On Mon, Aug 03, 2020 at 05:06:14PM -0700, Josh Don wrote:
> SMT siblings share caches, so cache hotness should be irrelevant for
> cross-sibling migration.
>
> Proposed-by: Venkatesh Pallipadi <ve...@google.com>
> Signed-off-by: Josh Don <josh...@google.com>
> ---
> kernel/sched/fair.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 2ba8f230feb9..5b203b55bcb2 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -7402,6 +7402,9 @@ static int task_hot(struct task_struct *p, struct
> lb_env *env)
> if (unlikely(task_has_idle_policy(p)))
> return 0;
>
> + if ((env->sd->flags & cpu_smt_flags()) == cpu_smt_flags())
> + return 0;
I think that wants to be:
if (env->sd->flags & SD_SHARE_CPUCAPACITY)
Also, perhaps stick a comment on top with the rationale for this.
> +
> /*
> * Buddy candidates are cache hot:
> */
> --
> 2.28.0.163.g6104cc2f0b6-goog
>
