[PATCH 5/7] sched: eliminate the ts->idle_lastupdate field

[Arjan van de Ven <arjan@infradead.org>]

>From 526a9f347d5a953f37b67b4b2afb39d7b4d77a92 Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <arjan@linux.intel.com>
Date: Sun, 18 Apr 2010 10:49:30 -0700
Subject: [PATCH 5/7] sched: eliminate the ts->idle_lastupdate field

Now that the only user of ts->idle_lastupdate is update_ts_time_stats(),
the entire field can be eliminated.

In update_ts_time_stats(), idle_lastupdate is first set to "now",
and a few lines later, the only user is an if() statement that
assigns a variable either to "now" or to ts->idle_lastupdate,
which has the value of "now" at that point.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
---
 include/linux/tick.h     |    1 -
 kernel/time/tick-sched.c |    5 +----
 2 files changed, 1 insertions(+), 5 deletions(-)

diff --git a/include/linux/tick.h b/include/linux/tick.h
index d2ae79e..0343eed 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -60,7 +60,6 @@ struct tick_sched {
 	ktime_t				idle_waketime;
 	ktime_t				idle_exittime;
 	ktime_t				idle_sleeptime;
-	ktime_t				idle_lastupdate;
 	ktime_t				sleep_length;
 	unsigned long			last_jiffies;
 	unsigned long			next_jiffies;
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index ac54543..326f5f8 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -158,16 +158,13 @@ update_ts_time_stats(struct tick_sched *ts, ktime_t now, u64 *last_update_time)
 {
 	ktime_t delta;
 
-	ts->idle_lastupdate = now;
 	if (ts->idle_active) {
 		delta = ktime_sub(now, ts->idle_entrytime);
 		ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
 		ts->idle_entrytime = now;
 	}
 
-	if (ts->idle_active && last_update_time)
-		*last_update_time = ktime_to_us(ts->idle_lastupdate);
-	else
+	if (last_update_time)
 		*last_update_time = ktime_to_us(now);
 
 }
-- 
1.6.2.5