From d9ff41879364cfca7c15abc20ae398e35de3f883 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 18 Mar 2006 13:51:22 -0500 Subject: [PATCH] [PATCH] make cfq_exit_queue() prune the cfq_io_context for that queue Signed-off-by: Al Viro --- block/cfq-iosched.c | 59 +++++++++++++++++++++++++++++++++++++++++- include/linux/blkdev.h | 2 ++ 2 files changed, 60 insertions(+), 1 deletion(-) diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 3bacf4bb7dd2..3fc6e505e9c8 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -177,6 +177,8 @@ struct cfq_data { unsigned int cfq_slice_async_rq; unsigned int cfq_slice_idle; unsigned int cfq_max_depth; + + struct list_head cic_list; }; /* @@ -1215,7 +1217,12 @@ static void cfq_free_io_context(struct cfq_io_context *cic) static void cfq_exit_single_io_context(struct cfq_io_context *cic) { struct cfq_data *cfqd = cic->key; - request_queue_t *q = cfqd->queue; + request_queue_t *q; + + if (!cfqd) + return; + + q = cfqd->queue; WARN_ON(!irqs_disabled()); @@ -1236,6 +1243,7 @@ static void cfq_exit_single_io_context(struct cfq_io_context *cic) } cic->key = NULL; + list_del_init(&cic->queue_list); spin_unlock(q->queue_lock); } @@ -1254,12 +1262,14 @@ static void cfq_exit_io_context(struct cfq_io_context *cic) /* * put the reference this task is holding to the various queues */ + read_lock(&cfq_exit_lock); list_for_each(entry, &cic->list) { __cic = list_entry(entry, struct cfq_io_context, list); cfq_exit_single_io_context(__cic); } cfq_exit_single_io_context(cic); + read_unlock(&cfq_exit_lock); local_irq_restore(flags); } @@ -1279,6 +1289,7 @@ cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) cic->ttime_mean = 0; cic->dtor = cfq_free_io_context; cic->exit = cfq_exit_io_context; + INIT_LIST_HEAD(&cic->queue_list); } return cic; @@ -1446,6 +1457,7 @@ cfq_get_io_context(struct cfq_data *cfqd, pid_t pid, gfp_t gfp_mask) if (!ioc) return NULL; +restart: if ((cic = ioc->cic) == NULL) { cic = cfq_alloc_io_context(cfqd, gfp_mask); @@ -1461,6 +1473,7 @@ cfq_get_io_context(struct cfq_data *cfqd, pid_t pid, gfp_t gfp_mask) read_lock(&cfq_exit_lock); ioc->set_ioprio = cfq_ioc_set_ioprio; ioc->cic = cic; + list_add(&cic->queue_list, &cfqd->cic_list); read_unlock(&cfq_exit_lock); } else { struct cfq_io_context *__cic; @@ -1471,6 +1484,19 @@ cfq_get_io_context(struct cfq_data *cfqd, pid_t pid, gfp_t gfp_mask) if (cic->key == cfqd) goto out; + if (unlikely(!cic->key)) { + read_lock(&cfq_exit_lock); + if (list_empty(&cic->list)) + ioc->cic = NULL; + else + ioc->cic = list_entry(cic->list.next, + struct cfq_io_context, + list); + read_unlock(&cfq_exit_lock); + kmem_cache_free(cfq_ioc_pool, cic); + goto restart; + } + /* * cic exists, check if we already are there. linear search * should be ok here, the list will usually not be more than @@ -1485,6 +1511,13 @@ cfq_get_io_context(struct cfq_data *cfqd, pid_t pid, gfp_t gfp_mask) cic = __cic; goto out; } + if (unlikely(!__cic->key)) { + read_lock(&cfq_exit_lock); + list_del(&__cic->list); + read_unlock(&cfq_exit_lock); + kmem_cache_free(cfq_ioc_pool, __cic); + goto restart; + } } /* @@ -1499,6 +1532,7 @@ cfq_get_io_context(struct cfq_data *cfqd, pid_t pid, gfp_t gfp_mask) __cic->key = cfqd; read_lock(&cfq_exit_lock); list_add(&__cic->list, &cic->list); + list_add(&__cic->queue_list, &cfqd->cic_list); read_unlock(&cfq_exit_lock); cic = __cic; } @@ -2104,8 +2138,30 @@ static void cfq_put_cfqd(struct cfq_data *cfqd) static void cfq_exit_queue(elevator_t *e) { struct cfq_data *cfqd = e->elevator_data; + request_queue_t *q = cfqd->queue; cfq_shutdown_timer_wq(cfqd); + write_lock(&cfq_exit_lock); + spin_lock_irq(q->queue_lock); + if (cfqd->active_queue) + __cfq_slice_expired(cfqd, cfqd->active_queue, 0); + while(!list_empty(&cfqd->cic_list)) { + struct cfq_io_context *cic = list_entry(cfqd->cic_list.next, + struct cfq_io_context, + queue_list); + if (cic->cfqq[ASYNC]) { + cfq_put_queue(cic->cfqq[ASYNC]); + cic->cfqq[ASYNC] = NULL; + } + if (cic->cfqq[SYNC]) { + cfq_put_queue(cic->cfqq[SYNC]); + cic->cfqq[SYNC] = NULL; + } + cic->key = NULL; + list_del_init(&cic->queue_list); + } + spin_unlock_irq(q->queue_lock); + write_unlock(&cfq_exit_lock); cfq_put_cfqd(cfqd); } @@ -2127,6 +2183,7 @@ static int cfq_init_queue(request_queue_t *q, elevator_t *e) INIT_LIST_HEAD(&cfqd->cur_rr); INIT_LIST_HEAD(&cfqd->idle_rr); INIT_LIST_HEAD(&cfqd->empty_list); + INIT_LIST_HEAD(&cfqd->cic_list); cfqd->crq_hash = kmalloc(sizeof(struct hlist_head) * CFQ_MHASH_ENTRIES, GFP_KERNEL); if (!cfqd->crq_hash) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index e19cb631084e..80518f703538 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -69,6 +69,8 @@ struct cfq_io_context { unsigned long ttime_samples; unsigned long ttime_mean; + struct list_head queue_list; + void (*dtor)(struct cfq_io_context *); void (*exit)(struct cfq_io_context *); };