On Mon, May 28, 2007 at 01:07:48PM +0200, Ingo Molnar wrote:
>
> * Balbir Singh <[EMAIL PROTECTED]> wrote:
>
> > Ingo Molnar wrote:
> > > i found an accounting bug in this: it didnt sum up threads correctly.
> > > The patch below fixes this. The stime == 0 problem is still there
> > > though.
> > >
> > > Ingo
> > >
> >
> > Thanks! I'll test the code on Monday. I do not understand the
> > sysctl_sched_smoothing functionality, so I do not understand its
> > impact on accounting. I'll take a look more closely
>
> basically sysctl_sched_smoothing is more of a 'experimental features
> flag' kind of thing. I'll remove it soon, you should only need to
> concentrate on the functionality that it enables by default.
>
> Ingo
Hi, Ingo,
I hope this patch addresses the stime == 0 problem.
This patch improves accounting of the CFS scheduler. We have the executed
run time in sum_exec_runtime field of the task. This patch splits the
sum_exec_runtime in the ratio of task->utime and task->stime to obtain
the user and system time of the task.
TODO's:
1. Migrate getrusage() to use sum_exec_runtime so that the output in /proc
is consistent with the data by running time(1).
Signed-off-by: Balbir Singh <[EMAIL PROTECTED]>
---
fs/proc/array.c | 27 ++++++++++++++++++++++++---
linux/sched.h | 0
2 files changed, 24 insertions(+), 3 deletions(-)
diff -puN fs/proc/array.c~cfs-distribute-accounting fs/proc/array.c
--- linux-2.6.22-rc2/fs/proc/array.c~cfs-distribute-accounting 2007-05-29
13:47:47.000000000 +0530
+++ linux-2.6.22-rc2-balbir/fs/proc/array.c 2007-05-29 15:35:22.000000000
+0530
@@ -332,7 +332,6 @@ static clock_t task_stime(struct task_st
return cputime_to_clock_t(p->stime);
}
-
static int do_task_stat(struct task_struct *task, char * buffer, int whole)
{
unsigned long vsize, eip, esp, wchan = ~0UL;
@@ -400,8 +399,13 @@ static int do_task_stat(struct task_stru
min_flt += sig->min_flt;
maj_flt += sig->maj_flt;
- utime += cputime_to_clock_t(sig->utime);
- stime += cputime_to_clock_t(sig->stime);
+ if (!has_rt_policy(t))
+ utime += nsec_to_clock_t(
+ sig->sum_sched_runtime);
+ else {
+ utime += cputime_to_clock_t(sig->utime);
+ stime += cputime_to_clock_t(sig->stime);
+ }
}
sid = signal_session(sig);
@@ -421,6 +425,23 @@ static int do_task_stat(struct task_stru
stime = task_stime(task);
}
+ if (!has_rt_policy(task)) {
+ clock_t sum_us_time = utime + stime;
+ clock_t tu_time = cputime_to_clock_t(task->utime);
+ clock_t ts_time = cputime_to_clock_t(task->stime);
+ clock_t total_time = utime;
+
+ /*
+ * Split up sched_exec_time according to the utime and
+ * stime ratio. At this point utime contains the summed
+ * sched_exec_runtime and stime is zero
+ */
+ if (sum_us_time) {
+ utime = ((tu_time * total_time) / sum_us_time);
+ stime = ((ts_time * total_time) / sum_us_time);
+ }
+ }
+
/* scale priority and nice values from timeslices to -20..20 */
/* to make it look like a "normal" Unix priority/nice value */
priority = task_prio(task);
diff -puN kernel/sys.c~cfs-distribute-accounting kernel/sys.c
diff -puN include/linux/sched.h~cfs-distribute-accounting include/linux/sched.h
_
--
Warm Regards,
Balbir Singh
Linux Technology Center
IBM, ISTL
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