Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754961AbYKJKWV (ORCPT ); Mon, 10 Nov 2008 05:22:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753936AbYKJKWM (ORCPT ); Mon, 10 Nov 2008 05:22:12 -0500 Received: from viefep18-int.chello.at ([213.46.255.22]:55194 "EHLO viefep18-int.chello.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753834AbYKJKWL (ORCPT ); Mon, 10 Nov 2008 05:22:11 -0500 X-SourceIP: 213.46.9.244 Subject: Re: [PATCH] Add hierarchical accounting to cpu accounting controller From: Peter Zijlstra To: bharata@linux.vnet.ibm.com Cc: KAMEZAWA Hiroyuki , Dhaval Giani , Li Zefan , Balbir Singh , Paul Menage , linux-kernel@vger.kernel.org, Srivatsa Vaddagiri , Ingo Molnar In-Reply-To: <20081104124937.GB4898@in.ibm.com> References: <20081024050830.GA4387@in.ibm.com> <6599ad830810241037h575ec17bgb43f750d99bd1518@mail.gmail.com> <20081025060157.GA4614@in.ibm.com> <6599ad830810250838q3f96644bm6dfee8ba9f35dfa3@mail.gmail.com> <20081027101703.e954071d.kamezawa.hiroyu@jp.fujitsu.com> <20081027044319.GA4386@in.ibm.com> <661de9470810262357y6c560facl87dcaea3ce35e3ac@mail.gmail.com> <49057ADD.1050705@cn.fujitsu.com> <20081030171622.GA19872@linux.vnet.ibm.com> <20081031094041.194a32d9.kamezawa.hiroyu@jp.fujitsu.com> <20081104124937.GB4898@in.ibm.com> Content-Type: text/plain Date: Mon, 10 Nov 2008 11:22:41 +0100 Message-Id: <1226312561.2697.4093.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3568 Lines: 108 On Tue, 2008-11-04 at 18:19 +0530, Bharata B Rao wrote: > Add hierarchical accounting to cpu accounting controller and cpuacct > documentation. > > Currently, while charging the task's cputime to its accounting group, > the accounting group hierarchy isn't updated. This patch charges the cputime > of a task to its accounting group and all its parent accounting groups. > > Reported-by: Srivatsa Vaddagiri > Signed-off-by: Bharata B Rao > CC: Peter Zijlstra > CC: Ingo Molnar > CC: Srivatsa Vaddagiri > Reviewed-by: Paul Menage Seems sane and simple enough. Acked-by: Peter Zijlstra Ingo? > --- > Documentation/controllers/cpuacct.txt | 32 ++++++++++++++++++++++++++++++++ > kernel/sched.c | 10 ++++++++-- > 2 files changed, 40 insertions(+), 2 deletions(-) > > --- /dev/null > +++ b/Documentation/controllers/cpuacct.txt > @@ -0,0 +1,32 @@ > +CPU Accounting Controller > +------------------------- > + > +The CPU accounting controller is used to group tasks using cgroups and > +account the CPU usage of these group of tasks. > + > +The CPU accounting controller supports multi-hierarchy groups. An accounting > +group accumulates the CPU usage of all of it's child groups and > +the tasks directly present in it's group. > + > +Accounting groups can be created by first mounting the cgroup filesystem. > + > +# mkdir /cgroups > +# mount -t cgroup -ocpuacct none /cgroups > + > +With the above step, the initial or the parent accounting group > +becomes visible at /cgroups. At bootup, this group comprises of all the > +tasks in the system. /cgroups/tasks lists the tasks in this cgroup. > +/cgroups/cpuacct.usage gives the CPU time (in nanoseconds) obtained by > +this group which is essentially the CPU time obtained by all the tasks > +in the system. > + > +New accounting groups can be created under the parent group /cgroups. > + > +# cd /cgroups > +# mkdir g1 > +# echo $$ > g1 > + > +The above steps create a new group g1 and move the current shell > +process (bash) into it. CPU time consumed by this bash and it's children > +can be obtained from g1/cpuacct.usage and the same gets accumulated in > +/cgroups/cpuacct.usage also. > --- a/kernel/sched.c > +++ b/kernel/sched.c > @@ -9236,6 +9236,7 @@ struct cpuacct { > struct cgroup_subsys_state css; > /* cpuusage holds pointer to a u64-type object on every cpu */ > u64 *cpuusage; > + struct cpuacct *parent; > }; > > struct cgroup_subsys cpuacct_subsys; > @@ -9269,6 +9270,9 @@ static struct cgroup_subsys_state *cpuac > return ERR_PTR(-ENOMEM); > } > > + if (cgrp->parent) > + ca->parent = cgroup_ca(cgrp->parent); > + > return &ca->css; > } > > @@ -9348,14 +9352,16 @@ static int cpuacct_populate(struct cgrou > static void cpuacct_charge(struct task_struct *tsk, u64 cputime) > { > struct cpuacct *ca; > + int cpu; > > if (!cpuacct_subsys.active) > return; > > + cpu = task_cpu(tsk); > ca = task_ca(tsk); > - if (ca) { > - u64 *cpuusage = percpu_ptr(ca->cpuusage, task_cpu(tsk)); > > + for (; ca; ca = ca->parent) { > + u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu); > *cpuusage += cputime; > } > } -- 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/