Re: [RFC V2 2/2] sched/fair: Fallback to sched-idle CPU if idle CPU isn't found

2019-06-03 Thread Viresh Kumar
On 25-04-19, 15:07, Viresh Kumar wrote: > We target for an idle CPU in select_idle_sibling() to run the next task, > but in case we don't find idle CPUs it is better to pick a CPU which > will run the task the soonest, for performance reason. A CPU which isn't > idle but has only SCHED_IDLE

Re: [RFC V2 2/2] sched/fair: Fallback to sched-idle CPU if idle CPU isn't found

2019-05-14 Thread Subhra Mazumdar
On 5/14/19 10:27 AM, Subhra Mazumdar wrote: On 5/14/19 9:03 AM, Steven Sistare wrote: On 5/13/2019 7:35 AM, Peter Zijlstra wrote: On Mon, May 13, 2019 at 03:04:18PM +0530, Viresh Kumar wrote: On 10-05-19, 09:21, Peter Zijlstra wrote: I don't hate his per se; but the whole

Re: [RFC V2 2/2] sched/fair: Fallback to sched-idle CPU if idle CPU isn't found

2019-05-14 Thread Subhra Mazumdar
On 5/14/19 9:03 AM, Steven Sistare wrote: On 5/13/2019 7:35 AM, Peter Zijlstra wrote: On Mon, May 13, 2019 at 03:04:18PM +0530, Viresh Kumar wrote: On 10-05-19, 09:21, Peter Zijlstra wrote: I don't hate his per se; but the whole select_idle_sibling() thing is something that needs looking

Re: [RFC V2 2/2] sched/fair: Fallback to sched-idle CPU if idle CPU isn't found

2019-05-14 Thread Steven Sistare
On 5/13/2019 7:35 AM, Peter Zijlstra wrote: > On Mon, May 13, 2019 at 03:04:18PM +0530, Viresh Kumar wrote: >> On 10-05-19, 09:21, Peter Zijlstra wrote: > >>> I don't hate his per se; but the whole select_idle_sibling() thing is >>> something that needs looking at. >>> >>> There was the task

Re: [RFC V2 2/2] sched/fair: Fallback to sched-idle CPU if idle CPU isn't found

2019-05-13 Thread Peter Zijlstra
On Mon, May 13, 2019 at 03:04:18PM +0530, Viresh Kumar wrote: > On 10-05-19, 09:21, Peter Zijlstra wrote: > > I don't hate his per se; but the whole select_idle_sibling() thing is > > something that needs looking at. > > > > There was the task stealing thing from Steve that looked interesting

Re: [RFC V2 2/2] sched/fair: Fallback to sched-idle CPU if idle CPU isn't found

2019-05-13 Thread Viresh Kumar
On 10-05-19, 09:21, Peter Zijlstra wrote: > On Thu, Apr 25, 2019 at 03:07:40PM +0530, Viresh Kumar wrote: > > We target for an idle CPU in select_idle_sibling() to run the next task, > > but in case we don't find idle CPUs it is better to pick a CPU which > > will run the task the soonest, for

Re: [RFC V2 2/2] sched/fair: Fallback to sched-idle CPU if idle CPU isn't found

2019-05-10 Thread Peter Zijlstra
On Thu, Apr 25, 2019 at 03:07:40PM +0530, Viresh Kumar wrote: > We target for an idle CPU in select_idle_sibling() to run the next task, > but in case we don't find idle CPUs it is better to pick a CPU which > will run the task the soonest, for performance reason. A CPU which isn't > idle but has

[RFC V2 2/2] sched/fair: Fallback to sched-idle CPU if idle CPU isn't found

2019-04-25 Thread Viresh Kumar
We target for an idle CPU in select_idle_sibling() to run the next task, but in case we don't find idle CPUs it is better to pick a CPU which will run the task the soonest, for performance reason. A CPU which isn't idle but has only SCHED_IDLE activity queued on it should be a good target based on