Guillaume Chazarain wrote:
> Le Mon, 20 Aug 2007 22:31:08 +0530,
> Balbir Singh <[EMAIL PROTECTED]> a écrit :
>
>>> --- a/kernel/taskstats.c Sat Aug 18 17:15:17 2007 -0700
>>> +++ b/kernel/taskstats.c Sun Aug 19 17:20:15 2007 +0200
>>> @@ -246,6 +246,8 @@ static int fill_tgid(pid_t tgid, struct
>>>
>>> stats->nvcsw += tsk->nvcsw;
>>> stats->nivcsw += tsk->nivcsw;
>>> + bacct_add_tsk(stats, tsk);
>>> + xacct_add_tsk(stats, tsk);
>> I'm afraid this is still not good enough. bacct_add_tsk() will assign
>> values and do nothing in the loop (HINT: no summation).
>
> Hi Balbir, thank you for your review. I agree with everything you said
> and am on my way to do it as time permits, but I have some trouble
> understanding this part. You stated that bacct_add_tsk() would overwrite
> the stats of each thread in the tgid stats, but the other part of the
> patch is the (actually wrong) combination of stats in xxx_add_tsk()
> using min/max/sum.
>
Hi, Guillaume,
The CSA code was written by Jay Lan, but I'll see if I can answer your
questions. In the current implementation, CSA does not use TGID exit
notifications. In fill_pid(), both bacct_add_tsk() and xacct_add_tsk()
are called (which is correct), they complement each other.
The code needs refactoring to ensure that they can work together
in the fill_tgid() scenario.
> Also, I don't understand why the code to update btime:
>
> /* calculate task elapsed time in timespec */
> do_posix_clock_monotonic_gettime(&uptime);
> ts = timespec_sub(uptime, tsk->start_time);
> ...
> stats->ac_btime = get_seconds() - ts.tv_sec;
>
> does not simply use tsk->start_time or tsk->real_start_time without
> comparing it to the current time.
>
>From what I understand, task->start_time and task->real_start_time
are taken from the realtime clock. The accounting in CSA seems
to be very similar to the accounting done in do_acct_process()
(kernel/acct.c).
Jay/Jonathan any comments?
--
Warm Regards,
Balbir Singh
Linux Technology Center
IBM, ISTL
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