From: Nick Piggin <nickpiggin@yahoo.com.au>
Minor cleanups from Ingo's patch including task_hot (do it right in
try_to_wake_up too).
---
25-akpm/include/linux/sched.h | 6 ++---
25-akpm/kernel/sched.c | 47 ++++++++++++++++--------------------------
2 files changed, 22 insertions(+), 31 deletions(-)
diff -puN include/linux/sched.h~sched-minor-cleanups include/linux/sched.h
--- 25/include/linux/sched.h~sched-minor-cleanups 2004-04-27 20:37:35.189590240 -0700
+++ 25-akpm/include/linux/sched.h 2004-04-27 20:37:35.195589328 -0700
@@ -602,9 +602,9 @@ struct sched_domain {
.cache_nice_tries = 0, \
.per_cpu_gain = 15, \
.flags = SD_BALANCE_NEWIDLE \
- | SD_WAKE_AFFINE \
- | SD_WAKE_IDLE \
- | SD_SHARE_CPUPOWER, \
+ | SD_WAKE_AFFINE \
+ | SD_WAKE_IDLE \
+ | SD_SHARE_CPUPOWER, \
.last_balance = jiffies, \
.balance_interval = 1, \
.nr_balance_failed = 0, \
diff -puN kernel/sched.c~sched-minor-cleanups kernel/sched.c
--- 25/kernel/sched.c~sched-minor-cleanups 2004-04-27 20:37:35.191589936 -0700
+++ 25-akpm/kernel/sched.c 2004-04-27 20:37:35.198588872 -0700
@@ -187,6 +187,8 @@ static inline unsigned int task_timeslic
return BASE_TIMESLICE(p);
}
+#define task_hot(p, now, sd) ((now) - (p)->timestamp < (sd)->cache_hot_time)
+
/*
* These are the runqueue data structures:
*/
@@ -704,13 +706,11 @@ static inline int wake_idle(int cpu, tas
*/
static int try_to_wake_up(task_t * p, unsigned int state, int sync)
{
+ int cpu, this_cpu, success = 0;
unsigned long flags;
- int success = 0;
long old_state;
runqueue_t *rq;
- int cpu, this_cpu;
#ifdef CONFIG_SMP
- unsigned long long now;
unsigned long load, this_load;
struct sched_domain *sd;
int new_cpu;
@@ -753,8 +753,6 @@ static int try_to_wake_up(task_t * p, un
if (load > this_load + SCHED_LOAD_SCALE*2)
goto out_set_cpu;
- now = sched_clock();
-
/*
* Migrate the task to the waking domain.
* Do not violate hard affinity.
@@ -762,7 +760,7 @@ static int try_to_wake_up(task_t * p, un
for_each_domain(this_cpu, sd) {
if (!(sd->flags & SD_WAKE_AFFINE))
break;
- if (rq->timestamp_last_tick - p->timestamp < sd->cache_hot_time)
+ if (task_hot(p, rq->timestamp_last_tick, sd))
break;
if (cpu_isset(cpu, sd->span))
@@ -774,22 +772,18 @@ out_set_cpu:
new_cpu = wake_idle(new_cpu, p);
if (new_cpu != cpu && cpu_isset(new_cpu, p->cpus_allowed)) {
set_task_cpu(p, new_cpu);
- goto repeat_lock_task;
- }
- goto out_activate;
-
-repeat_lock_task:
- task_rq_unlock(rq, &flags);
- rq = task_rq_lock(p, &flags);
- old_state = p->state;
- if (!(old_state & state))
- goto out;
-
- if (p->array)
- goto out_running;
+ task_rq_unlock(rq, &flags);
+ /* might preempt at this point */
+ rq = task_rq_lock(p, &flags);
+ old_state = p->state;
+ if (!(old_state & state))
+ goto out;
+ if (p->array)
+ goto out_running;
- this_cpu = smp_processor_id();
- cpu = task_cpu(p);
+ this_cpu = smp_processor_id();
+ cpu = task_cpu(p);
+ }
out_activate:
#endif /* CONFIG_SMP */
@@ -1301,7 +1295,7 @@ int can_migrate_task(task_t *p, runqueue
/* Aggressive migration if we've failed balancing */
if (idle == NEWLY_IDLE ||
sd->nr_balance_failed < sd->cache_nice_tries) {
- if (rq->timestamp_last_tick - p->timestamp < sd->cache_hot_time)
+ if (task_hot(p, rq->timestamp_last_tick, sd))
return 0;
}
@@ -1319,10 +1313,9 @@ static int move_tasks(runqueue_t *this_r
unsigned long max_nr_move, struct sched_domain *sd,
enum idle_type idle)
{
- int idx;
- int pulled = 0;
prio_array_t *array, *dst_array;
struct list_head *head, *curr;
+ int idx, pulled = 0;
task_t *tmp;
if (max_nr_move <= 0 || busiest->nr_running <= 1)
@@ -1411,10 +1404,8 @@ find_busiest_group(struct sched_domain *
/* Tally up the load of all CPUs in the group */
avg_load = 0;
cpus_and(tmp, group->cpumask, cpu_online_map);
- if (unlikely(cpus_empty(tmp))) {
- WARN_ON(1);
- return NULL;
- }
+ if (unlikely(cpus_empty(tmp)))
+ goto nextgroup;
for_each_cpu_mask(i, tmp) {
/* Bias balancing toward cpus of our domain */
_