Re: [PATCH 2/2] sched/deadline: don't need to balance during wakeup if wakee is pinned

From: Juri Lelli
Date: Tue Oct 21 2014 - 09:29:32 EST


Hi,

On 21/10/14 13:19, Wanpeng Li wrote:
> Cc Juri,
>
> ä 10/14/14, 10:22 AM, Wanpeng Li åé:
>> Use nr_cpus_allowed to bail from select_task_rq() when only one cpu
>> can be used, and saves some cycles for pinned tasks.
>>
>> Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxxxxxx>
>> ---
>> kernel/sched/deadline.c | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
>> index f46b7f1..5874bf8 100644
>> --- a/kernel/sched/deadline.c
>> +++ b/kernel/sched/deadline.c
>> @@ -914,6 +914,9 @@ select_task_rq_dl(struct task_struct *p, int cpu, int sd_flag, int flags)
>> struct task_struct *curr;
>> struct rq *rq;
>>
>> + if (p->nr_cpus_allowed == 1)
>> + goto out;
>> +
>> if (sd_flag != SD_BALANCE_WAKE)
>> goto out;
>>

Apart from the encoding of the resend, it looks good, thanks!

Best,

- Juri

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