Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752981Ab1BBHHv (ORCPT ); Wed, 2 Feb 2011 02:07:51 -0500 Received: from e6.ny.us.ibm.com ([32.97.182.146]:48258 "EHLO e6.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752903Ab1BBHHs (ORCPT ); Wed, 2 Feb 2011 02:07:48 -0500 Date: Tue, 1 Feb 2011 23:07:43 -0800 From: Matt Helsley To: jacob.jun.pan@linux.intel.com Cc: LKML , Li Zefan , Arjan van de Ven , Paul Menage , "Kirill A. Shutemov" , container cgroup Subject: Re: [PATCH] cgroups: respect cgroup timer slack value in prctl Message-ID: <20110202070743.GO16432@count0.beaverton.ibm.com> References: <1296600103-15726-1-git-send-email-jacob.jun.pan@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1296600103-15726-1-git-send-email-jacob.jun.pan@linux.intel.com> User-Agent: Mutt/1.5.20 (2009-06-14) X-Content-Scanned: Fidelis XPS MAILER Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4311 Lines: 133 On Tue, Feb 01, 2011 at 02:41:43PM -0800, jacob.jun.pan@linux.intel.com wrote: > From: Jacob Pan > > Per cgroup timer slack value is used to manage task groups > for more friendly power management behavior. Once a task is > attached to a cgroup, we should not allow user to change > (escape) the per cgroup restriction unless a more relaxed > timer slack value is given by user via prctl. > > Signed-off-by: Jacob Pan > --- > include/linux/cgroup.h | 13 +++++++++++++ Looks like the original two patches (one or more implementing: > kernel/cgroup_timer_slack.c | 4 ---- ) were not sent to containers@lists.linux-foundation.org ? > kernel/sys.c | 21 ++++++++++++++++++++- > 3 files changed, 33 insertions(+), 5 deletions(-) > > diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h > index ed4ba11..4405666 100644 > --- a/include/linux/cgroup.h > +++ b/include/linux/cgroup.h > @@ -627,6 +627,19 @@ bool css_is_ancestor(struct cgroup_subsys_state *cg, > unsigned short css_id(struct cgroup_subsys_state *css); > unsigned short css_depth(struct cgroup_subsys_state *css); > > +#ifdef CONFIG_CGROUP_TIMER_SLACK > +struct timer_slack_cgroup { > + struct cgroup_subsys_state css; > + unsigned long timer_slack_ns; > +}; > + > +static inline struct timer_slack_cgroup *task_timer_slack(struct task_struct *task) > +{ > + return container_of(task_subsys_state(task, timer_slack_subsys_id), > + struct timer_slack_cgroup, css); > +} > +#endif > + > #else /* !CONFIG_CGROUPS */ > > static inline int cgroup_init_early(void) { return 0; } > diff --git a/kernel/cgroup_timer_slack.c b/kernel/cgroup_timer_slack.c > index daa452d..1de122a 100644 > --- a/kernel/cgroup_timer_slack.c > +++ b/kernel/cgroup_timer_slack.c > @@ -4,10 +4,6 @@ > #include > > struct cgroup_subsys timer_slack_subsys; > -struct timer_slack_cgroup { > - struct cgroup_subsys_state css; > - unsigned long timer_slack_ns; > -}; > > static struct timer_slack_cgroup *cgroup_to_tslack_cgroup(struct cgroup *cgroup) > { > diff --git a/kernel/sys.c b/kernel/sys.c > index 7f5a0cd..433fcdb 100644 > --- a/kernel/sys.c > +++ b/kernel/sys.c > @@ -37,6 +37,8 @@ > #include > #include > #include > +#include > +#include > > #include > #include > @@ -1688,8 +1690,25 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, > if (arg2 <= 0) > current->timer_slack_ns = > current->default_timer_slack_ns; > - else > + else { > +#ifdef CONFIG_CGROUP_TIMER_SLACK > + /* only allow more relaxed slack value than > + * the attached timer slack cgroup allows. > + */ > + unsigned long cg_timer_slack; > + > + rcu_read_lock(); > + cg_timer_slack = task_timer_slack(current)->timer_slack_ns; > + rcu_read_unlock(); > + if (cg_timer_slack < arg2 || cg_timer_slack > + == TIMER_SLACK_NS_DEFAULT) > + current->timer_slack_ns = arg2; > + else > + return -EINVAL; > +#else Looks like this could be an inline function which returns the minimum timer slack allowed for the task. Then the code here would be: if (arg2 <= 0) current->timer_slack_ns = current->default_timer_slack_ns; else { if (arg2 < min_timer_slack_ns(tsk)) return -EINVAL; /* Can't set less than the minimum */ current->timer_slack_ns = arg2; } and the #ifdef CONFIG_CGROUP_TIMER_SLACK bits could be in a header as usual. Incidentally, shouldn't that really be -EPERM since it's not an invalid value -- just one that's not permitted due to restrictions imposed by the cgroup subsystem? > current->timer_slack_ns = arg2; > +#endif > + } > error = 0; > break; > case PR_MCE_KILL: > -- > 1.7.0.4 > > _______________________________________________ > Containers mailing list > Containers@lists.linux-foundation.org > https://lists.linux-foundation.org/mailman/listinfo/containers -- 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/