From a475c2f43520cb095452201da57395000cfeb94c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 23 Apr 2007 21:08:11 +0200 Subject: [PATCH] [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: Christoph Hellwig Signed-off-by: Arnd Bergmann --- arch/powerpc/platforms/cell/spufs/context.c | 2 ++ arch/powerpc/platforms/cell/spufs/sched.c | 44 +++++++++++------------------ 2 files changed, 19 insertions(+), 27 deletions(-) diff --git a/arch/powerpc/platforms/cell/spufs/context.c b/arch/powerpc/platforms/cell/spufs/context.c index b3954ab..065147f 100644 --- a/arch/powerpc/platforms/cell/spufs/context.c +++ b/arch/powerpc/platforms/cell/spufs/context.c @@ -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); } diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c index 1582d76..876828c 100644 --- a/arch/powerpc/platforms/cell/spufs/sched.c +++ b/arch/powerpc/platforms/cell/spufs/sched.c @@ -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); } -- 2.7.4