Re: [PATCH 03/16] sched/fair: Disregard idle task wakee_flips in wake_wide

2016-06-07 Thread Morten Rasmussen
On Thu, Jun 02, 2016 at 10:05:09AM +0200, Peter Zijlstra wrote: > On Wed, Jun 01, 2016 at 09:57:23PM +0200, Peter Zijlstra wrote: > > On Mon, May 23, 2016 at 01:00:10PM +0100, Morten Rasmussen wrote: > > > On Mon, May 23, 2016 at 01:12:07PM +0200, Mike Galbraith wrote: > > > > On Mon, 2016-05-23 at

Re: [PATCH 03/16] sched/fair: Disregard idle task wakee_flips in wake_wide

2016-06-02 Thread Peter Zijlstra
On Wed, Jun 01, 2016 at 09:57:23PM +0200, Peter Zijlstra wrote: > On Mon, May 23, 2016 at 01:00:10PM +0100, Morten Rasmussen wrote: > > On Mon, May 23, 2016 at 01:12:07PM +0200, Mike Galbraith wrote: > > > On Mon, 2016-05-23 at 11:58 +0100, Morten Rasmussen wrote: > > > > wake_wide() is based on ta

Re: [PATCH 03/16] sched/fair: Disregard idle task wakee_flips in wake_wide

2016-06-01 Thread Peter Zijlstra
On Mon, May 23, 2016 at 01:00:10PM +0100, Morten Rasmussen wrote: > On Mon, May 23, 2016 at 01:12:07PM +0200, Mike Galbraith wrote: > > On Mon, 2016-05-23 at 11:58 +0100, Morten Rasmussen wrote: > > > wake_wide() is based on task wakee_flips of the waker and the wakee to > > > decide whether an aff

Re: [PATCH 03/16] sched/fair: Disregard idle task wakee_flips in wake_wide

2016-05-24 Thread Yuyang Du
On Mon, May 23, 2016 at 05:42:20PM +0200, Mike Galbraith wrote: > On Mon, 2016-05-23 at 15:10 +0100, Morten Rasmussen wrote: > > On Mon, May 23, 2016 at 03:00:46PM +0200, Mike Galbraith wrote: > > > On Mon, 2016-05-23 at 13:00 +0100, Morten Rasmussen wrote: > > > > > > > The problem then seems to

Re: [PATCH 03/16] sched/fair: Disregard idle task wakee_flips in wake_wide

2016-05-24 Thread Yuyang Du
On Mon, May 23, 2016 at 01:00:10PM +0100, Morten Rasmussen wrote: > On Mon, May 23, 2016 at 01:12:07PM +0200, Mike Galbraith wrote: > > On Mon, 2016-05-23 at 11:58 +0100, Morten Rasmussen wrote: > > > wake_wide() is based on task wakee_flips of the waker and the wakee to > > > decide whether an aff

Re: [PATCH 03/16] sched/fair: Disregard idle task wakee_flips in wake_wide

2016-05-23 Thread Mike Galbraith
On Mon, 2016-05-23 at 15:10 +0100, Morten Rasmussen wrote: > On Mon, May 23, 2016 at 03:00:46PM +0200, Mike Galbraith wrote: > > On Mon, 2016-05-23 at 13:00 +0100, Morten Rasmussen wrote: > > > > > The problem then seems to be distinguishing truly idle and busy doing > > > interrupts. The issue th

Re: [PATCH 03/16] sched/fair: Disregard idle task wakee_flips in wake_wide

2016-05-23 Thread Morten Rasmussen
On Mon, May 23, 2016 at 03:00:46PM +0200, Mike Galbraith wrote: > On Mon, 2016-05-23 at 13:00 +0100, Morten Rasmussen wrote: > > > The problem then seems to be distinguishing truly idle and busy doing > > interrupts. The issue that I observe is that wake_wide() likes pushing > > tasks around in li

Re: [PATCH 03/16] sched/fair: Disregard idle task wakee_flips in wake_wide

2016-05-23 Thread Mike Galbraith
On Mon, 2016-05-23 at 13:00 +0100, Morten Rasmussen wrote: > The problem then seems to be distinguishing truly idle and busy doing > interrupts. The issue that I observe is that wake_wide() likes pushing > tasks around in lightly scenarios which isn't desirable for power > management. Selecting th

Re: [PATCH 03/16] sched/fair: Disregard idle task wakee_flips in wake_wide

2016-05-23 Thread Morten Rasmussen
On Mon, May 23, 2016 at 01:12:07PM +0200, Mike Galbraith wrote: > On Mon, 2016-05-23 at 11:58 +0100, Morten Rasmussen wrote: > > wake_wide() is based on task wakee_flips of the waker and the wakee to > > decide whether an affine wakeup is desirable. On lightly loaded systems > > the waker is freque

Re: [PATCH 03/16] sched/fair: Disregard idle task wakee_flips in wake_wide

2016-05-23 Thread Mike Galbraith
On Mon, 2016-05-23 at 11:58 +0100, Morten Rasmussen wrote: > wake_wide() is based on task wakee_flips of the waker and the wakee to > decide whether an affine wakeup is desirable. On lightly loaded systems > the waker is frequently the idle task (pid=0) which can accumulate a lot > of wakee_flips i

[PATCH 03/16] sched/fair: Disregard idle task wakee_flips in wake_wide

2016-05-23 Thread Morten Rasmussen
wake_wide() is based on task wakee_flips of the waker and the wakee to decide whether an affine wakeup is desirable. On lightly loaded systems the waker is frequently the idle task (pid=0) which can accumulate a lot of wakee_flips in that scenario. It makes little sense to prevent affine wakeups on