Re: [PATCH] exit,stats: /* obey this comment */

[Rik van Riel <riel@redhat.com>]

On 04/23/2015 05:47 PM, Andrew Morton wrote:
> On Thu, 23 Apr 2015 17:17:59 -0400 Rik van Riel <riel@redhat.com> wrote:
> 
>> There is a helpful comment in do_exit() that states we sync the
>> mm's RSS info before statistics gathering.
>>
>> The function that does the statistics gathering is called right
>> above that comment.
>>
>> Change the code to obey the comment.
>>
>> ...
>>
>> --- a/kernel/exit.c
>> +++ b/kernel/exit.c
>> @@ -711,10 +711,10 @@ void do_exit(long code)
>>  			current->comm, task_pid_nr(current),
>>  			preempt_count());
>>  
>> -	acct_update_integrals(tsk);
>>  	/* sync mm's RSS info before statistics gathering */
>>  	if (tsk->mm)
>>  		sync_mm_rss(tsk->mm);
>> +	acct_update_integrals(tsk);
>>  	group_dead = atomic_dec_and_test(&tsk->signal->live);
>>  	if (group_dead) {
>>  		hrtimer_cancel(&tsk->signal->real_timer);
> 
> I can't actually find anywhere where these counters are used in the
> accounting code.

Don't the get reported to userspace in things like this?

$ /usr/bin/time ls /dev
...
0.00user 0.00system 0:00.00elapsed 33%CPU (0avgtext+0avgdata
2652maxresident)k
0inputs+0outputs (0major+135minor)pagefaults 0swaps

Though admittedly this thing only reports maxresident...

I think there is some tool that reports the avg resident rss,
but I cannot remember what it is.

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