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

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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: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
This commit is contained in:
Christoph Hellwig 2007-04-23 21:08:11 +02:00 committed by Arnd Bergmann
parent 390c534304
commit a475c2f435
2 changed files with 19 additions and 27 deletions
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2
arch/powerpc/platforms/cell/spufs/context.c
View File

@ -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);
}

44
arch/powerpc/platforms/cell/spufs/sched.c
View File

@ -245,6 +245,14 @@ static void spu_add_to_rq(struct spu_context *ctx)
spin_unlock(&spu_prio->runq_lock);
}
static void __spu_del_from_rq(struct spu_context *ctx, int prio)
{
if (!list_empty(&ctx->rq))
list_del_init(&ctx->rq);
if (list_empty(&spu_prio->runq[prio]))
clear_bit(ctx->prio, spu_prio->bitmap);
}
/**
* spu_del_from_rq - remove a context from the runqueue
* @ctx: context to remove
@ -252,33 +260,10 @@ static void spu_add_to_rq(struct spu_context *ctx)
static void spu_del_from_rq(struct spu_context *ctx)
{
spin_lock(&spu_prio->runq_lock);
list_del_init(&ctx->rq);
if (list_empty(&spu_prio->runq[ctx->prio]))
clear_bit(ctx->prio, spu_prio->bitmap);
__spu_del_from_rq(ctx, ctx->prio);
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.
*/
static struct spu_context *spu_grab_context(int prio)
{
struct list_head *rq = &spu_prio->runq[prio];
if (list_empty(rq))
return NULL;
return list_entry(rq->next, struct spu_context, rq);
}
static void spu_prio_wait(struct spu_context *ctx)
{
DEFINE_WAIT(wait);
@ -309,9 +294,14 @@ 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)
wake_up(&ctx->stop_wq);
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);
}