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-rw-r--r--block/blk-core.c30
-rw-r--r--block/blk-ioc.c5
-rw-r--r--block/blk-merge.c3
-rw-r--r--block/cfq-iosched.c56
-rw-r--r--block/genhd.c6
5 files changed, 60 insertions, 40 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index 1510705..2f4002f 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -64,13 +64,27 @@ static void drive_stat_acct(struct request *rq, int new_io)
return;
cpu = part_stat_lock();
- part = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq));
- if (!new_io)
+ if (!new_io) {
+ part = rq->part;
part_stat_inc(cpu, part, merges[rw]);
- else {
+ } else {
+ part = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq));
+ if (!hd_struct_try_get(part)) {
+ /*
+ * The partition is already being removed,
+ * the request will be accounted on the disk only
+ *
+ * We take a reference on disk->part0 although that
+ * partition will never be deleted, so we can treat
+ * it as any other partition.
+ */
+ part = &rq->rq_disk->part0;
+ hd_struct_get(part);
+ }
part_round_stats(cpu, part);
part_inc_in_flight(part, rw);
+ rq->part = part;
}
part_stat_unlock();
@@ -128,6 +142,7 @@ void blk_rq_init(struct request_queue *q, struct request *rq)
rq->ref_count = 1;
rq->start_time = jiffies;
set_start_time_ns(rq);
+ rq->part = NULL;
}
EXPORT_SYMBOL(blk_rq_init);
@@ -1776,7 +1791,7 @@ static void blk_account_io_completion(struct request *req, unsigned int bytes)
int cpu;
cpu = part_stat_lock();
- part = disk_map_sector_rcu(req->rq_disk, blk_rq_pos(req));
+ part = req->part;
part_stat_add(cpu, part, sectors[rw], bytes >> 9);
part_stat_unlock();
}
@@ -1796,13 +1811,14 @@ static void blk_account_io_done(struct request *req)
int cpu;
cpu = part_stat_lock();
- part = disk_map_sector_rcu(req->rq_disk, blk_rq_pos(req));
+ part = req->part;
part_stat_inc(cpu, part, ios[rw]);
part_stat_add(cpu, part, ticks[rw], duration);
part_round_stats(cpu, part);
part_dec_in_flight(part, rw);
+ hd_struct_put(part);
part_stat_unlock();
}
}
@@ -2606,7 +2622,9 @@ int __init blk_dev_init(void)
BUILD_BUG_ON(__REQ_NR_BITS > 8 *
sizeof(((struct request *)0)->cmd_flags));
- kblockd_workqueue = create_workqueue("kblockd");
+ /* used for unplugging and affects IO latency/throughput - HIGHPRI */
+ kblockd_workqueue = alloc_workqueue("kblockd",
+ WQ_MEM_RECLAIM | WQ_HIGHPRI, 0);
if (!kblockd_workqueue)
panic("Failed to create kblockd\n");
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 3c7a339..b791022 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -64,7 +64,7 @@ static void cfq_exit(struct io_context *ioc)
rcu_read_unlock();
}
-/* Called by the exitting task */
+/* Called by the exiting task */
void exit_io_context(struct task_struct *task)
{
struct io_context *ioc;
@@ -74,10 +74,9 @@ void exit_io_context(struct task_struct *task)
task->io_context = NULL;
task_unlock(task);
- if (atomic_dec_and_test(&ioc->nr_tasks)) {
+ if (atomic_dec_and_test(&ioc->nr_tasks))
cfq_exit(ioc);
- }
put_io_context(ioc);
}
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 77b7c26..00b7d31 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -351,11 +351,12 @@ static void blk_account_io_merge(struct request *req)
int cpu;
cpu = part_stat_lock();
- part = disk_map_sector_rcu(req->rq_disk, blk_rq_pos(req));
+ part = req->part;
part_round_stats(cpu, part);
part_dec_in_flight(part, rq_data_dir(req));
+ hd_struct_put(part);
part_stat_unlock();
}
}
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 9b186fd..f083bda 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -96,7 +96,7 @@ struct cfq_rb_root {
*/
struct cfq_queue {
/* reference count */
- atomic_t ref;
+ int ref;
/* various state flags, see below */
unsigned int flags;
/* parent cfq_data */
@@ -207,7 +207,7 @@ struct cfq_group {
struct blkio_group blkg;
#ifdef CONFIG_CFQ_GROUP_IOSCHED
struct hlist_node cfqd_node;
- atomic_t ref;
+ int ref;
#endif
/* number of requests that are on the dispatch list or inside driver */
int dispatched;
@@ -1014,7 +1014,7 @@ cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create)
* elevator which will be dropped by either elevator exit
* or cgroup deletion path depending on who is exiting first.
