Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH v2] tg: show the sum wait time of an task group
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     Ingo Molnar <mingo@redhat.com>, linux-kernel@vger.kernel.org
References: <5c4c978d-e8fb-4bcb-b942-3c6d3dcfc13e@linux.alibaba.com>
 <b9e74571-87d0-ef27-3f14-ebd21d72ee15@linux.alibaba.com>
 <ff7dae3b-e5f9-7157-1caa-ff02c6b23dc1@linux.alibaba.com>
 <20180723093121.GA2494@hirez.programming.kicks-ass.net>
From:   =?UTF-8?B?546L6LSH?= <yun.wang@linux.alibaba.com>
Message-ID: <a57d74eb-f7a8-80e6-6798-2f9eec942ce3@linux.alibaba.com>
Date:   Mon, 23 Jul 2018 20:32:14 +0800
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:52.0)
 Gecko/20100101 Thunderbird/52.8.0
MIME-Version: 1.0
In-Reply-To: <20180723093121.GA2494@hirez.programming.kicks-ass.net>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


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);
>> +	}