[PATCH 17/22] sched: Remove rq argument from ttwu_stat()

Peter Zijlstra
2011-03-02T17:46:24Z

[-- Attachment #1: sched-ttwu_stat-rq.patch --]
[-- Type: text/plain, Size: 1568 bytes --]

In order to call ttwu_stat() without holding rq->lock we must remove
its rq argument. Since we need to change rq stats, account to the
local rq instead of the task rq, this is safe since we have IRQs
disabled.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
---
kernel/sched.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

Index: linux-2.6/kernel/sched.c
===================================================================
--- linux-2.6.orig/kernel/sched.c
+++ linux-2.6/kernel/sched.c
@@ -2367,10 +2367,11 @@ static void update_avg(u64 *avg, u64 sam
#endif

static void
-ttwu_stat(struct rq *rq, struct task_struct *p, int cpu, int wake_flags)
+ttwu_stat(struct task_struct *p, int cpu, int wake_flags)
{
#ifdef CONFIG_SCHEDSTATS
int this_cpu = smp_processor_id();
+ struct rq *rq = this_rq();

schedstat_inc(rq, ttwu_count);
schedstat_inc(p, se.statistics.nr_wakeups);
@@ -2491,9 +2492,10 @@ try_to_wake_up(struct task_struct *p, un
activate_task(rq, p, ENQUEUE_WAKEUP | ENQUEUE_WAKING);
out_running:
ttwu_post_activation(p, rq, wake_flags);
- ttwu_stat(rq, p, cpu, wake_flags);
success = 1;
__task_rq_unlock(rq);
+
+ ttwu_stat(p, cpu, wake_flags);
out:
raw_spin_unlock_irqrestore(&p->pi_lock, flags);
put_cpu();
@@ -2527,7 +2529,7 @@ static void try_to_wake_up_local(struct
activate_task(rq, p, ENQUEUE_WAKEUP);

ttwu_post_activation(p, rq, 0);
- ttwu_stat(rq, p, smp_processor_id(), 0);
+ ttwu_stat(p, smp_processor_id(), 0);
out:
raw_spin_unlock(&p->pi_lock);
}