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authorLinus Torvalds <torvalds@linux-foundation.org>2010-07-02 09:52:58 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-07-02 09:52:58 -0700
commit123f94f22e3d283dfe68742b269c245b0501ad82 (patch)
tree1d40043b0909f309cf77204ea87be9e61f143e79
parent4b78c119f0ba715b4e29b190bf4d7bce810ea0d6 (diff)
parent8c215bd3890c347dfb6a2db4779755f8b9c298a9 (diff)
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Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Cure nr_iowait_cpu() users init: Fix comment init, sched: Fix race between init and kthreadd
-rw-r--r--drivers/cpuidle/governors/menu.c4
-rw-r--r--include/linux/sched.h2
-rw-r--r--init/main.c12
-rw-r--r--kernel/sched.c4
-rw-r--r--kernel/time/tick-sched.c16
5 files changed, 25 insertions, 13 deletions
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index 52ff8aa63f8..1b128702d30 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -143,7 +143,7 @@ static inline int which_bucket(unsigned int duration)
* This allows us to calculate
* E(duration)|iowait
*/
- if (nr_iowait_cpu())
+ if (nr_iowait_cpu(smp_processor_id()))
bucket = BUCKETS/2;
if (duration < 10)
@@ -175,7 +175,7 @@ static inline int performance_multiplier(void)
mult += 2 * get_loadavg();
/* for IO wait tasks (per cpu!) we add 5x each */
- mult += 10 * nr_iowait_cpu();
+ mult += 10 * nr_iowait_cpu(smp_processor_id());
return mult;
}
diff --git a/include/linux/sched.h b/include/linux/sched.h
index f118809c953..747fcaedddb 100644
--- a/include/linux/sched.h
+++ b/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 --git a/init/main.c b/init/main.c
index ac2e4a5f59e..a42fdf4aeba 100644
--- a/init/main.c
+++ b/init/main.c
@@ -424,18 +424,26 @@ static void __init setup_command_line(char *command_line)
* gcc-3.4 accidentally inlines this function, so use noinline.
*/
+static __initdata DECLARE_COMPLETION(kthreadd_done);
+
static noinline void __init_refok rest_init(void)
__releases(kernel_lock)
{
int pid;
rcu_scheduler_starting();
+ /*
+ * We need to spawn init first so that it obtains pid 1, however
+ * the init task will end up wanting to create kthreads, which, if
+ * we schedule it before we create kthreadd, will OOPS.
+ */
kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
numa_default_policy();
pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
rcu_read_lock();
kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
rcu_read_unlock();
+ complete(&kthreadd_done);
unlock_kernel();
/*
@@ -857,6 +865,10 @@ static noinline int init_post(void)
static int __init kernel_init(void * unused)
{
+ /*
+ * Wait until kthreadd is all set-up.
+ */
+ wait_for_completion(&kthreadd_done);
lock_kernel();
/*
diff --git a/kernel/sched.c b/kernel/sched.c
index cb816e36cc8..f52a8801b7a 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2873,9 +2873,9 @@ 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 --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 783fbadf220..813993b5fb6 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -154,14 +154,14 @@ static void tick_nohz_update_jiffies(ktime_t now)
* Updates the per cpu time idle statistics counters
*/
static void
-update_ts_time_stats(struct tick_sched *ts, ktime_t now, u64 *last_update_time)
+update_ts_time_stats(int cpu, struct tick_sched *ts, ktime_t now, u64 *last_update_time)
{
ktime_t delta;
if (ts->idle_active) {
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);
ts->idle_entrytime = now;
}
@@ -175,19 +175,19 @@ 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, NULL);
+ update_ts_time_stats(cpu, ts, now, NULL);
ts->idle_active = 0;
sched_clock_idle_wakeup_event(0);
}
-static ktime_t tick_nohz_start_idle(struct tick_sched *ts)
+static ktime_t tick_nohz_start_idle(int cpu, struct tick_sched *ts)
{
ktime_t now;
now = ktime_get();
- update_ts_time_stats(ts, now, NULL);
+ update_ts_time_stats(cpu, ts, now, NULL);
ts->idle_entrytime = now;
ts->idle_active = 1;
@@ -216,7 +216,7 @@ u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time)
if (!tick_nohz_enabled)
return -1;
- update_ts_time_stats(ts, ktime_get(), last_update_time);
+ update_ts_time_stats(cpu, ts, ktime_get(), last_update_time);
return ktime_to_us(ts->idle_sleeptime);
}
@@ -242,7 +242,7 @@ u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time)
if (!tick_nohz_enabled)
return -1;
- update_ts_time_stats(ts, ktime_get(), last_update_time);
+ update_ts_time_stats(cpu, ts, ktime_get(), last_update_time);
return ktime_to_us(ts->iowait_sleeptime);
}
@@ -284,7 +284,7 @@ void tick_nohz_stop_sched_tick(int inidle)
*/
ts->inidle = 1;
- now = tick_nohz_start_idle(ts);
+ now = tick_nohz_start_idle(cpu, ts);
/*
* If this cpu is offline and it is the one which updates