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-rw-r--r--Documentation/block/biodoc.txt19
-rw-r--r--block/as-iosched.c116
-rw-r--r--block/blk-barrier.c3
-rw-r--r--block/blk-sysfs.c4
-rw-r--r--block/blk.h4
-rw-r--r--block/cfq-iosched.c270
-rw-r--r--block/elevator.c8
-rw-r--r--block/ioctl.c2
-rw-r--r--block/scsi_ioctl.c6
-rw-r--r--drivers/block/brd.c5
-rw-r--r--drivers/md/dm-bio-list.h117
-rw-r--r--drivers/md/dm-delay.c2
-rw-r--r--drivers/md/dm-mpath.c1
-rw-r--r--drivers/md/dm-raid1.c1
-rw-r--r--drivers/md/dm-region-hash.c1
-rw-r--r--drivers/md/dm-snap.c1
-rw-r--r--drivers/md/dm.c1
-rw-r--r--drivers/md/raid1.c1
-rw-r--r--drivers/md/raid10.c1
-rw-r--r--fs/bio.c18
-rw-r--r--fs/buffer.c11
-rw-r--r--fs/direct-io.c2
-rw-r--r--fs/ext4/extents.c2
-rw-r--r--fs/gfs2/ops_fstype.c5
-rw-r--r--fs/inode.c36
-rw-r--r--fs/ocfs2/file.c94
-rw-r--r--fs/pipe.c42
-rw-r--r--fs/splice.c371
-rw-r--r--include/linux/bio.h109
-rw-r--r--include/linux/fs.h64
-rw-r--r--include/linux/pipe_fs_i.h5
-rw-r--r--include/linux/splice.h12
-rw-r--r--kernel/power/swap.c2
33 files changed, 814 insertions, 522 deletions
diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt
index ecad6ee7570..6fab97ea7e6 100644
--- a/Documentation/block/biodoc.txt
+++ b/Documentation/block/biodoc.txt
@@ -1040,23 +1040,21 @@ Front merges are handled by the binary trees in AS and deadline schedulers.
iii. Plugging the queue to batch requests in anticipation of opportunities for
merge/sort optimizations
-This is just the same as in 2.4 so far, though per-device unplugging
-support is anticipated for 2.5. Also with a priority-based i/o scheduler,
-such decisions could be based on request priorities.
-
Plugging is an approach that the current i/o scheduling algorithm resorts to so
that it collects up enough requests in the queue to be able to take
advantage of the sorting/merging logic in the elevator. If the
queue is empty when a request comes in, then it plugs the request queue
-(sort of like plugging the bottom of a vessel to get fluid to build up)
+(sort of like plugging the bath tub of a vessel to get fluid to build up)
till it fills up with a few more requests, before starting to service
the requests. This provides an opportunity to merge/sort the requests before
passing them down to the device. There are various conditions when the queue is
unplugged (to open up the flow again), either through a scheduled task or
could be on demand. For example wait_on_buffer sets the unplugging going
-(by running tq_disk) so the read gets satisfied soon. So in the read case,
-the queue gets explicitly unplugged as part of waiting for completion,
-in fact all queues get unplugged as a side-effect.
+through sync_buffer() running blk_run_address_space(mapping). Or the caller
+can do it explicity through blk_unplug(bdev). So in the read case,
+the queue gets explicitly unplugged as part of waiting for completion on that
+buffer. For page driven IO, the address space ->sync_page() takes care of
+doing the blk_run_address_space().
Aside:
This is kind of controversial territory, as it's not clear if plugging is
@@ -1067,11 +1065,6 @@ Aside:
multi-page bios being queued in one shot, we may not need to wait to merge
a big request from the broken up pieces coming by.
- Per-queue granularity unplugging (still a Todo) may help reduce some of the
- concerns with just a single tq_disk flush approach. Something like
- blk_kick_queue() to unplug a specific queue (right away ?)
- or optionally, all queues, is in the plan.
