2.6.35-rc2-git2: Reported regressions from 2.6.34

Commit Message

Andrew Morton June 16, 2010, 8:42 p.m. UTC

None

Patch

diff -puN drivers/cpuidle/governors/menu.c~cpuidle-avoid-using-smp_processor_id-in-preemptible-code-nr_iowait_cpu drivers/cpuidle/governors/menu.c
--- a/drivers/cpuidle/governors/menu.c~cpuidle-avoid-using-smp_processor_id-in-preemptible-code-nr_iowait_cpu
+++ a/drivers/cpuidle/governors/menu.c
@@ -137,15 +137,18 @@  static inline int which_bucket(unsigned 
 {
 	int bucket = 0;
 
+	int cpu = get_cpu();
 	/*
 	 * We keep two groups of stats; one with no
 	 * IO pending, one without.
 	 * This allows us to calculate
 	 * E(duration)|iowait
 	 */
-	if (nr_iowait_cpu())
+	if (nr_iowait_cpu(cpu))
 		bucket = BUCKETS/2;
 
+	put_cpu();
+
 	if (duration < 10)
 		return bucket;
 	if (duration < 100)
@@ -169,13 +172,16 @@  static inline int which_bucket(unsigned 
 static inline int performance_multiplier(void)
 {
 	int mult = 1;
+	int cpu = get_cpu();
 
 	/* for higher loadavg, we are more reluctant */
 
 	mult += 2 * get_loadavg();
 
 	/* for IO wait tasks (per cpu!) we add 5x each */
-	mult += 10 * nr_iowait_cpu();
+	mult += 10 * nr_iowait_cpu(cpu);
+
+	put_cpu();
 
 	return mult;
 }
diff -puN include/linux/sched.h~cpuidle-avoid-using-smp_processor_id-in-preemptible-code-nr_iowait_cpu include/linux/sched.h
--- a/include/linux/sched.h~cpuidle-avoid-using-smp_processor_id-in-preemptible-code-nr_iowait_cpu
+++ a/include/linux/sched.h
@@ -139,7 +139,7 @@  extern int nr_processes(void);
 extern unsigned long nr_running(void);
 extern unsigned long nr_uninterruptible(void);
 extern unsigned long nr_iowait(void);
-extern unsigned long nr_iowait_cpu(void);
+extern unsigned long nr_iowait_cpu(int cpu);
 extern unsigned long this_cpu_load(void);
 
 
diff -puN kernel/sched.c~cpuidle-avoid-using-smp_processor_id-in-preemptible-code-nr_iowait_cpu kernel/sched.c
--- a/kernel/sched.c~cpuidle-avoid-using-smp_processor_id-in-preemptible-code-nr_iowait_cpu
+++ a/kernel/sched.c
@@ -2864,9 +2864,9 @@  unsigned long nr_iowait(void)
 	return sum;
 }
 
-unsigned long nr_iowait_cpu(void)
+unsigned long nr_iowait_cpu(int cpu)
 {
-	struct rq *this = this_rq();
+	struct rq *this = cpu_rq(cpu);
 	return atomic_read(&this->nr_iowait);
 }
 
diff -puN kernel/time/tick-sched.c~cpuidle-avoid-using-smp_processor_id-in-preemptible-code-nr_iowait_cpu kernel/time/tick-sched.c
--- a/kernel/time/tick-sched.c~cpuidle-avoid-using-smp_processor_id-in-preemptible-code-nr_iowait_cpu
+++ a/kernel/time/tick-sched.c
@@ -159,10 +159,12 @@  update_ts_time_stats(struct tick_sched *
 	ktime_t delta;
 
 	if (ts->idle_active) {
+		int cpu = get_cpu();
 		delta = ktime_sub(now, ts->idle_entrytime);
 		ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
-		if (nr_iowait_cpu() > 0)
+		if (nr_iowait_cpu(cpu) > 0)
 			ts->iowait_sleeptime = ktime_add(ts->iowait_sleeptime, delta);
+		put_cpu();
 		ts->idle_entrytime = now;
 	}