Messages in this thread | | | Subject | Re: [PATCH] taskstats: Add e/u/stime for TGID command | From | ZhangXiao <> | Date | Tue, 7 Mar 2017 09:12:04 +0800 |
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在 2017年03月07日 06:40, Andrew Morton 写道: > On Fri, 3 Mar 2017 10:33:44 +0800 Zhang Xiao <xiao.zhang@windriver.com> wrote: > >> Add elapsed time, user CPU time and system CPU time to >> thread group status request. >> >> --- a/kernel/taskstats.c >> +++ b/kernel/taskstats.c >> @@ -210,6 +210,7 @@ static int fill_stats_for_tgid(pid_t tgid, struct taskstats *stats) >> struct task_struct *tsk, *first; >> unsigned long flags; >> int rc = -ESRCH; >> + u64 delta, utime, stime; >> >> /* >> * Add additional stats from live tasks except zombie thread group >> @@ -238,6 +239,16 @@ static int fill_stats_for_tgid(pid_t tgid, struct taskstats *stats) >> */ >> delayacct_add_tsk(stats, tsk); >> >> + /* calculate task elapsed time in nsec */ >> + delta = ktime_get_ns() - tsk->start_time; >> + /* Convert to micro seconds */ >> + do_div(delta, NSEC_PER_USEC); >> + stats->ac_etime += delta; >> + >> + task_cputime(tsk, &utime, &stime); >> + stats->ac_utime += div_u64(utime, NSEC_PER_USEC); >> + stats->ac_stime += div_u64(stime, NSEC_PER_USEC); >> + >> stats->nvcsw += tsk->nvcsw; >> stats->nivcsw += tsk->nivcsw; >> } while_each_thread(first, tsk); > > hm, OK, we were just leaving these at zero. Seems sane to me. > > It would be more efficient and perhaps more deterministic to sample > ktime just once? >
yes, that makes the code more readable. :-)
Thanks Xiao
> --- a/kernel/taskstats.c~taskstats-add-e-u-stime-for-tgid-command-fix > +++ a/kernel/taskstats.c > @@ -211,6 +211,7 @@ static int fill_stats_for_tgid(pid_t tgi > unsigned long flags; > int rc = -ESRCH; > u64 delta, utime, stime; > + u64 start_time; > > /* > * Add additional stats from live tasks except zombie thread group > @@ -228,6 +229,7 @@ static int fill_stats_for_tgid(pid_t tgi > memset(stats, 0, sizeof(*stats)); > > tsk = first; > + start_time = ktime_get_ns(); > do { > if (tsk->exit_state) > continue; > @@ -240,7 +242,7 @@ static int fill_stats_for_tgid(pid_t tgi > delayacct_add_tsk(stats, tsk); > > /* calculate task elapsed time in nsec */ > - delta = ktime_get_ns() - tsk->start_time; > + delta = start_time - tsk->start_time; > /* Convert to micro seconds */ > do_div(delta, NSEC_PER_USEC); > stats->ac_etime += delta; > _ > >
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