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Commit a475c2f4 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Arnd Bergmann
Browse files

[POWERPC] spufs: remove woken threads from the runqueue early 



A single context should only be woken once, and we should not have
more wakeups for a given priority than the number of contexts on
that runqueue position.

Also add some asserts to trap future problems in this area more
easily.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarArnd Bergmann <arnd.bergmann@de.ibm.com>
parent 390c5343

arch/powerpc/platforms/cell/spufs/context.c

+2 −0
Original line number Diff line number Diff line
@@ -52,6 +52,7 @@ struct spu_context *alloc_spu_context(struct spu_gang *gang) 
	ctx->state = SPU_STATE_SAVED;

	ctx->ops = &spu_backing_ops;

	ctx->owner = get_task_mm(current);

	INIT_LIST_HEAD(&ctx->rq);

	if (gang)

		spu_gang_add_ctx(gang, ctx);

	ctx->rt_priority = current->rt_priority;
@@ -76,6 +77,7 @@ void destroy_spu_context(struct kref *kref) 
	spu_fini_csa(&ctx->csa);

	if (ctx->gang)

		spu_gang_remove_ctx(ctx->gang, ctx);

	BUG_ON(!list_empty(&ctx->rq));

	kfree(ctx);

}

arch/powerpc/platforms/cell/spufs/sched.c

+17 −27
Original line number Diff line number Diff line
@@ -245,38 +245,23 @@ static void spu_add_to_rq(struct spu_context *ctx) 
	spin_unlock(&spu_prio->runq_lock);

}



/**

 * spu_del_from_rq - remove a context from the runqueue

 * @ctx:       context to remove

 */

static void spu_del_from_rq(struct spu_context *ctx)

static void __spu_del_from_rq(struct spu_context *ctx, int prio)

{

	spin_lock(&spu_prio->runq_lock);

	if (!list_empty(&ctx->rq))

		list_del_init(&ctx->rq);

	if (list_empty(&spu_prio->runq[ctx->prio]))

	if (list_empty(&spu_prio->runq[prio]))

		clear_bit(ctx->prio, spu_prio->bitmap);

	spin_unlock(&spu_prio->runq_lock);

}



/**

 * spu_grab_context - remove one context from the runqueue

 * @prio:      priority of the context to be removed

 *

 * This function removes one context from the runqueue for priority @prio.

 * If there is more than one context with the given priority the first

 * task on the runqueue will be taken.

 *

 * Returns the spu_context it just removed.

 *

 * Must be called with spu_prio->runq_lock held.

 * spu_del_from_rq - remove a context from the runqueue

 * @ctx:       context to remove

 */

static struct spu_context *spu_grab_context(int prio)

static void spu_del_from_rq(struct spu_context *ctx)

{

	struct list_head *rq = &spu_prio->runq[prio];



	if (list_empty(rq))

		return NULL;

	return list_entry(rq->next, struct spu_context, rq);

	spin_lock(&spu_prio->runq_lock);

	__spu_del_from_rq(ctx, ctx->prio);

	spin_unlock(&spu_prio->runq_lock);

}



static void spu_prio_wait(struct spu_context *ctx)
@@ -309,8 +294,13 @@ static void spu_reschedule(struct spu *spu) 
	spin_lock(&spu_prio->runq_lock);

	best = sched_find_first_bit(spu_prio->bitmap);

	if (best < MAX_PRIO) {

		struct spu_context *ctx = spu_grab_context(best);

		if (ctx)

		struct list_head *rq = &spu_prio->runq[best];

		struct spu_context *ctx;



		BUG_ON(list_empty(rq));



		ctx = list_entry(rq->next, struct spu_context, rq);

		__spu_del_from_rq(ctx, best);

		wake_up(&ctx->stop_wq);

	}

	spin_unlock(&spu_prio->runq_lock);