Re: [RFC] sched: nohz_idle_balance

2012-09-13 Thread Rakib Mullick
On 9/13/12, Peter Zijlstra wrote: > On Thu, 2012-09-13 at 08:49 +0200, Mike Galbraith wrote: >> On Thu, 2012-09-13 at 06:11 +0200, Vincent Guittot wrote: > > Well, updating the load statistics on the cpu you're going to balance > seems like a good end to me.. ;-) No point updating the local

Re: [RFC] sched: nohz_idle_balance

2012-09-13 Thread Mike Galbraith
On Thu, 2012-09-13 at 10:19 +0200, Peter Zijlstra wrote: > On Thu, 2012-09-13 at 08:49 +0200, Mike Galbraith wrote: > > On Thu, 2012-09-13 at 06:11 +0200, Vincent Guittot wrote: > > > On tickless system, one CPU runs load balance for all idle CPUs. > > > The cpu_load of this CPU is updated

Re: [RFC] sched: nohz_idle_balance

2012-09-13 Thread Peter Zijlstra
On Thu, 2012-09-13 at 10:45 +0200, Peter Zijlstra wrote: > On Thu, 2012-09-13 at 10:37 +0200, Vincent Guittot wrote: > > > I think you need to present numbers showing benefit. Crawling all over > > > a mostly idle (4096p?) box is decidedly bad thing to do. > > Yeah, but we're already doing that

Re: [RFC] sched: nohz_idle_balance

2012-09-13 Thread Peter Zijlstra
On Thu, 2012-09-13 at 10:37 +0200, Vincent Guittot wrote: > > I think you need to present numbers showing benefit. Crawling all over > > a mostly idle (4096p?) box is decidedly bad thing to do. Yeah, but we're already doing that anyway.. we know nohz idle balance doesn't scale. Venki and Suresh

Re: [RFC] sched: nohz_idle_balance

2012-09-13 Thread Vincent Guittot
Wrong button make me removed others guys from the thread. Sorry for this mistake. On 13 September 2012 09:56, Mike Galbraith wrote: > On Thu, 2012-09-13 at 09:44 +0200, Vincent Guittot wrote: >> On 13 September 2012 09:29, Mike Galbraith wrote: >> > On Thu, 2012-09-13 at 08:59 +0200, Vincent

Re: [RFC] sched: nohz_idle_balance

2012-09-13 Thread Peter Zijlstra
On Thu, 2012-09-13 at 06:11 +0200, Vincent Guittot wrote: > On tickless system, one CPU runs load balance for all idle CPUs. > The cpu_load of this CPU is updated before starting the load balance > of each other idle CPUs. We should instead update the cpu_load of the > balance_cpu. > >

Re: [RFC] sched: nohz_idle_balance

2012-09-13 Thread Peter Zijlstra
On Thu, 2012-09-13 at 08:49 +0200, Mike Galbraith wrote: > On Thu, 2012-09-13 at 06:11 +0200, Vincent Guittot wrote: > > On tickless system, one CPU runs load balance for all idle CPUs. > > The cpu_load of this CPU is updated before starting the load balance > > of each other idle CPUs. We should

Re: [RFC] sched: nohz_idle_balance

2012-09-13 Thread Mike Galbraith
On Thu, 2012-09-13 at 06:11 +0200, Vincent Guittot wrote: > On tickless system, one CPU runs load balance for all idle CPUs. > The cpu_load of this CPU is updated before starting the load balance > of each other idle CPUs. We should instead update the cpu_load of the > balance_cpu. > >

Re: [RFC] sched: nohz_idle_balance

2012-09-13 Thread Mike Galbraith
On Thu, 2012-09-13 at 06:11 +0200, Vincent Guittot wrote: On tickless system, one CPU runs load balance for all idle CPUs. The cpu_load of this CPU is updated before starting the load balance of each other idle CPUs. We should instead update the cpu_load of the balance_cpu. Signed-off-by:

Re: [RFC] sched: nohz_idle_balance

2012-09-13 Thread Peter Zijlstra
On Thu, 2012-09-13 at 08:49 +0200, Mike Galbraith wrote: On Thu, 2012-09-13 at 06:11 +0200, Vincent Guittot wrote: On tickless system, one CPU runs load balance for all idle CPUs. The cpu_load of this CPU is updated before starting the load balance of each other idle CPUs. We should

Re: [RFC] sched: nohz_idle_balance

2012-09-13 Thread Peter Zijlstra
On Thu, 2012-09-13 at 06:11 +0200, Vincent Guittot wrote: On tickless system, one CPU runs load balance for all idle CPUs. The cpu_load of this CPU is updated before starting the load balance of each other idle CPUs. We should instead update the cpu_load of the balance_cpu. Signed-off-by:

Re: [RFC] sched: nohz_idle_balance

2012-09-13 Thread Vincent Guittot
Wrong button make me removed others guys from the thread. Sorry for this mistake. On 13 September 2012 09:56, Mike Galbraith efa...@gmx.de wrote: On Thu, 2012-09-13 at 09:44 +0200, Vincent Guittot wrote: On 13 September 2012 09:29, Mike Galbraith efa...@gmx.de wrote: On Thu, 2012-09-13 at

Re: [RFC] sched: nohz_idle_balance

2012-09-13 Thread Peter Zijlstra
On Thu, 2012-09-13 at 10:37 +0200, Vincent Guittot wrote: I think you need to present numbers showing benefit. Crawling all over a mostly idle (4096p?) box is decidedly bad thing to do. Yeah, but we're already doing that anyway.. we know nohz idle balance doesn't scale. Venki and Suresh

Re: [RFC] sched: nohz_idle_balance

2012-09-13 Thread Peter Zijlstra
On Thu, 2012-09-13 at 10:45 +0200, Peter Zijlstra wrote: On Thu, 2012-09-13 at 10:37 +0200, Vincent Guittot wrote: I think you need to present numbers showing benefit. Crawling all over a mostly idle (4096p?) box is decidedly bad thing to do. Yeah, but we're already doing that anyway..

Re: [RFC] sched: nohz_idle_balance

2012-09-13 Thread Mike Galbraith
On Thu, 2012-09-13 at 10:19 +0200, Peter Zijlstra wrote: On Thu, 2012-09-13 at 08:49 +0200, Mike Galbraith wrote: On Thu, 2012-09-13 at 06:11 +0200, Vincent Guittot wrote: On tickless system, one CPU runs load balance for all idle CPUs. The cpu_load of this CPU is updated before

Re: [RFC] sched: nohz_idle_balance

2012-09-13 Thread Rakib Mullick
On 9/13/12, Peter Zijlstra pet...@infradead.org wrote: On Thu, 2012-09-13 at 08:49 +0200, Mike Galbraith wrote: On Thu, 2012-09-13 at 06:11 +0200, Vincent Guittot wrote: Well, updating the load statistics on the cpu you're going to balance seems like a good end to me.. ;-) No point updating

[RFC] sched: nohz_idle_balance

2012-09-12 Thread Vincent Guittot
On tickless system, one CPU runs load balance for all idle CPUs. The cpu_load of this CPU is updated before starting the load balance of each other idle CPUs. We should instead update the cpu_load of the balance_cpu. Signed-off-by: Vincent Guittot --- kernel/sched/fair.c | 11 ++- 1

[RFC] sched: nohz_idle_balance

2012-09-12 Thread Vincent Guittot
On tickless system, one CPU runs load balance for all idle CPUs. The cpu_load of this CPU is updated before starting the load balance of each other idle CPUs. We should instead update the cpu_load of the balance_cpu. Signed-off-by: Vincent Guittot vincent.guit...@linaro.org ---