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Groups > linux.kernel > #1442851

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

From John Stultz <john.stultz@linaro.org>
Newsgroups linux.kernel
Subject Re: Severe performance regression w/ 4.4+ on Android due to cgroup locking changes
Date 2016-07-13 23:00 +0200
Message-ID <rUzqa-8bo-29@gated-at.bofh.it> (permalink)
References (2 earlier) <rUxeG-6P0-17@gated-at.bofh.it> <rUyNs-7VU-13@gated-at.bofh.it> <rUyNs-7VU-11@gated-at.bofh.it> <rUyX7-7ZC-1@gated-at.bofh.it> <rUzgu-87F-9@gated-at.bofh.it>
Organization linux.* mail to news gateway

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On Wed, Jul 13, 2016 at 1:39 PM, Tejun Heo <tj@kernel.org> wrote:
> Hello,
>
> On Wed, Jul 13, 2016 at 10:26:57PM +0200, Peter Zijlstra wrote:
>> > So, it's a percpu rwsem issue then.  I haven't really followed the
>> > perpcpu rwsem changes closely.  Oleg, are multi-milisec delay expected
>> > on down write expected with the current implementation of
>> > percpu_rwsem?
>>
>> There is a synchronize_sched() in there, so sorta. That thing is heavily
>> geared towards readers, as is the only 'sane' choice for global locks.
>
> It used to use the expedited variant until 001dac627ff3
> ("locking/percpu-rwsem: Make use of the rcu_sync infrastructure"), so
> it might have been okay before then.

Just as a datapoint, just reverting 001dac627ff3
("locking/percpu-rwsem: Make use of the rcu_sync infrastructure"),
doesn't seem to help as much as your prior patch going to a normal
rwsem.

I'm consistently seeing values in the 100-550us range (with occasional
spikes around 6ms), with a max value at 36ms.

thanks
-john

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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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