-
4.4 I/O contexts
I/O contexts provide a dynamically allocated per process data area. They may
be used in I/O schedulers, and in the block layer (could be used for IO statis,
diff --git a/block/as-iosched.c b/block/as-iosched.c
index 631f6f44460..c48fa670d22 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -17,9 +17,6 @@
#include <linux/rbtree.h>
#include <linux/interrupt.h>
-#define REQ_SYNC 1
-#define REQ_ASYNC 0
-
/*
* See Documentation/block/as-iosched.txt
*/
@@ -93,7 +90,7 @@ struct as_data {
struct list_head fifo_list[2];
struct request *next_rq[2]; /* next in sort order */
- sector_t last_sector[2]; /* last REQ_SYNC & REQ_ASYNC sectors */
+ sector_t last_sector[2]; /* last SYNC & ASYNC sectors */
unsigned long exit_prob; /* probability a task will exit while
being waited on */
@@ -109,7 +106,7 @@ struct as_data {
unsigned long last_check_fifo[2];
int changed_batch; /* 1: waiting for old batch to end */
int new_batch; /* 1: waiting on first read complete */
- int batch_data_dir; /* current batch REQ_SYNC / REQ_ASYNC */
+ int batch_data_dir; /* current batch SYNC / ASYNC */
int write_batch_count; /* max # of reqs in a write batch */
int current_write_count; /* how many requests left this batch */
int write_batch_idled; /* has the write batch gone idle? */
@@ -554,7 +551,7 @@ static void as_update_iohist(struct as_data *ad, struct as_io_context *aic,
if (aic == NULL)
return;
- if (data_dir == REQ_SYNC) {
+ if (data_dir == BLK_RW_SYNC) {
unsigned long in_flight = atomic_read(&aic->nr_queued)
+ atomic_read(&aic->nr_dispatched);
spin_lock(&aic->lock);
@@ -811,7 +808,7 @@ static void as_update_rq(struct as_data *ad, struct request *rq)
*/
static void update_write_batch(struct as_data *ad)
{
- unsigned long batch = ad->batch_expire[REQ_ASYNC];
+ unsigned long batch = ad->batch_expire[BLK_RW_ASYNC];
long write_time;
write_time = (jiffies - ad->current_batch_expires) + batch;
@@ -855,7 +852,7 @@ static void as_completed_request(struct request_queue *q, struct request *rq)
kblockd_schedule_work(q, &ad->antic_work);
ad->changed_batch = 0;
- if (ad->batch_data_dir == REQ_SYNC)
+ if (ad->batch_data_dir == BLK_RW_SYNC)
ad->new_batch = 1;
}
WARN_ON(ad->nr_dispatched == 0);
@@ -869,7 +866,7 @@ static void as_completed_request(struct request_queue *q, struct request *rq)
if (ad->new_batch && ad->batch_data_dir == rq_is_sync(rq)) {
update_write_batch(ad);
ad->current_batch_expires = jiffies +
- ad->batch_expire[REQ_SYNC];
+ ad->batch_expire[BLK_RW_SYNC];
ad->new_batch = 0;
}
@@ -960,7 +957,7 @@ static inline int as_batch_expired(struct as_data *ad)
if (ad->changed_batch || ad->new_batch)
return 0;
- if (ad->batch_data_dir == REQ_SYNC)
+ if (ad->batch_data_dir == BLK_RW_SYNC)
/* TODO! add a check so a complete fifo gets written? */
return time_after(jiffies, ad->current_batch_expires);
@@ -986,7 +983,7 @@ static void as_move_to_dispatch(struct as_data *ad, struct request *rq)
*/
ad->last_sector[data_dir] = rq->sector + rq->nr_sectors;
- if (data_dir == REQ_SYNC) {
+ if (data_dir == BLK_RW_SYNC) {
struct io_context *ioc = RQ_IOC(rq);
/* In case we have to anticipate after this */
copy_io_context(&ad->io_context, &ioc);
@@ -1025,41 +1022,41 @@ static void as_move_to_dispatch(struct as_data *ad, struct request *rq)
static int as_dispatch_request(struct request_queue *q, int force)
{
struct as_data *ad = q->elevator->elevator_data;
- const int reads = !list_empty(&ad->fifo_list[REQ_SYNC]);
- const int writes = !list_empty(&ad->fifo_list[REQ_ASYNC]);
+ const int reads = !list_empty(&ad->fifo_list[BLK_RW_SYNC]);
+ const int writes = !list_empty(&ad->fifo_list[BLK_RW_ASYNC]);
struct request *rq;
if (unlikely(force)) {
/*
* Forced dispatch, accounting is useless. Reset
* accounting states and dump fifo_lists. Note that
- * batch_data_dir is reset to REQ_SYNC to avoid
+ * batch_data_dir is reset to BLK_RW_SYNC to avoid
* screwing write batch accounting as write batch
* accounting occurs on W->R transition.