*/
- atomic_set(&cfqg->ref, 1);
+ cfqg->ref = 1;
/*
* Add group onto cgroup list. It might happen that bdi->dev is
@@ -1059,7 +1059,7 @@ static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create)
static inline struct cfq_group *cfq_ref_get_cfqg(struct cfq_group *cfqg)
{
- atomic_inc(&cfqg->ref);
+ cfqg->ref++;
return cfqg;
}
@@ -1071,7 +1071,7 @@ static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg)
cfqq->cfqg = cfqg;
/* cfqq reference on cfqg */
- atomic_inc(&cfqq->cfqg->ref);
+ cfqq->cfqg->ref++;
}
static void cfq_put_cfqg(struct cfq_group *cfqg)
@@ -1079,8 +1079,9 @@ static void cfq_put_cfqg(struct cfq_group *cfqg)
struct cfq_rb_root *st;
int i, j;
- BUG_ON(atomic_read(&cfqg->ref) <= 0);
- if (!atomic_dec_and_test(&cfqg->ref))
+ BUG_ON(cfqg->ref <= 0);
+ cfqg->ref--;
+ if (cfqg->ref)
return;
for_each_cfqg_st(cfqg, i, j, st)
BUG_ON(!RB_EMPTY_ROOT(&st->rb));
@@ -1188,7 +1189,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
cfq_group_service_tree_del(cfqd, cfqq->cfqg);
cfqq->orig_cfqg = cfqq->cfqg;
cfqq->cfqg = &cfqd->root_group;
- atomic_inc(&cfqd->root_group.ref);
+ cfqd->root_group.ref++;
group_changed = 1;
} else if (!cfqd->cfq_group_isolation
&& cfqq_type(cfqq) == SYNC_WORKLOAD && cfqq->orig_cfqg) {
@@ -2025,7 +2026,7 @@ static int cfqq_process_refs(struct cfq_queue *cfqq)
int process_refs, io_refs;
io_refs = cfqq->allocated[READ] + cfqq->allocated[WRITE];
- process_refs = atomic_read(&cfqq->ref) - io_refs;
+ process_refs = cfqq->ref - io_refs;
BUG_ON(process_refs < 0);
return process_refs;
}
@@ -2065,10 +2066,10 @@ static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq)
*/
if (new_process_refs >= process_refs) {
cfqq->new_cfqq = new_cfqq;
- atomic_add(process_refs, &new_cfqq->ref);
+ new_cfqq->ref += process_refs;
} else {
new_cfqq->new_cfqq = cfqq;
- atomic_add(new_process_refs, &cfqq->ref);
+ cfqq->ref += new_process_refs;
}
}
@@ -2103,12 +2104,6 @@ static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg)
unsigned group_slice;
enum wl_prio_t original_prio = cfqd->serving_prio;
- if (!cfqg) {
- cfqd->serving_prio = IDLE_WORKLOAD;
- cfqd->workload_expires = jiffies + 1;
- return;
- }
-
/* Choose next priority. RT > BE > IDLE */
if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg))
cfqd->serving_prio = RT_WORKLOAD;
@@ -2538,9 +2533,10 @@ static void cfq_put_queue(struct cfq_queue *cfqq)
struct cfq_data *cfqd = cfqq->cfqd;
struct cfq_group *cfqg, *orig_cfqg;
- BUG_ON(atomic_read(&cfqq->ref) <= 0);
+ BUG_ON(cfqq->ref <= 0);
- if (!atomic_dec_and_test(&cfqq->ref))
+ cfqq->ref--;
+ if (cfqq->ref)
return;
cfq_log_cfqq(cfqd, cfqq, "put_queue");
@@ -2843,7 +2839,7 @@ static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
