From: Nick Piggin <nickpiggin@yahoo.com.au>
Add some likely/unliklies, a comment, and a for_each_cpu =>
for_each_cpu_online.
Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/kernel/sched.c | 9 +++++----
1 files changed, 5 insertions(+), 4 deletions(-)
diff -puN kernel/sched.c~sched-misc-changes kernel/sched.c
--- 25/kernel/sched.c~sched-misc-changes 2004-06-25 02:50:07.372452384 -0700
+++ 25-akpm/kernel/sched.c 2004-06-25 02:50:07.378451472 -0700
@@ -943,7 +943,7 @@ void fastcall sched_fork(task_t *p, unsi
p->first_time_slice = 1;
current->time_slice >>= 1;
p->timestamp = sched_clock();
- if (!current->time_slice) {
+ if (unlikely(!current->time_slice)) {
/*
* This case is rare, it happens when the parent has only
* a single jiffy left from its timeslice. Taking the
@@ -1053,6 +1053,7 @@ void fastcall sched_exit(task_t * p)
local_irq_save(flags);
if (p->first_time_slice) {
+ /* FIXME: updates to ->parent are racy */
p->parent->time_slice += p->time_slice;
if (unlikely(p->parent->time_slice > MAX_TIMESLICE))
p->parent->time_slice = MAX_TIMESLICE;
@@ -1162,7 +1163,7 @@ unsigned long nr_running(void)
{
unsigned long i, sum = 0;
- for_each_cpu(i)
+ for_each_online_cpu(i)
sum += cpu_rq(i)->nr_running;
return sum;
@@ -2275,7 +2276,7 @@ need_resched:
goto switch_tasks;
}
- if (!rt_task(next) && next->activated > 0) {
+ if (likely(!rt_task(next)) && next->activated > 0) {
unsigned long long delta = now - next->timestamp;
if (next->activated == 1)
@@ -2316,7 +2317,7 @@ switch_tasks:
reacquire_kernel_lock(current);
preempt_enable_no_resched();
- if (test_thread_flag(TIF_NEED_RESCHED))
+ if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
goto need_resched;
}
_