*/
int dispatched = 0;
- ad->batch_data_dir = REQ_SYNC;
+ ad->batch_data_dir = BLK_RW_SYNC;
ad->changed_batch = 0;
ad->new_batch = 0;
- while (ad->next_rq[REQ_SYNC]) {
- as_move_to_dispatch(ad, ad->next_rq[REQ_SYNC]);
+ while (ad->next_rq[BLK_RW_SYNC]) {
+ as_move_to_dispatch(ad, ad->next_rq[BLK_RW_SYNC]);
dispatched++;
}
- ad->last_check_fifo[REQ_SYNC] = jiffies;
+ ad->last_check_fifo[BLK_RW_SYNC] = jiffies;
- while (ad->next_rq[REQ_ASYNC]) {
- as_move_to_dispatch(ad, ad->next_rq[REQ_ASYNC]);
+ while (ad->next_rq[BLK_RW_ASYNC]) {
+ as_move_to_dispatch(ad, ad->next_rq[BLK_RW_ASYNC]);
dispatched++;
}
- ad->last_check_fifo[REQ_ASYNC] = jiffies;
+ ad->last_check_fifo[BLK_RW_ASYNC] = jiffies;
return dispatched;
}
/* Signal that the write batch was uncontended, so we can't time it */
- if (ad->batch_data_dir == REQ_ASYNC && !reads) {
+ if (ad->batch_data_dir == BLK_RW_ASYNC && !reads) {
if (ad->current_write_count == 0 || !writes)
ad->write_batch_idled = 1;
}
@@ -1076,8 +1073,8 @@ static int as_dispatch_request(struct request_queue *q, int force)
*/
rq = ad->next_rq[ad->batch_data_dir];
- if (ad->batch_data_dir == REQ_SYNC && ad->antic_expire) {
- if (as_fifo_expired(ad, REQ_SYNC))
+ if (ad->batch_data_dir == BLK_RW_SYNC && ad->antic_expire) {
+ if (as_fifo_expired(ad, BLK_RW_SYNC))
goto fifo_expired;
if (as_can_anticipate(ad, rq)) {
@@ -1090,7 +1087,7 @@ static int as_dispatch_request(struct request_queue *q, int force)
/* we have a "next request" */
if (reads && !writes)
ad->current_batch_expires =
- jiffies + ad->batch_expire[REQ_SYNC];
+ jiffies + ad->batch_expire[BLK_RW_SYNC];
goto dispatch_request;
}
}
@@ -1101,20 +1098,20 @@ static int as_dispatch_request(struct request_queue *q, int force)
*/
if (reads) {
- BUG_ON(RB_EMPTY_ROOT(&ad->sort_list[REQ_SYNC]));
+ BUG_ON(RB_EMPTY_ROOT(&ad->sort_list[BLK_RW_SYNC]));
- if (writes && ad->batch_data_dir == REQ_SYNC)
+ if (writes && ad->batch_data_dir == BLK_RW_SYNC)
/*
* Last batch was a read, switch to writes
*/
goto dispatch_writes;
- if (ad->batch_data_dir == REQ_ASYNC) {
+ if (ad->batch_data_dir == BLK_RW_ASYNC) {
WARN_ON(ad->new_batch);
ad->changed_batch = 1;
}
- ad->batch_data_dir = REQ_SYNC;
- rq = rq_entry_fifo(ad->fifo_list[REQ_SYNC].next);
+ ad->batch_data_dir = BLK_RW_SYNC;
+ rq = rq_entry_fifo(ad->fifo_list[BLK_RW_SYNC].next);
ad->last_check_fifo[ad->batch_data_dir] = jiffies;
goto dispatch_request;
}
@@ -1125,9 +1122,9 @@ static int as_dispatch_request(struct request_queue *q, int force)
if (writes) {
dispatch_writes:
- BUG_ON(RB_EMPTY_ROOT(&ad->sort_list[REQ_ASYNC]));
+ BUG_ON(RB_EMPTY_ROOT(&ad->sort_list[BLK_RW_ASYNC]));
- if (ad->batch_data_dir == REQ_SYNC) {
+ if (ad->batch_data_dir == BLK_RW_SYNC) {
ad->changed_batch = 1;
/*
@@ -1137,11 +1134,11 @@ dispatch_writes:
*/
ad->new_batch = 0;
}
- ad->batch_data_dir = REQ_ASYNC;
+ ad->batch_data_dir = BLK_RW_ASYNC;
ad->current_write_count = ad->write_batch_count;
ad->write_batch_idled = 0;
- rq = rq_entry_fifo(ad->fifo_list[REQ_ASYNC].next);
- ad->last_check_fifo[REQ_ASYNC] = jiffies;
+ rq = rq_entry_fifo(ad->fifo_list[BLK_RW_ASYNC].next);
