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authorMike Travis <travis@sgi.com>2008-03-26 14:23:49 -0700
committerIngo Molnar <mingo@elte.hu>2008-04-19 19:44:59 +0200
commitcd8ba7cd9be0192348c2836cb6645d9b2cd2bfd2 (patch)
tree3b4138c7b683c2168ac13be41aab74b49a6bcf1c /kernel
parente0982e90cd1ecf59818b137386b7f63debded9cc (diff)
downloadop-kernel-dev-cd8ba7cd9be0192348c2836cb6645d9b2cd2bfd2.zip
op-kernel-dev-cd8ba7cd9be0192348c2836cb6645d9b2cd2bfd2.tar.gz
sched: add new set_cpus_allowed_ptr function
Add a new function that accepts a pointer to the "newly allowed cpus" cpumask argument. int set_cpus_allowed_ptr(struct task_struct *p, const cpumask_t *new_mask) The current set_cpus_allowed() function is modified to use the above but this does not result in an ABI change. And with some compiler optimization help, it may not introduce any additional overhead. Additionally, to enforce the read only nature of the new_mask arg, the "const" property is migrated to sub-functions called by set_cpus_allowed. This silences compiler warnings. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sched.c16
-rw-r--r--kernel/sched_rt.c3
2 files changed, 10 insertions, 9 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 6ab0fcb..521b89b 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5486,7 +5486,7 @@ static inline void sched_init_granularity(void)
* task must not exit() & deallocate itself prematurely. The
* call is not atomic; no spinlocks may be held.
*/
-int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
+int set_cpus_allowed_ptr(struct task_struct *p, const cpumask_t *new_mask)
{
struct migration_req req;
unsigned long flags;
@@ -5494,23 +5494,23 @@ int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
int ret = 0;
rq = task_rq_lock(p, &flags);
- if (!cpus_intersects(new_mask, cpu_online_map)) {
+ if (!cpus_intersects(*new_mask, cpu_online_map)) {
ret = -EINVAL;
goto out;
}
if (p->sched_class->set_cpus_allowed)
- p->sched_class->set_cpus_allowed(p, &new_mask);
+ p->sched_class->set_cpus_allowed(p, new_mask);
else {
- p->cpus_allowed = new_mask;
- p->rt.nr_cpus_allowed = cpus_weight(new_mask);
+ p->cpus_allowed = *new_mask;
+ p->rt.nr_cpus_allowed = cpus_weight(*new_mask);
}
/* Can the task run on the task's current CPU? If so, we're done */
- if (cpu_isset(task_cpu(p), new_mask))
+ if (cpu_isset(task_cpu(p), *new_mask))
goto out;
- if (migrate_task(p, any_online_cpu(new_mask), &req)) {
+ if (migrate_task(p, any_online_cpu(*new_mask), &req)) {
/* Need help from migration thread: drop lock and wait. */
task_rq_unlock(rq, &flags);
wake_up_process(rq->migration_thread);
@@ -5523,7 +5523,7 @@ out:
return ret;
}
-EXPORT_SYMBOL_GPL(set_cpus_allowed);
+EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);
/*
* Move (not current) task off this cpu, onto dest cpu. We're doing
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 6928ded..8ff8245 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1123,7 +1123,8 @@ move_one_task_rt(struct rq *this_rq, int this_cpu, struct rq *busiest,
return 0;
}
-static void set_cpus_allowed_rt(struct task_struct *p, cpumask_t *new_mask)
+static void set_cpus_allowed_rt(struct task_struct *p,
+ const cpumask_t *new_mask)
{
int weight = cpus_weight(*new_mask);
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