RB_CLEAR_NODE(&cfqq->p_node);
INIT_LIST_HEAD(&cfqq->fifo);
- atomic_set(&cfqq->ref, 0);
+ cfqq->ref = 0;
cfqq->cfqd = cfqd;
cfq_mark_cfqq_prio_changed(cfqq);
@@ -2979,11 +2975,11 @@ cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct io_context *ioc,
* pin the queue now that it's allocated, scheduler exit will prune it
*/
if (!is_sync && !(*async_cfqq)) {
- atomic_inc(&cfqq->ref);
+ cfqq->ref++;
*async_cfqq = cfqq;
}
- atomic_inc(&cfqq->ref);
+ cfqq->ref++;
return cfqq;
}
@@ -3685,13 +3681,13 @@ new_queue:
}
cfqq->allocated[rw]++;
- atomic_inc(&cfqq->ref);
-
- spin_unlock_irqrestore(q->queue_lock, flags);
-
+ cfqq->ref++;
rq->elevator_private = cic;
rq->elevator_private2 = cfqq;
rq->elevator_private3 = cfq_ref_get_cfqg(cfqq->cfqg);
+
+ spin_unlock_irqrestore(q->queue_lock, flags);
+
return 0;
queue_fail:
@@ -3866,6 +3862,10 @@ static void *cfq_init_queue(struct request_queue *q)
if (!cfqd)
return NULL;
+ /*
+ * Don't need take queue_lock in the routine, since we are
+ * initializing the ioscheduler, and nobody is using cfqd
+ */
cfqd->cic_index = i;
/* Init root service tree */
@@ -3885,7 +3885,7 @@ static void *cfq_init_queue(struct request_queue *q)
* Take a reference to root group which we never drop. This is just
* to make sure that cfq_put_cfqg() does not try to kfree root group
*/
- atomic_set(&cfqg->ref, 1);
+ cfqg->ref = 1;
rcu_read_lock();
cfq_blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg,
(void *)cfqd, 0);
@@ -3905,7 +3905,7 @@ static void *cfq_init_queue(struct request_queue *q)
* will not attempt to free it.
*/
cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0);
- atomic_inc(&cfqd->oom_cfqq.ref);
+ cfqd->oom_cfqq.ref++;
cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, &cfqd->root_group);
INIT_LIST_HEAD(&cfqd->cic_list);
diff --git a/block/genhd.c b/block/genhd.c
index 5465a82..6a5b772 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -244,7 +244,7 @@ static struct blk_major_name {
} *major_names[BLKDEV_MAJOR_HASH_SIZE];
/* index in the above - for now: assume no multimajor ranges */
-static inline int major_to_index(int major)
+static inline int major_to_index(unsigned major)
{
return major % BLKDEV_MAJOR_HASH_SIZE;
}
@@ -828,7 +828,7 @@ static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
static void *p;
p = disk_seqf_start(seqf, pos);
- if (!IS_ERR(p) && p && !*pos)
+ if (!IS_ERR_OR_NULL(p) && !*pos)
seq_puts(seqf, "major minor #blocks name\n\n");
return p;
}
@@ -1264,6 +1264,8 @@ struct gendisk *alloc_disk_node(int minors, int node_id)
}
disk->part_tbl->part[0] = &disk->part0;
+ hd_ref_init(&disk->part0);
+
disk->minors = minors;
rand_initialize_disk(disk);
disk_to_dev(disk)->class = &block_class;