+ ad->last_check_fifo[BLK_RW_ASYNC] = jiffies;
goto dispatch_request;
}
@@ -1164,9 +1161,9 @@ fifo_expired:
if (ad->nr_dispatched)
return 0;
- if (ad->batch_data_dir == REQ_ASYNC)
+ if (ad->batch_data_dir == BLK_RW_ASYNC)
ad->current_batch_expires = jiffies +
- ad->batch_expire[REQ_ASYNC];
+ ad->batch_expire[BLK_RW_ASYNC];
else
ad->new_batch = 1;
@@ -1238,8 +1235,8 @@ static int as_queue_empty(struct request_queue *q)
{
struct as_data *ad = q->elevator->elevator_data;
- return list_empty(&ad->fifo_list[REQ_ASYNC])
- && list_empty(&ad->fifo_list[REQ_SYNC]);
+ return list_empty(&ad->fifo_list[BLK_RW_ASYNC])
+ && list_empty(&ad->fifo_list[BLK_RW_SYNC]);
}
static int
@@ -1346,8 +1343,8 @@ static void as_exit_queue(struct elevator_queue *e)
del_timer_sync(&ad->antic_timer);
cancel_work_sync(&ad->antic_work);
- BUG_ON(!list_empty(&ad->fifo_list[REQ_SYNC]));
- BUG_ON(!list_empty(&ad->fifo_list[REQ_ASYNC]));
+ BUG_ON(!list_empty(&ad->fifo_list[BLK_RW_SYNC]));
+ BUG_ON(!list_empty(&ad->fifo_list[BLK_RW_ASYNC]));
put_io_context(ad->io_context);
kfree(ad);
@@ -1372,18 +1369,18 @@ static void *as_init_queue(struct request_queue *q)
init_timer(&ad->antic_timer);
INIT_WORK(&ad->antic_work, as_work_handler);
- INIT_LIST_HEAD(&ad->fifo_list[REQ_SYNC]);
- INIT_LIST_HEAD(&ad->fifo_list[REQ_ASYNC]);
- ad->sort_list[REQ_SYNC] = RB_ROOT;
- ad->sort_list[REQ_ASYNC] = RB_ROOT;
- ad->fifo_expire[REQ_SYNC] = default_read_expire;
- ad->fifo_expire[REQ_ASYNC] = default_write_expire;
+ INIT_LIST_HEAD(&ad->fifo_list[BLK_RW_SYNC]);
+ INIT_LIST_HEAD(&ad->fifo_list[BLK_RW_ASYNC]);
+ ad->sort_list[BLK_RW_SYNC] = RB_ROOT;
+ ad->sort_list[BLK_RW_ASYNC] = RB_ROOT;
+ ad->fifo_expire[BLK_RW_SYNC] = default_read_expire;
+ ad->fifo_expire[BLK_RW_ASYNC] = default_write_expire;
ad->antic_expire = default_antic_expire;
- ad->batch_expire[REQ_SYNC] = default_read_batch_expire;
- ad->batch_expire[REQ_ASYNC] = default_write_batch_expire;
+ ad->batch_expire[BLK_RW_SYNC] = default_read_batch_expire;
+ ad->batch_expire[BLK_RW_ASYNC] = default_write_batch_expire;
- ad->current_batch_expires = jiffies + ad->batch_expire[REQ_SYNC];
- ad->write_batch_count = ad->batch_expire[REQ_ASYNC] / 10;
+ ad->current_batch_expires = jiffies + ad->batch_expire[BLK_RW_SYNC];
+ ad->write_batch_count = ad->batch_expire[BLK_RW_ASYNC] / 10;
if (ad->write_batch_count < 2)
ad->write_batch_count = 2;
@@ -1432,11 +1429,11 @@ static ssize_t __FUNC(struct elevator_queue *e, char *page) \
struct as_data *ad = e->elevator_data; \
return as_var_show(jiffies_to_msecs((__VAR)), (page)); \
}
-SHOW_FUNCTION(as_read_expire_show, ad->fifo_expire[REQ_SYNC]);
-SHOW_FUNCTION(as_write_expire_show, ad->fifo_expire[REQ_ASYNC]);
+SHOW_FUNCTION(as_read_expire_show, ad->fifo_expire[BLK_RW_SYNC]);
+SHOW_FUNCTION(as_write_expire_show, ad->fifo_expire[BLK_RW_ASYNC]);
SHOW_FUNCTION(as_antic_expire_show, ad->antic_expire);
-SHOW_FUNCTION(as_read_batch_expire_show, ad->batch_expire[REQ_SYNC]);
-SHOW_FUNCTION(as_write_batch_expire_show, ad->batch_expire[REQ_ASYNC]);
+SHOW_FUNCTION(as_read_batch_expire_show, ad->batch_expire[BLK_RW_SYNC]);
+SHOW_FUNCTION(as_write_batch_expire_show, ad->batch_expire[BLK_RW_ASYNC]);
#undef SHOW_FUNCTION
#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX) \
@@ -1451,13 +1448,14 @@ static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)
*(__PTR) = msecs_to_jiffies(*(__PTR)); \
return ret; \
}
-STORE_FUNCTION(as_read_expire_store, &ad->fifo_expire[REQ_SYNC], 0, INT_MAX);
-STORE_FUNCTION(as_write_expire_store, &ad->fifo_expire[REQ_ASYNC], 0, INT_MAX);
+STORE_FUNCTION(as_read_expire_store, &ad->fifo_expire[BLK_RW_SYNC], 0, INT_MAX);
+STORE_FUNCTION(as_write_expire_store,
+ &ad->fifo_expire[BLK_RW_ASYNC], 0, INT_MAX);
STORE_FUNCTION(as_antic_expire_store, &ad->antic_expire, 0, INT_MAX);
STORE_FUNCTION(as_read_batch_expire_store,
- &ad->batch_expire[REQ_SYNC], 0, INT_MAX);
+ &ad->batch_expire[BLK_RW_SYNC], 0, INT_MAX);
STORE_FUNCTION(as_write_batch_expire_store,
- &ad->batch_expire[REQ_ASYNC], 0, INT_MAX);
+ &ad->batch_expire[BLK_RW_ASYNC], 0, INT_MAX);
#undef STORE_FUNCTION
#define AS_ATTR(name) \
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index f7dae57e6ca..20b4111fa05 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -319,9 +319,6 @@ int blkdev_issue_flush(struct block_device *bdev, sector_t *error_sector)
return -ENXIO;
bio = bio_alloc(GFP_KERNEL, 0);
- if (!bio)
- return -ENOMEM;
-
bio->bi_end_io = bio_end_empty_barrier;
bio->bi_private = &wait;
bio->bi_bdev = bdev;
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 73f36beff5c..cac4e9febe6 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -209,14 +209,14 @@ static ssize_t queue_iostats_store(struct request_queue *q, const char *page,
ssize_t ret = queue_var_store(&stats, page, count);
spin_lock_irq(q->queue_lock);
- elv_quisce_start(q);
+ elv_quiesce_start(q);
if (stats)
queue_flag_set(QUEUE_FLAG_IO_STAT, q);
else
queue_flag_clear(QUEUE_FLAG_IO_STAT, q);
- elv_quisce_end(q);
+ elv_quiesce_end(q);
spin_unlock_irq(q->queue_lock);
return ret;
diff --git a/block/blk.h b/block/blk.h
index 24fcaeeaf62..5dfc41267a0 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -70,8 +70,8 @@ void blk_queue_congestion_threshold(struct request_queue *q);
int blk_dev_init(void);
-void elv_quisce_start(struct request_queue *q);
-void elv_quisce_end(struct request_queue *q);
+void elv_quiesce_start(struct request_queue *q);
+void elv_quiesce_end(struct request_queue *q);
/*
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index a4809de6fea..0d3b70de3d8 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -56,9 +56,6 @@ static DEFINE_SPINLOCK(ioc_gone_lock);
#define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE)
#define cfq_class_rt(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_RT)
-#define ASYNC (0)
-#define SYNC (1)
-
#define sample_valid(samples) ((samples) > 80)
/*
@@ -83,6 +80,14 @@ struct cfq_data {
* rr list of queues with requests and the count of them
*/
struct cfq_rb_root service_tree;
+
+ /*
+ * Each priority tree is sorted by next_request position. These
+ * trees are used when determining if two or more queues are
+ * interleaving requests (see cfq_close_cooperator).
