On 28 November 2016 at 18:01, Matt Fleming <m...@codeblueprint.co.uk> wrote: > On Fri, 25 Nov, at 04:34:32PM, Vincent Guittot wrote: >> >> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c >> index aa47589..820a787 100644 >> --- a/kernel/sched/fair.c >> +++ b/kernel/sched/fair.c >> @@ -5463,13 +5463,19 @@ find_idlest_group(struct sched_domain *sd, struct >> task_struct *p, >> * utilized systems if we require spare_capacity > task_util(p), >> * so we allow for some task stuffing by using >> * spare_capacity > task_util(p)/2. >> + * spare capacity can't be used for fork because the utilization has >> + * not been set yet as it need to get a rq to init the utilization >> */ >> + if (sd_flag & SD_BALANCE_FORK) >> + goto no_spare; >> + >> if (this_spare > task_util(p) / 2 && >> imbalance*this_spare > 100*most_spare) >> return NULL; >> else if (most_spare > task_util(p) / 2) >> return most_spare_sg; >> >> +no_spare: >> if (!idlest || 100*this_load < imbalance*min_load) >> return NULL; >> return idlest; > > It's only a minor comment, but would you be opposed to calling this > label 'skip_spare' to indicate that spare capacity may exist, but > we're not going to make use of it?
you're right, 'skip_spare' makes more sense
