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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2009-02-05 12:24:16 +0100
committerIngo Molnar <mingo@elte.hu>2009-02-05 13:04:33 +0100
commit4cd4c1b40d40447fb5e7ba80746c6d7ba91d7a53 (patch)
treeb1e580d5284648d6884e951d995509094a92cca4 /kernel/sched_stats.h
parent32bd671d6cbeda60dc73be77fa2b9037d9a9bfa0 (diff)
downloadlinux-4cd4c1b40d40447fb5e7ba80746c6d7ba91d7a53.tar.bz2
timers: split process wide cpu clocks/timers
Change the process wide cpu timers/clocks so that we: 1) don't mess up the kernel with too many threads, 2) don't have a per-cpu allocation for each process, 3) have no impact when not used. In order to accomplish this we're going to split it into two parts: - clocks; which can take all the time they want since they run from user context -- ie. sys_clock_gettime(CLOCK_PROCESS_CPUTIME_ID) - timers; which need constant time sampling but since they're explicity used, the user can pay the overhead. The clock readout will go back to a full sum of the thread group, while the timers will run of a global 'clock' that only runs when needed, so only programs that make use of the facility pay the price. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched_stats.h')
-rw-r--r--kernel/sched_stats.h45
1 files changed, 26 insertions, 19 deletions
diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
index 8ab0cef8ecab..a8f93dd374e1 100644
--- a/kernel/sched_stats.h
+++ b/kernel/sched_stats.h
@@ -296,19 +296,21 @@ sched_info_switch(struct task_struct *prev, struct task_struct *next)
static inline void account_group_user_time(struct task_struct *tsk,
cputime_t cputime)
{
- struct task_cputime *times;
- struct signal_struct *sig;
+ struct thread_group_cputimer *cputimer;
/* tsk == current, ensure it is safe to use ->signal */
if (unlikely(tsk->exit_state))
return;
- sig = tsk->signal;
- times = &sig->cputime.totals;
+ cputimer = &tsk->signal->cputimer;
- spin_lock(&times->lock);
- times->utime = cputime_add(times->utime, cputime);
- spin_unlock(&times->lock);
+ if (!cputimer->running)
+ return;
+
+ spin_lock(&cputimer->lock);
+ cputimer->cputime.utime =
+ cputime_add(cputimer->cputime.utime, cputime);
+ spin_unlock(&cputimer->lock);
}
/**
@@ -324,19 +326,21 @@ static inline void account_group_user_time(struct task_struct *tsk,
static inline void account_group_system_time(struct task_struct *tsk,
cputime_t cputime)
{
- struct task_cputime *times;
- struct signal_struct *sig;
+ struct thread_group_cputimer *cputimer;
/* tsk == current, ensure it is safe to use ->signal */
if (unlikely(tsk->exit_state))
return;
- sig = tsk->signal;
- times = &sig->cputime.totals;
+ cputimer = &tsk->signal->cputimer;
+
+ if (!cputimer->running)
+ return;
- spin_lock(&times->lock);
- times->stime = cputime_add(times->stime, cputime);
- spin_unlock(&times->lock);
+ spin_lock(&cputimer->lock);
+ cputimer->cputime.stime =
+ cputime_add(cputimer->cputime.stime, cputime);
+ spin_unlock(&cputimer->lock);
}
/**
@@ -352,7 +356,7 @@ static inline void account_group_system_time(struct task_struct *tsk,
static inline void account_group_exec_runtime(struct task_struct *tsk,
unsigned long long ns)
{
- struct task_cputime *times;
+ struct thread_group_cputimer *cputimer;
struct signal_struct *sig;
sig = tsk->signal;
@@ -361,9 +365,12 @@ static inline void account_group_exec_runtime(struct task_struct *tsk,
if (unlikely(!sig))
return;
- times = &sig->cputime.totals;
+ cputimer = &sig->cputimer;
+
+ if (!cputimer->running)
+ return;
- spin_lock(&times->lock);
- times->sum_exec_runtime += ns;
- spin_unlock(&times->lock);
+ spin_lock(&cputimer->lock);
+ cputimer->cputime.sum_exec_runtime += ns;
+ spin_unlock(&cputimer->lock);
}