Messages in this thread | | | From | Josh Don <> | Date | Tue, 4 Aug 2020 12:24:43 -0700 | Subject | Re: [PATCH] sched/fair: ignore cache hotness for SMT migration |
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On Tue, Aug 4, 2020 at 3:56 AM <peterz@infradead.org> wrote: > > 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 <venki@google.com> > > Signed-off-by: Josh Don <joshdon@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) >
Agreed
> Also, perhaps stick a comment on top with the rationale for this. > > > + > > /* > > * Buddy candidates are cache hot: > > */ > > -- > > 2.28.0.163.g6104cc2f0b6-goog > >
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