Re: [PATCH v4 6/6] sched/fair: Consider SMT in ASYM_PACKING load balance

2021-08-28 Thread Vincent Guittot
On Fri, 27 Aug 2021 at 21:45, Ricardo Neri wrote: > > On Fri, Aug 27, 2021 at 12:13:42PM +0200, Vincent Guittot wrote: > > On Tue, 10 Aug 2021 at 16:41, Ricardo Neri > > wrote: > > > @@ -9540,6 +9629,12 @@ static struct rq *find_busiest_queue(struct lb_env > > > *env, > > > n

Re: [PATCH v4 6/6] sched/fair: Consider SMT in ASYM_PACKING load balance

2021-08-27 Thread Ricardo Neri
On Fri, Aug 27, 2021 at 12:13:42PM +0200, Vincent Guittot wrote: > On Tue, 10 Aug 2021 at 16:41, Ricardo Neri > wrote: > > @@ -9540,6 +9629,12 @@ static struct rq *find_busiest_queue(struct lb_env > > *env, > > nr_running == 1) > > continue; > > > > +

Re: [PATCH v4 6/6] sched/fair: Consider SMT in ASYM_PACKING load balance

2021-08-27 Thread Ricardo Neri
On Fri, Aug 27, 2021 at 05:17:22PM +0200, Vincent Guittot wrote: > On Fri, 27 Aug 2021 at 16:50, Peter Zijlstra wrote: > > > > On Fri, Aug 27, 2021 at 12:13:42PM +0200, Vincent Guittot wrote: > > > > +/** > > > > + * asym_smt_can_pull_tasks - Check whether the load balancing CPU can > > > > pull

Re: [PATCH v4 6/6] sched/fair: Consider SMT in ASYM_PACKING load balance

2021-08-27 Thread Vincent Guittot
On Fri, 27 Aug 2021 at 16:50, Peter Zijlstra wrote: > > On Fri, Aug 27, 2021 at 12:13:42PM +0200, Vincent Guittot wrote: > > > +/** > > > + * asym_smt_can_pull_tasks - Check whether the load balancing CPU can > > > pull tasks > > > + * @dst_cpu: Destination CPU of the load balancing > > > + * @

Re: [PATCH v4 6/6] sched/fair: Consider SMT in ASYM_PACKING load balance

2021-08-27 Thread Peter Zijlstra
On Fri, Aug 27, 2021 at 12:13:42PM +0200, Vincent Guittot wrote: > > +/** > > + * asym_smt_can_pull_tasks - Check whether the load balancing CPU can pull > > tasks > > + * @dst_cpu: Destination CPU of the load balancing > > + * @sds: Load-balancing data with statistics of the local group >

Re: [PATCH v4 6/6] sched/fair: Consider SMT in ASYM_PACKING load balance

2021-08-27 Thread Vincent Guittot
On Tue, 10 Aug 2021 at 16:41, Ricardo Neri wrote: > > When deciding to pull tasks in ASYM_PACKING, it is necessary not only to > check for the idle state of the destination CPU, dst_cpu, but also of > its SMT siblings. > > If dst_cpu is idle but its SMT siblings are busy, performance suffers > if

[PATCH v4 6/6] sched/fair: Consider SMT in ASYM_PACKING load balance

2021-08-10 Thread Ricardo Neri
When deciding to pull tasks in ASYM_PACKING, it is necessary not only to check for the idle state of the destination CPU, dst_cpu, but also of its SMT siblings. If dst_cpu is idle but its SMT siblings are busy, performance suffers if it pulls tasks from a medium priority CPU that does not have SMT