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Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/…
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…linux/kernel/git/tip/linux-2.6-tip

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: fix process time monotonicity
  sched_clock: fix NOHZ interaction
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Linus Torvalds committed Sep 5, 2008
2 parents 1c402c8 + 4904862 commit 7f62186
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Showing 5 changed files with 69 additions and 62 deletions.
59 changes: 0 additions & 59 deletions fs/proc/array.c
Original file line number Diff line number Diff line change
Expand Up @@ -337,65 +337,6 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
return 0;
}

/*
* Use precise platform statistics if available:
*/
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
static cputime_t task_utime(struct task_struct *p)
{
return p->utime;
}

static cputime_t task_stime(struct task_struct *p)
{
return p->stime;
}
#else
static cputime_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;

p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime));
return p->prev_utime;
}

static cputime_t task_stime(struct task_struct *p)
{
clock_t 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) -
cputime_to_clock_t(task_utime(p));

if (stime >= 0)
p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime));

return p->prev_stime;
}
#endif

static cputime_t task_gtime(struct task_struct *p)
{
return p->gtime;
}

static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task, int whole)
{
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4 changes: 4 additions & 0 deletions include/linux/sched.h
Original file line number Diff line number Diff line change
Expand Up @@ -1475,6 +1475,10 @@ static inline void put_task_struct(struct task_struct *t)
__put_task_struct(t);
}

extern cputime_t task_utime(struct task_struct *p);
extern cputime_t task_stime(struct task_struct *p);
extern cputime_t task_gtime(struct task_struct *p);

/*
* Per process flags
*/
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6 changes: 3 additions & 3 deletions kernel/exit.c
Original file line number Diff line number Diff line change
Expand Up @@ -112,9 +112,9 @@ static void __exit_signal(struct task_struct *tsk)
* We won't ever get here for the group leader, since it
* will have been the last reference on the signal_struct.
*/
sig->utime = cputime_add(sig->utime, tsk->utime);
sig->stime = cputime_add(sig->stime, tsk->stime);
sig->gtime = cputime_add(sig->gtime, tsk->gtime);
sig->utime = cputime_add(sig->utime, task_utime(tsk));
sig->stime = cputime_add(sig->stime, task_stime(tsk));
sig->gtime = cputime_add(sig->gtime, task_gtime(tsk));
sig->min_flt += tsk->min_flt;
sig->maj_flt += tsk->maj_flt;
sig->nvcsw += tsk->nvcsw;
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59 changes: 59 additions & 0 deletions kernel/sched.c
Original file line number Diff line number Diff line change
Expand Up @@ -4178,6 +4178,65 @@ void account_steal_time(struct task_struct *p, cputime_t steal)
cpustat->steal = cputime64_add(cpustat->steal, tmp);
}

/*
* Use precise platform statistics if available:
*/
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
cputime_t task_utime(struct task_struct *p)
{
return p->utime;
}

cputime_t task_stime(struct task_struct *p)
{
return p->stime;
}
#else
cputime_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;

p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime));
return p->prev_utime;
}

cputime_t task_stime(struct task_struct *p)
{
clock_t 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) -
cputime_to_clock_t(task_utime(p));

if (stime >= 0)
p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime));

return p->prev_stime;
}
#endif

inline cputime_t task_gtime(struct task_struct *p)
{
return p->gtime;
}

/*
* This function gets called by the timer code, with HZ frequency.
* We call it with interrupts disabled.
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3 changes: 3 additions & 0 deletions kernel/time/tick-sched.c
Original file line number Diff line number Diff line change
Expand Up @@ -162,6 +162,8 @@ void tick_nohz_stop_idle(int cpu)
ts->idle_lastupdate = now;
ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
ts->idle_active = 0;

sched_clock_idle_wakeup_event(0);
}
}

Expand All @@ -177,6 +179,7 @@ static ktime_t tick_nohz_start_idle(struct tick_sched *ts)
}
ts->idle_entrytime = now;
ts->idle_active = 1;
sched_clock_idle_sleep_event();
return now;
}

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