > + idletime = cputime64_add(idletime, kstat_cpu(i).cpustat.idle); > > > > > > do_posix_clock_monotonic_gettime(&uptime); > > > monotonic_to_bootbased(&uptime); > > > > This is a regression fix, iirc? One which is applicable for several > > 2.6.x kernel versions? > > Yes indeed, all since the regression was introduced I think around about > .28 (though I seem to remember having to tweak the code a little when > rebasing it forward). Thanks, I've queued this up for .30 and .31 stable kernels. greg k-h -- 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/