[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Wed, 02 Feb 2011 12:29:20 +0100
From: Peter Zijlstra <peterz@...radead.org>
To: eranian@...gle.com
Cc: linux-kernel@...r.kernel.org, mingo@...e.hu, paulus@...ba.org,
davem@...emloft.net, fweisbec@...il.com,
perfmon2-devel@...ts.sf.net, eranian@...il.com,
robert.richter@....com, acme@...hat.com, lizf@...fujitsu.com,
Paul Menage <menage@...gle.com>,
Balbir Singh <balbir@...ux.vnet.ibm.com>
Subject: Re: [PATCH 1/2] perf_events: add cgroup support (v8)
On Thu, 2011-01-20 at 15:39 +0100, Peter Zijlstra wrote:
> On Thu, 2011-01-20 at 15:30 +0200, Stephane Eranian wrote:
> > @@ -4259,8 +4261,20 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks)
> >
> > /* Reassign the task to the init_css_set. */
> > task_lock(tsk);
> > + /*
> > + * we mask interrupts to prevent:
> > + * - timer tick to cause event rotation which
> > + * could schedule back in cgroup events after
> > + * they were switched out by perf_cgroup_sched_out()
> > + *
> > + * - preemption which could schedule back in cgroup events
> > + */
> > + local_irq_save(flags);
> > + perf_cgroup_sched_out(tsk);
> > cg = tsk->cgroups;
> > tsk->cgroups = &init_css_set;
> > + perf_cgroup_sched_in(tsk);
> > + local_irq_restore(flags);
> > task_unlock(tsk);
> > if (cg)
> > put_css_set_taskexit(cg);
>
> So you too need a callback on cgroup change there.. Li, Paul, any chance
> we can fix this cgroup_subsys::exit callback? The scheduler code needs
> to do funny thing because its in the wrong place as well.
cgroup guys? Shall I just fix this exit thing since the only user seems
to be the scheduler and now perf for both of which its unfortunate at
best?
Balbir, memcontrol.c uses pre_destroy(), I pose that using this method
is broken per definition since it makes the cgroup empty notification
void.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists