5 files changed, 27 insertions, 16 deletions

diff --git a/Documentation/ABI/testing/sysfs-cfq-target-latency b/Documentation/ABI/testing/sysfs-cfq-target-latency
new file mode 100644
index 00000000000..df0f7828c5e
--- /dev/null
+++ b/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.
diff --git a/block/blk-core.c b/block/blk-core.c
index 3a78b00edd7..1f61b74867e 100644
--- a/block/blk-core.c
+++ b/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;
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 5eed6a76721..f2ddb94626b 100644
--- a/block/blk-throttle.c
+++ b/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);
 
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 45729525356..3c38536bd52 100644
--- a/block/cfq-iosched.c
+++ b/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 @@ new_workload:
                  * 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
 };
 
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 606cf339bb5..2aa24664a5b 100644
--- a/include/linux/blkdev.h
+++ b/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);
 }