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| author | Ingo Molnar <mingo@elte.hu> | 2007-07-09 18:51:59 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2007-07-09 18:51:59 +0200 |
| commit | b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa (patch) | |
| tree | 37b918b7dcc548671db53d4f3c2fdc673939e086 /fs/proc/array.c | |
| parent | 1b9f19c2125dd1021b9327111dc40b14b557ee12 (diff) | |
| download | linux-b27f03d4bdc145a09fb7b0c0e004b29f1ee555fa.tar.gz | |
sched: make use of precise accounting for /proc task stats
make use of CFS's precise accounting to drive /proc/<pid>/stat statistics. this code was co-authored by: Balbir Singh <balbir@linux.vnet.ibm.com> Dmitry Adamushko <dmitry.adamushko@gmail.com> Ingo Molnar <mingo@elte.hu> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Diffstat (limited to 'fs/proc/array.c')
| -rw-r--r-- | fs/proc/array.c | 57 |
1 files changed, 47 insertions, 10 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c index 3df644313f9b..98e78e2f18d6 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -310,6 +310,41 @@ int proc_pid_status(struct task_struct *task, char * buffer) return buffer - orig; } +static clock_t task_utime(struct task_struct *p) +{ + clock_t utime = cputime_to_clock_t(p->utime), + total = utime + cputime_to_clock_t(p->stime); + u64 temp; + + /* + * Use CFS's precise accounting: + */ + temp = (u64)nsec_to_clock_t(p->se.sum_exec_runtime); + + if (total) { + temp *= utime; + do_div(temp, total); + } + utime = (clock_t)temp; + + return utime; +} + +static clock_t task_stime(struct task_struct *p) +{ + clock_t stime = cputime_to_clock_t(p->stime); + + /* + * Use CFS's precise accounting. (we subtract utime from + * the total, to make sure the total observed by userspace + * grows monotonically - apps rely on that): + */ + stime = nsec_to_clock_t(p->se.sum_exec_runtime) - task_utime(p); + + return stime; +} + + static int do_task_stat(struct task_struct *task, char * buffer, int whole) { unsigned long vsize, eip, esp, wchan = ~0UL; @@ -324,7 +359,8 @@ static int do_task_stat(struct task_struct *task, char * buffer, int whole) unsigned long long start_time; unsigned long cmin_flt = 0, cmaj_flt = 0; unsigned long min_flt = 0, maj_flt = 0; - cputime_t cutime, cstime, utime, stime; + cputime_t cutime, cstime; + clock_t utime, stime; unsigned long rsslim = 0; char tcomm[sizeof(task->comm)]; unsigned long flags; @@ -342,7 +378,8 @@ static int do_task_stat(struct task_struct *task, char * buffer, int whole) sigemptyset(&sigign); sigemptyset(&sigcatch); - cutime = cstime = utime = stime = cputime_zero; + cutime = cstime = cputime_zero; + utime = stime = 0; rcu_read_lock(); if (lock_task_sighand(task, &flags)) { @@ -368,15 +405,15 @@ static int do_task_stat(struct task_struct *task, char * buffer, int whole) do { min_flt += t->min_flt; maj_flt += t->maj_flt; - utime = cputime_add(utime, t->utime); - stime = cputime_add(stime, t->stime); + utime += task_utime(t); + stime += task_stime(t); t = next_thread(t); } while (t != task); min_flt += sig->min_flt; maj_flt += sig->maj_flt; - utime = cputime_add(utime, sig->utime); - stime = cputime_add(stime, sig->stime); + utime += cputime_to_clock_t(sig->utime); + stime += cputime_to_clock_t(sig->stime); } sid = signal_session(sig); @@ -392,8 +429,8 @@ static int do_task_stat(struct task_struct *task, char * buffer, int whole) if (!whole) { min_flt = task->min_flt; maj_flt = task->maj_flt; - utime = task->utime; - stime = task->stime; + utime = task_utime(task); + stime = task_stime(task); } /* scale priority and nice values from timeslices to -20..20 */ @@ -424,8 +461,8 @@ static int do_task_stat(struct task_struct *task, char * buffer, int whole) cmin_flt, maj_flt, cmaj_flt, - cputime_to_clock_t(utime), - cputime_to_clock_t(stime), + utime, + stime, cputime_to_clock_t(cutime), cputime_to_clock_t(cstime), priority, |