Re: [PATCH v2] tg: show the sum wait time of an task group

[王贇 <yun.wang@linux.alibaba.com>]

On 2018/7/23 下午5:31, Peter Zijlstra wrote:
> On Wed, Jul 04, 2018 at 11:27:27AM +0800, 王贇 wrote:
> 
>> @@ -6788,6 +6790,12 @@ static int cpu_cfs_stat_show(struct seq_file *sf, void *v)
>>   	seq_printf(sf, "nr_throttled %d\n", cfs_b->nr_throttled);
>>   	seq_printf(sf, "throttled_time %llu\n", cfs_b->throttled_time);
>>
>> +	if (schedstat_enabled() && tg != &root_task_group) {
> 
> I put the variables here.

Will do that in next version :-)

> 
>> +		for_each_possible_cpu(i)
>> +			ws += schedstat_val(tg->se[i]->statistics.wait_sum);
> 
> This doesn't quite work on 32bit archs, but I'm not sure I care enough
> to be bothered about that.

Could easily overflow then... hope they won't really care
about the group conflicts.

Regards,
Michael Wang

> 
>> +		seq_printf(sf, "wait_sum %llu\n", ws);
>> +	}