[PATCH 3/4] nohz: Consolidate sleep time stats read code
From: Frederic Weisbecker
Date: Thu Aug 08 2013 - 20:55:34 EST
get_cpu_idle_time_us() and get_cpu_iowait_time_us() mostly share
the same code. Lets consolidate both implementations.
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Fernando Luis Vazquez Cao <fernando_b1@xxxxxxxxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
---
kernel/time/tick-sched.c | 76 ++++++++++++++++++++--------------------------
1 files changed, 33 insertions(+), 43 deletions(-)
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index f7fc27b..017bec2 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -440,24 +440,10 @@ static ktime_t tick_nohz_start_idle(int cpu, struct tick_sched *ts)
return now;
}
-/**
- * get_cpu_idle_time_us - get the total idle time of a cpu
- * @cpu: CPU number to query
- * @last_update_time: variable to store update time in. Do not update
- * counters if NULL.
- *
- * Return the cummulative idle time (since boot) for a given
- * CPU, in microseconds.
- *
- * This time is measured via accounting rather than sampling,
- * and is as accurate as ktime_get() is.
- *
- * This function returns -1 if NOHZ is not enabled.
- */
-u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time)
+static u64 get_cpu_sleep_time_us(int cpu, bool io, u64 *last_update_time)
{
struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
- ktime_t now, idle;
+ ktime_t now, sleep;
unsigned int seq;
if (!tick_nohz_enabled)
@@ -469,16 +455,41 @@ u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time)
do {
seq = read_seqcount_begin(&ts->sleeptime_seq);
- if (ts->idle_active && !nr_iowait_cpu(cpu)) {
+ if (io)
+ sleep = ts->iowait_sleeptime;
+ else
+ sleep = ts->idle_sleeptime;
+
+ if (ts->idle_active)
+ continue;
+
+ if ((io && nr_iowait_cpu(cpu)) || (!io && !nr_iowait_cpu(cpu))) {
ktime_t delta = ktime_sub(now, ts->idle_entrytime);
- idle = ktime_add(ts->idle_sleeptime, delta);
- } else {
- idle = ts->idle_sleeptime;
+ sleep = ktime_add(sleep, delta);
}
} while (read_seqcount_retry(&ts->sleeptime_seq, seq));
- return ktime_to_us(idle);
+ return ktime_to_us(sleep);
+
+}
+/**
+ * get_cpu_idle_time_us - get the total idle time of a cpu
+ * @cpu: CPU number to query
+ * @last_update_time: variable to store update time in. Do not update
+ * counters if NULL.
+ *
+ * Return the cummulative idle time (since boot) for a given
+ * CPU, in microseconds.
+ *
+ * This time is measured via accounting rather than sampling,
+ * and is as accurate as ktime_get() is.
+ *
+ * This function returns -1 if NOHZ is not enabled.
+ */
+u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time)
+{
+ return get_cpu_sleep_time_us(cpu, false, last_update_time);
}
EXPORT_SYMBOL_GPL(get_cpu_idle_time_us);
@@ -498,28 +509,7 @@ EXPORT_SYMBOL_GPL(get_cpu_idle_time_us);
*/
u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time)
{
- struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
- ktime_t now, iowait;
- unsigned int seq;
-
- if (!tick_nohz_enabled)
- return -1;
-
- now = ktime_get();
- if (last_update_time)
- *last_update_time = ktime_to_us(now);
-
- do {
- seq = read_seqcount_begin(&ts->sleeptime_seq);
- if (ts->idle_active && nr_iowait_cpu(cpu) > 0) {
- ktime_t delta = ktime_sub(now, ts->idle_entrytime);
- iowait = ktime_add(ts->iowait_sleeptime, delta);
- } else {
- iowait = ts->iowait_sleeptime;
- }
- } while (read_seqcount_retry(&ts->sleeptime_seq, seq));
-
- return ktime_to_us(iowait);
+ return get_cpu_sleep_time_us(cpu, true, last_update_time);
}
EXPORT_SYMBOL_GPL(get_cpu_iowait_time_us);
--
1.7.5.4
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