From: Arjan van de Ven on
From 166b7526ccfea8b44626b6023ff5b0a8eb869bb3 Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <arjan(a)linux.intel.com>
Date: Sun, 18 Apr 2010 10:33:02 -0700
Subject: [PATCH 2/7] sched: introduce a function to update the idle statistics

Currently, two places update the idle statistics (and more to
come later in this series).

This patch creates a helper function for updating these statistics.

Signed-off-by: Arjan van de Ven <arjan(a)linux.intel.com>
---
kernel/time/tick-sched.c | 29 +++++++++++++++++++----------
1 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 54dc155..ca2211d 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -150,14 +150,25 @@ static void tick_nohz_update_jiffies(ktime_t now)
touch_softlockup_watchdog();
}

-static void tick_nohz_stop_idle(int cpu, ktime_t now)
+/*
+ * Updates the per cpu time idle statistics counters
+ */
+static void update_ts_time_stats(struct tick_sched *ts, ktime_t now)
{
- struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
ktime_t delta;

- delta = ktime_sub(now, ts->idle_entrytime);
ts->idle_lastupdate = now;
- ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
+ if (ts->idle_active) {
+ delta = ktime_sub(now, ts->idle_entrytime);
+ ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
+ }
+}
+
+static void tick_nohz_stop_idle(int cpu, ktime_t now)
+{
+ struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+
+ update_ts_time_stats(ts, now);
ts->idle_active = 0;

sched_clock_idle_wakeup_event(0);
@@ -165,14 +176,12 @@ static void tick_nohz_stop_idle(int cpu, ktime_t now)

static ktime_t tick_nohz_start_idle(struct tick_sched *ts)
{
- ktime_t now, delta;
+ ktime_t now;

now = ktime_get();
- if (ts->idle_active) {
- delta = ktime_sub(now, ts->idle_entrytime);
- ts->idle_lastupdate = now;
- ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
- }
+
+ update_ts_time_stats(ts, now);
+
ts->idle_entrytime = now;
ts->idle_active = 1;
sched_clock_idle_sleep_event();
--
1.6.2.5

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