On Mon, Sep 12, 2016 at 09:47:52AM +0200, Vincent Guittot wrote:
-dequeue task -put task -change the property -enqueue task -set task as current task
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 3e52d08..7a9c9b9 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1105,10 +1105,10 @@ void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) p->sched_class->set_cpus_allowed(p, new_mask);
- if (running)
p->sched_class->set_curr_task(rq);
- if (running)
p->sched_class->set_curr_task(rq);} /*
So one thing that I've wanted to do for a while, but never managed to come up with a sensible way to do is encapsulate this pattern.
The two options I came up with are:
#define FOO(p, stmt) ({ struct rq *rq = task_rq(p); bool queued = task_on_rq_queued(p); bool running = task_current(rq); int queue_flags = DEQUEUE_SAVE; /* also ENQUEUE_RESTORE */
if (queued) dequeue_task(rq, p, queue_flags); if (running) put_prev_task(rq, p);
stmt;
if (queued) enqueue_task(rq, p, queue_flags); if (running) set_curr_task(rq, p); })
and
void foo(struct task_struct *p, void (*func)(struct task_struct *, int *)) { struct rq *rq = task_rq(p); bool queued = task_on_rq_queued(p); bool running = task_current(rq); int queue_flags = DEQUEUE_SAVE; /* also ENQUEUE_RESTORE */
if (queued) dequeue_task(rq, p, queue_flags); if (running) put_prev_task(rq, p);
func(p, &queue_flags);
if (queued) enqueue_task(rq, p, queue_flags); if (running) set_curr_task(rq, p); }
Neither results in particularly pretty code. Although I suppose if I'd have to pick one I'd go for the macro variant.
Opinions? I'm fine with leaving the code as is, just wanted to throw this out there.