From 64d01dc9e1927e6535627d73f2336c75d1dd3fe2 Mon Sep 17 00:00:00 2001 From: Cheng Renquan Date: Wed, 3 Dec 2008 12:41:39 +0100 Subject: block: use cancel_work_sync() instead of kblockd_flush_work() After many improvements on kblockd_flush_work, it is now identical to cancel_work_sync, so a direct call to cancel_work_sync is suggested. The only difference is that cancel_work_sync is a GPL symbol, so no non-GPL modules anymore. Signed-off-by: Cheng Renquan Cc: Jens Axboe Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'block/cfq-iosched.c') diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 6a062eebbd15..a2bfec7d6b36 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -2160,7 +2160,7 @@ out_cont: static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) { del_timer_sync(&cfqd->idle_slice_timer); - kblockd_flush_work(&cfqd->unplug_work); + cancel_work_sync(&cfqd->unplug_work); } static void cfq_put_async_queues(struct cfq_data *cfqd) -- cgit v1.2.2 From b374d18a4bfce705e4a99ae9f501b53e86ecb283 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 31 Oct 2008 10:05:07 +0100 Subject: block: get rid of elevator_t typedef Just use struct elevator_queue everywhere instead. Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'block/cfq-iosched.c') diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index a2bfec7d6b36..adaf93a9d19d 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -2178,7 +2178,7 @@ static void cfq_put_async_queues(struct cfq_data *cfqd) cfq_put_queue(cfqd->async_idle_cfqq); } -static void cfq_exit_queue(elevator_t *e) +static void cfq_exit_queue(struct elevator_queue *e) { struct cfq_data *cfqd = e->elevator_data; struct request_queue *q = cfqd->queue; @@ -2288,7 +2288,7 @@ cfq_var_store(unsigned int *var, const char *page, size_t count) } #define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ -static ssize_t __FUNC(elevator_t *e, char *page) \ +static ssize_t __FUNC(struct elevator_queue *e, char *page) \ { \ struct cfq_data *cfqd = e->elevator_data; \ unsigned int __data = __VAR; \ @@ -2308,7 +2308,7 @@ SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0); #undef SHOW_FUNCTION #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ -static ssize_t __FUNC(elevator_t *e, const char *page, size_t count) \ +static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \ { \ struct cfq_data *cfqd = e->elevator_data; \ unsigned int __data; \ -- cgit v1.2.2 From 30e0dc28bff9dc456cdfc2aae4aca78b8b1a1cec Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 20 Oct 2008 15:44:28 +0200 Subject: cfq-iosched: remove limit of dispatch depth of max 4 times quantum This basically limits the hardware queue depth to 4*quantum at any point in time, which is 16 with the default settings. As CFQ uses other means to shrink the hardware queue when necessary in the first place, there's really no need for this extra heuristic. Additionally, it ends up hurting performance in some cases. Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'block/cfq-iosched.c') diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index adaf93a9d19d..ee8a90c7c46c 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -1136,12 +1136,8 @@ static int cfq_dispatch_requests(struct request_queue *q, int force) if (cfq_class_idle(cfqq)) max_dispatch = 1; - if (cfqq->dispatched >= max_dispatch) { - if (cfqd->busy_queues > 1) - break; - if (cfqq->dispatched >= 4 * max_dispatch) - break; - } + if (cfqq->dispatched >= max_dispatch && cfqd->busy_queues > 1) + break; if (cfqd->sync_flight && !cfq_cfqq_sync(cfqq)) break; -- cgit v1.2.2 From 62c1fe9d9f0a676fce89185b1513f0e5f473c72c Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 15 Dec 2008 21:19:25 +0100 Subject: cfq-iosched: fix race between exiting queue and exiting task Original patch from Nikanth Karthikesan When a queue exits the queue lock is taken and cfq_exit_queue() would free all the cic's associated with the queue. But when a task exits, cfq_exit_io_context() gets cic one by one and then locks the associated queue to call __cfq_exit_single_io_context. It looks like between getting a cic from the ioc and locking the queue, the queue might have exited on another cpu. Fix this by rechecking the cfq_io_context queue key inside the queue lock again, and not calling into __cfq_exit_single_io_context() if somebody beat us to it. Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'block/cfq-iosched.c') diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index ee8a90c7c46c..e8525fa72823 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -1314,7 +1314,15 @@ static void cfq_exit_single_io_context(struct io_context *ioc, unsigned long flags; spin_lock_irqsave(q->queue_lock, flags); - __cfq_exit_single_io_context(cfqd, cic); + + /* + * Ensure we get a fresh copy of the ->key to prevent + * race between exiting task and queue + */ + smp_read_barrier_depends(); + if (cic->key) + __cfq_exit_single_io_context(cfqd, cic); + spin_unlock_irqrestore(q->queue_lock, flags); } } -- cgit v1.2.2