Merge branch 'for-3.4/core' of git://git.kernel.dk/linux-block

Pull block core bits from Jens Axboe:
 "It's a nice and quiet round this time, since most of the tricky stuff
  has been pushed to 3.5 to give it more time to mature.  After a few
  hectic block IO core changes for 3.3 and 3.2, I'm quite happy with a
  slow round.

  Really minor stuff in here, the only real functional change is making
  the auto-unplug threshold a per-queue entity.  The threshold is set so
  that it's low enough that we don't hold off IO for too long, but still
  big enough to get a nice benefit from the batched insert (and hence
  queue lock cost reduction).  For raid configurations, this currently
  breaks down."

* 'for-3.4/core' of git://git.kernel.dk/linux-block:
  block: make auto block plug flush threshold per-disk based
  Documentation: Add sysfs ABI change for cfq's target latency.
  block: Make cfq_target_latency tunable through sysfs.
  block: use lockdep_assert_held for queue locking
  block: blk_alloc_queue_node(): use caller's GFP flags instead of GFP_KERNEL

Documentation/ABI/testing/sysfs-cfq-target-latency

@@ -0,0 +1,8 @@
+What:		/sys/block/<device>/iosched/target_latency
+Date:		March 2012
+contact:	Tao Ma <boyu.mt@taobao.com>
+Description:
+		The /sys/block/<device>/iosched/target_latency only exists
+		when the user sets cfq to /sys/block/<device>/scheduler.
+		It contains an estimated latency time for the cfq. cfq will
+		use it to calculate the time slice used for every task.

block/blk-core.c

@@ -483,7 +483,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
 	if (!q)
 		return NULL;
 
-	q->id = ida_simple_get(&blk_queue_ida, 0, 0, GFP_KERNEL);
+	q->id = ida_simple_get(&blk_queue_ida, 0, 0, gfp_mask);
 	if (q->id < 0)
 		goto fail_q;
 
@@ -1277,7 +1277,8 @@ static bool attempt_plug_merge(struct request_queue *q, struct bio *bio,
 	list_for_each_entry_reverse(rq, &plug->list, queuelist) {
 		int el_ret;
 
-		(*request_count)++;
+		if (rq->q == q)
+			(*request_count)++;
 
 		if (rq->q != q || !blk_rq_merge_ok(rq, bio))
 			continue;

block/blk-throttle.c

@@ -1218,7 +1218,7 @@ void blk_throtl_drain(struct request_queue *q)
 	struct bio_list bl;
 	struct bio *bio;
 
-	WARN_ON_ONCE(!queue_is_locked(q));
+	queue_lockdep_assert_held(q);
 
 	bio_list_init(&bl);
 

block/cfq-iosched.c

@@ -295,6 +295,7 @@ struct cfq_data {
 	unsigned int cfq_slice_idle;
 	unsigned int cfq_group_idle;
 	unsigned int cfq_latency;
+	unsigned int cfq_target_latency;
 
 	/*
 	 * Fallback dummy cfqq for extreme OOM conditions
@@ -604,7 +605,7 @@ cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg)
 {
 	struct cfq_rb_root *st = &cfqd->grp_service_tree;
 
-	return cfq_target_latency * cfqg->weight / st->total_weight;
+	return cfqd->cfq_target_latency * cfqg->weight / st->total_weight;
 }
 
 static inline unsigned
@@ -2271,7 +2272,8 @@ static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg)
 		 * to have higher weight. A more accurate thing would be to
 		 * calculate system wide asnc/sync ratio.
 		 */
-		tmp = cfq_target_latency * cfqg_busy_async_queues(cfqd, cfqg);
+		tmp = cfqd->cfq_target_latency *
+			cfqg_busy_async_queues(cfqd, cfqg);
 		tmp = tmp/cfqd->busy_queues;
 		slice = min_t(unsigned, slice, tmp);
 
@@ -3737,6 +3739,7 @@ static void *cfq_init_queue(struct request_queue *q)
 	cfqd->cfq_back_penalty = cfq_back_penalty;
 	cfqd->cfq_slice[0] = cfq_slice_async;
 	cfqd->cfq_slice[1] = cfq_slice_sync;
+	cfqd->cfq_target_latency = cfq_target_latency;
 	cfqd->cfq_slice_async_rq = cfq_slice_async_rq;
 	cfqd->cfq_slice_idle = cfq_slice_idle;
 	cfqd->cfq_group_idle = cfq_group_idle;
@@ -3788,6 +3791,7 @@ SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1);
 SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1);
 SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0);
 SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0);
+SHOW_FUNCTION(cfq_target_latency_show, cfqd->cfq_target_latency, 1);
 #undef SHOW_FUNCTION
 
 #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV)			\
@@ -3821,6 +3825,7 @@ STORE_FUNCTION(cfq_slice_async_store, &cfqd->cfq_slice[0], 1, UINT_MAX, 1);
 STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1,
 		UINT_MAX, 0);
 STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0);
+STORE_FUNCTION(cfq_target_latency_store, &cfqd->cfq_target_latency, 1, UINT_MAX, 1);
 #undef STORE_FUNCTION
 
 #define CFQ_ATTR(name) \
@@ -3838,6 +3843,7 @@ static struct elv_fs_entry cfq_attrs[] = {
 	CFQ_ATTR(slice_idle),
 	CFQ_ATTR(group_idle),
 	CFQ_ATTR(low_latency),
+	CFQ_ATTR(target_latency),
 	__ATTR_NULL
 };
 

include/linux/blkdev.h

@@ -426,14 +426,10 @@ struct request_queue {
 				 (1 << QUEUE_FLAG_SAME_COMP)	|	\
 				 (1 << QUEUE_FLAG_ADD_RANDOM))
 
-static inline int queue_is_locked(struct request_queue *q)
+static inline void queue_lockdep_assert_held(struct request_queue *q)
 {
-#ifdef CONFIG_SMP
-	spinlock_t *lock = q->queue_lock;
-	return lock && spin_is_locked(lock);
-#else
-	return 1;
-#endif
+	if (q->queue_lock)
+		lockdep_assert_held(q->queue_lock);
 }
 
 static inline void queue_flag_set_unlocked(unsigned int flag,
@@ -445,7 +441,7 @@ static inline void queue_flag_set_unlocked(unsigned int flag,
 static inline int queue_flag_test_and_clear(unsigned int flag,
 					    struct request_queue *q)
 {
-	WARN_ON_ONCE(!queue_is_locked(q));
+	queue_lockdep_assert_held(q);
 
 	if (test_bit(flag, &q->queue_flags)) {
 		__clear_bit(flag, &q->queue_flags);
@@ -458,7 +454,7 @@ static inline int queue_flag_test_and_clear(unsigned int flag,
 static inline int queue_flag_test_and_set(unsigned int flag,
 					  struct request_queue *q)
 {
-	WARN_ON_ONCE(!queue_is_locked(q));
+	queue_lockdep_assert_held(q);
 
 	if (!test_bit(flag, &q->queue_flags)) {
 		__set_bit(flag, &q->queue_flags);
@@ -470,7 +466,7 @@ static inline int queue_flag_test_and_set(unsigned int flag,
 
 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
 {
-	WARN_ON_ONCE(!queue_is_locked(q));
+	queue_lockdep_assert_held(q);
 	__set_bit(flag, &q->queue_flags);
 }
 
@@ -487,7 +483,7 @@ static inline int queue_in_flight(struct request_queue *q)
 
 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
 {
-	WARN_ON_ONCE(!queue_is_locked(q));
+	queue_lockdep_assert_held(q);
 	__clear_bit(flag, &q->queue_flags);
 }