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-rw-r--r--block/cfq-iosched.c67
1 files changed, 51 insertions, 16 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 1d9c3c70a9a0..07b706243772 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -43,8 +43,8 @@ static int cfq_slice_idle = HZ / 125;
#define RQ_CIC(rq) ((struct cfq_io_context*)(rq)->elevator_private)
#define RQ_CFQQ(rq) ((rq)->elevator_private2)
-static kmem_cache_t *cfq_pool;
-static kmem_cache_t *cfq_ioc_pool;
+static struct kmem_cache *cfq_pool;
+static struct kmem_cache *cfq_ioc_pool;
static DEFINE_PER_CPU(unsigned long, ioc_count);
static struct completion *ioc_gone;
@@ -219,9 +219,12 @@ static int cfq_queue_empty(request_queue_t *q)
return !cfqd->busy_queues;
}
-static inline pid_t cfq_queue_pid(struct task_struct *task, int rw)
+static inline pid_t cfq_queue_pid(struct task_struct *task, int rw, int is_sync)
{
- if (rw == READ || rw == WRITE_SYNC)
+ /*
+ * Use the per-process queue, for read requests and syncronous writes
+ */
+ if (!(rw & REQ_RW) || is_sync)
return task->pid;
return CFQ_KEY_ASYNC;
@@ -473,7 +476,7 @@ static struct request *
cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio)
{
struct task_struct *tsk = current;
- pid_t key = cfq_queue_pid(tsk, bio_data_dir(bio));
+ pid_t key = cfq_queue_pid(tsk, bio_data_dir(bio), bio_sync(bio));
struct cfq_queue *cfqq;
cfqq = cfq_find_cfq_hash(cfqd, key, tsk->ioprio);
@@ -565,6 +568,33 @@ cfq_merged_requests(request_queue_t *q, struct request *rq,
cfq_remove_request(next);
}
+static int cfq_allow_merge(request_queue_t *q, struct request *rq,
+ struct bio *bio)
+{
+ struct cfq_data *cfqd = q->elevator->elevator_data;
+ const int rw = bio_data_dir(bio);
+ struct cfq_queue *cfqq;
+ pid_t key;
+
+ /*
+ * Disallow merge of a sync bio into an async request.
+ */
+ if ((bio_data_dir(bio) == READ || bio_sync(bio)) && !rq_is_sync(rq))
+ return 0;
+
+ /*
+ * Lookup the cfqq that this bio will be queued with. Allow
+ * merge only if rq is queued there.
+ */
+ key = cfq_queue_pid(current, rw, bio_sync(bio));
+ cfqq = cfq_find_cfq_hash(cfqd, key, current->ioprio);
+
+ if (cfqq == RQ_CFQQ(rq))
+ return 1;
+
+ return 0;
+}
+
static inline void
__cfq_set_active_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
@@ -1464,8 +1494,7 @@ cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_io_context *cic)
}
static void
-cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_io_context *cic,
- struct request *rq)
+cfq_update_io_seektime(struct cfq_io_context *cic, struct request *rq)
{
sector_t sdist;
u64 total;
@@ -1617,7 +1646,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
}
cfq_update_io_thinktime(cfqd, cic);
- cfq_update_io_seektime(cfqd, cic, rq);
+ cfq_update_io_seektime(cic, rq);
cfq_update_idle_window(cfqd, cfqq, cic);
cic->last_queue = jiffies;
@@ -1749,6 +1778,9 @@ static int cfq_may_queue(request_queue_t *q, int rw)
struct cfq_data *cfqd = q->elevator->elevator_data;
struct task_struct *tsk = current;
struct cfq_queue *cfqq;
+ unsigned int key;
+
+ key = cfq_queue_pid(tsk, rw, rw & REQ_RW_SYNC);
/*
* don't force setup of a queue from here, as a call to may_queue
@@ -1756,7 +1788,7 @@ static int cfq_may_queue(request_queue_t *q, int rw)
* so just lookup a possibly existing queue, or return 'may queue'
* if that fails
*/
- cfqq = cfq_find_cfq_hash(cfqd, cfq_queue_pid(tsk, rw), tsk->ioprio);
+ cfqq = cfq_find_cfq_hash(cfqd, key, tsk->ioprio);
if (cfqq) {
cfq_init_prio_data(cfqq);
cfq_prio_boost(cfqq);
@@ -1770,7 +1802,7 @@ static int cfq_may_queue(request_queue_t *q, int rw)
/*
* queue lock held here
*/
-static void cfq_put_request(request_queue_t *q, struct request *rq)
+static void cfq_put_request(struct request *rq)
{
struct cfq_queue *cfqq = RQ_CFQQ(rq);
@@ -1799,10 +1831,10 @@ cfq_set_request(request_queue_t *q, struct request *rq, gfp_t gfp_mask)
struct task_struct *tsk = current;
struct cfq_io_context *cic;
const int rw = rq_data_dir(rq);
- pid_t key = cfq_queue_pid(tsk, rw);
+ const int is_sync = rq_is_sync(rq);
+ pid_t key = cfq_queue_pid(tsk, rw, is_sync);
struct cfq_queue *cfqq;
unsigned long flags;
- int is_sync = key != CFQ_KEY_ASYNC;
might_sleep_if(gfp_mask & __GFP_WAIT);
@@ -1841,9 +1873,11 @@ queue_fail:
return 1;
}
-static void cfq_kick_queue(void *data)
+static void cfq_kick_queue(struct work_struct *work)
{
- request_queue_t *q = data;
+ struct cfq_data *cfqd =
+ container_of(work, struct cfq_data, unplug_work);
+ request_queue_t *q = cfqd->queue;
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
@@ -1951,7 +1985,7 @@ static void cfq_exit_queue(elevator_t *e)
kfree(cfqd);
}
-static void *cfq_init_queue(request_queue_t *q, elevator_t *e)
+static void *cfq_init_queue(request_queue_t *q)
{
struct cfq_data *cfqd;
int i;
@@ -1987,7 +2021,7 @@ static void *cfq_init_queue(request_queue_t *q, elevator_t *e)
cfqd->idle_class_timer.function = cfq_idle_class_timer;
cfqd->idle_class_timer.data = (unsigned long) cfqd;
- INIT_WORK(&cfqd->unplug_work, cfq_kick_queue, q);
+ INIT_WORK(&cfqd->unplug_work, cfq_kick_queue);
cfqd->cfq_quantum = cfq_quantum;
cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0];
@@ -2118,6 +2152,7 @@ static struct elevator_type iosched_cfq = {
.elevator_merge_fn = cfq_merge,
.elevator_merged_fn = cfq_merged_request,
.elevator_merge_req_fn = cfq_merged_requests,
+ .elevator_allow_merge_fn = cfq_allow_merge,
.elevator_dispatch_fn = cfq_dispatch_requests,
.elevator_add_req_fn = cfq_insert_request,
.elevator_activate_req_fn = cfq_activate_request,