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Groups > linux.kernel > #1443642

Re: Severe performance regression w/ 4.4+ on Android due to cgroup locking changes

From Oleg Nesterov <oleg@redhat.com>
Newsgroups linux.kernel
Subject Re: Severe performance regression w/ 4.4+ on Android due to cgroup locking changes
Date 2016-07-14 19:50 +0200
Message-ID <rUSVP-4ga-25@gated-at.bofh.it> (permalink)
References (5 earlier) <rURZM-3En-13@gated-at.bofh.it> <rURZM-3En-11@gated-at.bofh.it> <rUSj8-41y-9@gated-at.bofh.it> <rUSsO-45I-19@gated-at.bofh.it> <rUSM9-4cH-1@gated-at.bofh.it>
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On 07/14, John Stultz wrote:
>
> I'm not supposed to be applying this on-top of
> Paul's change, right?

Right, unless I am totally confused,

> > Just in case, could you try the patch below? Of course, without other
> > optimizations from Peter, this change makes cgroup_threadgroup_rwsem
> > much worse than a plain rw_semaphore.
> >
> > Oleg.
> >
> > --- x/kernel/cgroup.c
> > +++ x/kernel/cgroup.c
> > @@ -5605,6 +5605,8 @@ int __init cgroup_init(void)
> >         BUG_ON(cgroup_init_cftypes(NULL, cgroup_dfl_base_files));
> >         BUG_ON(cgroup_init_cftypes(NULL, cgroup_legacy_base_files));
> >
> > +       rcu_sync_enter(&cgroup_threadgroup_rwsem.rss);
> > +
> 
> 
> So adding this does make a huge difference ontop of Peter's patch.

Ah, sorry for confusion. I meant, you could try this one-liner without
any other changes.

But we will need the "slow mode optimization" part from Peter's patch
anyway, otherwise percpu_rw_semaphore simply makes no sense for
cgroup_threadgroup_rwsem.

Oleg.

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Thread

Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes John Stultz <john.stultz@linaro.org> - 2016-07-13 02:10 +0200
  Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Peter Zijlstra <peterz@infradead.org> - 2016-07-13 10:30 +0200
    Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-07-13 16:50 +0200
      Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-07-13 20:40 +0200
  Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Tejun Heo <tj@kernel.org> - 2016-07-13 20:30 +0200
    Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Tejun Heo <tj@kernel.org> - 2016-07-13 20:40 +0200
      Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Tejun Heo <tj@kernel.org> - 2016-07-13 22:20 +0200
        Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Peter Zijlstra <peterz@infradead.org> - 2016-07-13 22:30 +0200
          Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Tejun Heo <tj@kernel.org> - 2016-07-13 22:50 +0200
            Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Peter Zijlstra <peterz@infradead.org> - 2016-07-13 23:00 +0200
              Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Tejun Heo <tj@kernel.org> - 2016-07-13 23:10 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-07-13 23:20 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-07-13 23:50 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes John Stultz <john.stultz@linaro.org> - 2016-07-13 23:50 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-07-14 00:20 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes John Stultz <john.stultz@linaro.org> - 2016-07-14 00:40 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-07-14 01:10 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-07-14 01:10 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Tejun Heo <tj@kernel.org> - 2016-07-14 13:40 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Peter Zijlstra <peterz@infradead.org> - 2016-07-14 14:10 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Tejun Heo <tj@kernel.org> - 2016-07-14 14:10 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Peter Zijlstra <peterz@infradead.org> - 2016-07-14 14:30 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Tejun Heo <tj@kernel.org> - 2016-07-14 17:10 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Tejun Heo <tj@kernel.org> - 2016-07-14 17:30 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Peter Zijlstra <peterz@infradead.org> - 2016-07-14 18:40 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Oleg Nesterov <oleg@redhat.com> - 2016-07-14 19:40 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes John Stultz <john.stultz@linaro.org> - 2016-07-14 19:00 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes John Stultz <john.stultz@linaro.org> - 2016-07-14 00:30 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Tejun Heo <tj@kernel.org> - 2016-07-14 00:10 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-07-14 00:40 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Peter Zijlstra <peterz@infradead.org> - 2016-07-14 09:00 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Tejun Heo <tj@kernel.org> - 2016-07-14 13:30 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Peter Zijlstra <peterz@infradead.org> - 2016-07-14 14:20 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Tejun Heo <tj@kernel.org> - 2016-07-14 17:20 +0200
              Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Tejun Heo <tj@kernel.org> - 2016-07-13 23:10 +0200
              Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-07-13 23:10 +0200
              Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Peter Zijlstra <peterz@infradead.org> - 2016-07-14 15:20 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Peter Zijlstra <peterz@infradead.org> - 2016-07-14 16:20 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Oleg Nesterov <oleg@redhat.com> - 2016-07-14 17:00 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Peter Zijlstra <peterz@infradead.org> - 2016-07-14 18:20 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Peter Zijlstra <peterz@infradead.org> - 2016-07-14 18:40 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Oleg Nesterov <oleg@redhat.com> - 2016-07-14 19:10 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-07-14 18:30 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Peter Zijlstra <peterz@infradead.org> - 2016-07-14 18:50 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-07-14 19:20 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes John Stultz <john.stultz@linaro.org> - 2016-07-14 18:50 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Peter Zijlstra <peterz@infradead.org> - 2016-07-14 18:50 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes John Stultz <john.stultz@linaro.org> - 2016-07-14 19:10 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Oleg Nesterov <oleg@redhat.com> - 2016-07-14 19:20 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes John Stultz <john.stultz@linaro.org> - 2016-07-14 19:40 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Oleg Nesterov <oleg@redhat.com> - 2016-07-14 19:50 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes John Stultz <john.stultz@linaro.org> - 2016-07-14 20:00 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Oleg Nesterov <oleg@redhat.com> - 2016-07-14 20:10 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Peter Zijlstra <peterz@infradead.org> - 2016-07-14 20:40 +0200
                Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Peter Zijlstra <peterz@infradead.org> - 2016-07-14 21:40 +0200
            Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes John Stultz <john.stultz@linaro.org> - 2016-07-13 23:00 +0200
          Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Peter Zijlstra <peterz@infradead.org> - 2016-07-13 23:00 +0200
            Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-07-13 23:10 +0200
          Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-07-13 23:00 +0200
            Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Dmitry Shmidt <dimitrysh@google.com> - 2016-07-13 23:10 +0200
              Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-07-13 23:10 +0200
              Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes John Stultz <john.stultz@linaro.org> - 2016-07-13 23:10 +0200
      Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes John Stultz <john.stultz@linaro.org> - 2016-07-13 22:20 +0200
      Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Dmitry Shmidt <dimitrysh@google.com> - 2016-07-13 22:40 +0200
    Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Colin Cross <ccross@google.com> - 2016-07-13 22:50 +0200
      Re: Severe performance regression w/ 4.4+ on Android due to cgroup  locking changes Tejun Heo <tj@kernel.org> - 2016-07-13 23:00 +0200

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