Re: [PATCH] sched/fair: Clear SMT siblings after determining the core is not idle

2020-12-01 Thread Peter Zijlstra
On Mon, Nov 30, 2020 at 03:47:01PM +0100, Vincent Guittot wrote: > On Mon, 30 Nov 2020 at 15:40, Mel Gorman wrote: > > > > The clearing of SMT siblings from the SIS mask before checking for an idle > > core is a small but unnecessary cost. Defer the clearing of the siblings > > until the scan move

Re: [PATCH] sched/fair: Clear SMT siblings after determining the core is not idle

2020-11-30 Thread Li, Aubrey
On 2020/11/30 22:47, Vincent Guittot wrote: > On Mon, 30 Nov 2020 at 15:40, Mel Gorman wrote: >> >> The clearing of SMT siblings from the SIS mask before checking for an idle >> core is a small but unnecessary cost. Defer the clearing of the siblings >> until the scan moves to the next potential t

Re: [PATCH] sched/fair: Clear SMT siblings after determining the core is not idle

2020-11-30 Thread Vincent Guittot
On Mon, 30 Nov 2020 at 15:40, Mel Gorman wrote: > > The clearing of SMT siblings from the SIS mask before checking for an idle > core is a small but unnecessary cost. Defer the clearing of the siblings > until the scan moves to the next potential target. The cost of this was > not measured as it i

[PATCH] sched/fair: Clear SMT siblings after determining the core is not idle

2020-11-30 Thread Mel Gorman
The clearing of SMT siblings from the SIS mask before checking for an idle core is a small but unnecessary cost. Defer the clearing of the siblings until the scan moves to the next potential target. The cost of this was not measured as it is borderline noise but it should be self-evident. Signed-o