Re: [PATCH 2/3] sched,fair: Fix local starvation

From: Wanpeng Li
Date: Sun May 22 2016 - 02:51:13 EST


2016-05-21 22:04 GMT+08:00 Mike Galbraith <mgalbraith@xxxxxxx>:
> On Tue, 2016-05-10 at 19:43 +0200, Peter Zijlstra wrote:
>
> (Evolution authors must either not do patch review, or use some other
> mailer. Squint hard, this crud really is your patch;)
>
>> --- a/kernel/sched/core.c
>> +++ b/kernel/sched/core.c
>>
>> @@ -1762,7 +1770,11 @@ void sched_ttwu_pending(void)
>> > > while (llist) {
>> > > > p = llist_entry(llist, struct task_struct, wake_entry);
>> > > > llist = llist_next(llist);
>> -> > > ttwu_do_activate(rq, p, 0, cookie);
>> +> > > /*
>> +> > > * See ttwu_queue(); we only call ttwu_queue_remote() when
>> +> > > * its a x-cpu wakeup.
>> +> > > */
>> +> > > ttwu_do_activate(rq, p, WF_MIGRATED, cookie);
>
> Wakees that were not migrated/normalized eat an unwanted min_vruntime,

Why there were wakees queued by twu_queue_remote() not migrated?

Regards,
Wanpeng Li