[PATCH 10/10] posix-cpu-timers: cleanup cpu_{clock,timer}_sample{,_group}

From: kosaki . motohiro
Date: Mon Apr 29 2013 - 23:19:11 EST


From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>

Now we have similar four timer related functions, cpu_clock_sample(),
cpu_clock_sample_group(), cpu_timer_sample() and cpu_timer_sample_group().

For readability, making do_cpu_clock_timer_sample() and thread_cputime()
helper functions and all *_sample functions use them.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
---
include/linux/sched.h | 1 +
kernel/posix-cpu-timers.c | 132 +++++++++++++++++++-------------------------
kernel/sched/cputime.c | 11 ++++
3 files changed, 69 insertions(+), 75 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 7863d4b..73ac8fa 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2622,6 +2622,7 @@ static inline int spin_needbreak(spinlock_t *lock)
#endif
}

+void thread_cputime(struct task_struct *tsk, bool add_delta, struct task_cputime *times);
/*
* Thread group CPU time accounting.
*/
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 4043282..b33290d 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -203,46 +203,6 @@ posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp)
return error;
}

-
-static int do_cpu_clock_timer_sample(const clockid_t which_clock,
- struct task_struct *p,
- bool add_delta,
- union cpu_time_count *cpu)
-{
- switch (CPUCLOCK_WHICH(which_clock)) {
- default:
- return -EINVAL;
- case CPUCLOCK_PROF:
- cpu->cpu = prof_ticks(p);
- break;
- case CPUCLOCK_VIRT:
- cpu->cpu = virt_ticks(p);
- break;
- case CPUCLOCK_SCHED:
- cpu->sched = task_sched_runtime(p, add_delta);
- break;
- }
- return 0;
-}
-
-/*
- * Sample a per-thread clock for the given task.
- */
-static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p,
- union cpu_time_count *cpu)
-{
- return do_cpu_clock_timer_sample(which_clock, p, true, cpu);
-}
-
-/*
- * Sample a per-thread timer clock for the given task.
- */
-static int cpu_timer_sample(const clockid_t which_clock, struct task_struct *p,
- union cpu_time_count *cpu)
-{
- return do_cpu_clock_timer_sample(which_clock, p, false, cpu);
-}
-
static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b)
{
if (b->utime > a->utime)
@@ -284,34 +244,83 @@ void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
}

/*
- * Sample a process (thread group) clock for the given group_leader task.
- * Must be called with tasklist_lock held for reading.
+ * Sample time for the given task.
+ * @which_clock: Clock id.
+ * @p: Target task. Must be thread group leader when
+ * thread_group is true.
+ * @thread_group: True if want to get process time.
+ * @add_delta: True if want to get clock time,
+ * otherwise, get timer time.
*/
-static int cpu_clock_sample_group(const clockid_t which_clock,
- struct task_struct *p,
- union cpu_time_count *cpu)
+static int do_cpu_clock_timer_sample(const clockid_t which_clock,
+ struct task_struct *p,
+ bool thread_group,
+ bool clock_time,
+ union cpu_time_count *cpu)
{
struct task_cputime cputime;

+ if (thread_group) {
+ if (clock_time)
+ thread_group_cputime(p, true, &cputime);
+ else
+ thread_group_cputimer(p, &cputime);
+ } else
+ thread_cputime(p, clock_time, &cputime);
+
switch (CPUCLOCK_WHICH(which_clock)) {
default:
return -EINVAL;
case CPUCLOCK_PROF:
- thread_group_cputime(p, true, &cputime);
cpu->cpu = cputime.utime + cputime.stime;
break;
case CPUCLOCK_VIRT:
- thread_group_cputime(p, true, &cputime);
cpu->cpu = cputime.utime;
break;
case CPUCLOCK_SCHED:
- thread_group_cputime(p, true, &cputime);
cpu->sched = cputime.sum_exec_runtime;
break;
}
return 0;
}

+/*
+ * Sample a per-thread clock time for the given task.
+ */
+static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p,
+ union cpu_time_count *cpu)
+{
+ return do_cpu_clock_timer_sample(which_clock, p, false, true, cpu);
+}
+
+/*
+ * Sample a per-process clock time for the given task.
+ */
+static int cpu_clock_sample_group(const clockid_t which_clock,
+ struct task_struct *p,
+ union cpu_time_count *cpu)
+{
+ return do_cpu_clock_timer_sample(which_clock, p, true, true, cpu);
+}
+
+/*
+ * Sample a per-thread timer time for the given task.
+ */
+static int cpu_timer_sample(const clockid_t which_clock, struct task_struct *p,
+ union cpu_time_count *cpu)
+{
+ return do_cpu_clock_timer_sample(which_clock, p, false, false, cpu);
+}
+
+/*
+ * Sample a per-process timer time for the given task.
+ */
+static int cpu_timer_sample_group(const clockid_t which_clock,
+ struct task_struct *p,
+ union cpu_time_count *cpu)
+{
+ return do_cpu_clock_timer_sample(which_clock, p, true, false, cpu);
+}

static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
{
@@ -632,33 +641,6 @@ static void cpu_timer_fire(struct k_itimer *timer)
}

/*
- * Sample a process (thread group) timer for the given group_leader task.
- * Must be called with tasklist_lock held for reading.
- */
-static int cpu_timer_sample_group(const clockid_t which_clock,
- struct task_struct *p,
- union cpu_time_count *cpu)
-{
- struct task_cputime cputime;
-
- thread_group_cputimer(p, &cputime);
- switch (CPUCLOCK_WHICH(which_clock)) {
- default:
- return -EINVAL;
- case CPUCLOCK_PROF:
- cpu->cpu = cputime.utime + cputime.stime;
- break;
- case CPUCLOCK_VIRT:
- cpu->cpu = cputime.utime;
- break;
- case CPUCLOCK_SCHED:
- cpu->sched = cputime.sum_exec_runtime;
- break;
- }
- return 0;
-}
-
-/*
* Guts of sys_timer_settime for CPU timers.
* This is called with the timer locked and interrupts disabled.
* If we return TIMER_RETRY, it's necessary to release the timer's lock
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 69d3f6c..29ef7d7 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -289,6 +289,17 @@ static __always_inline bool steal_account_process_tick(void)
return false;
}

+void thread_cputime(struct task_struct *tsk, bool add_delta, struct task_cputime *times)
+{
+ struct signal_struct *sig = tsk->signal;
+ cputime_t utime, stime;
+
+ task_cputime(tsk, &utime, &stime);
+ times->utime = utime;
+ times->stime = stime;
+ times->sum_exec_runtime = task_sched_runtime(tsk, add_delta);
+}
+
/*
* Accumulate raw cputime values of dead tasks (sig->[us]time) and live
* tasks (sum on group iteration) belonging to @tsk's group.
--
1.7.1

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