+ */
+ struct rb_root prio_trees[CFQ_PRIO_LISTS];
+
unsigned int busy_queues;
/*
* Used to track any pending rt requests so we can pre-empt current
@@ -147,6 +152,8 @@ struct cfq_queue {
struct rb_node rb_node;
/* service_tree key */
unsigned long rb_key;
+ /* prio tree member */
+ struct rb_node p_node;
/* sorted list of pending requests */
struct rb_root sort_list;
/* if fifo isn't expired, next request to serve */
@@ -185,6 +192,7 @@ enum cfqq_state_flags {
CFQ_CFQQ_FLAG_prio_changed, /* task priority has changed */
CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */
CFQ_CFQQ_FLAG_sync, /* synchronous queue */
+ CFQ_CFQQ_FLAG_coop, /* has done a coop jump of the queue */
};
#define CFQ_CFQQ_FNS(name) \
@@ -211,6 +219,7 @@ CFQ_CFQQ_FNS(idle_window);
CFQ_CFQQ_FNS(prio_changed);
CFQ_CFQQ_FNS(slice_new);
CFQ_CFQQ_FNS(sync);
+CFQ_CFQQ_FNS(coop);
#undef CFQ_CFQQ_FNS
#define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \
@@ -419,13 +428,17 @@ static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root)
return NULL;
}
+static void rb_erase_init(struct rb_node *n, struct rb_root *root)
+{
+ rb_erase(n, root);
+ RB_CLEAR_NODE(n);
+}
+
static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root)
{
if (root->left == n)
root->left = NULL;
-
- rb_erase(n, &root->rb);
- RB_CLEAR_NODE(n);
+ rb_erase_init(n, &root->rb);
}
/*
@@ -470,8 +483,8 @@ static unsigned long cfq_slice_offset(struct cfq_data *cfqd,
* requests waiting to be processed. It is sorted in the order that
* we will service the queues.
*/
-static void cfq_service_tree_add(struct cfq_data *cfqd,
- struct cfq_queue *cfqq, int add_front)
+static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq,
+ int add_front)
{
struct rb_node **p, *parent;
struct cfq_queue *__cfqq;
@@ -544,6 +557,63 @@ static void cfq_service_tree_add(struct cfq_data *cfqd,
rb_insert_color(&cfqq->rb_node, &cfqd->service_tree.rb);
}
+static struct cfq_queue *
+cfq_prio_tree_lookup(struct cfq_data *cfqd, int ioprio, sector_t sector,
+ struct rb_node **ret_parent, struct rb_node ***rb_link)
+{
+ struct rb_root *root = &cfqd->prio_trees[ioprio];
+ struct rb_node **p, *parent;
+ struct cfq_queue *cfqq = NULL;
+
+ parent = NULL;
+ p = &root->rb_node;
+ while (*p) {
+ struct rb_node **n;
+
+ parent = *p;
+ cfqq = rb_entry(parent, struct cfq_queue, p_node);
+
+ /*
+ * Sort strictly based on sector. Smallest to the left,
+ * largest to the right.
+ */
+ if (sector > cfqq->next_rq->sector)
+ n = &(*p)->rb_right;
+ else if (sector < cfqq->next_rq->sector)
+ n = &(*p)->rb_left;
+ else
+ break;
+ p = n;
+ }
+
+ *ret_parent = parent;
+ if (rb_link)
+ *rb_link = p;
+ return NULL;
+}
+
+static void cfq_prio_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+ struct rb_root *root = &cfqd->prio_trees[cfqq->ioprio];
+ struct rb_node **p, *parent;
+ struct cfq_queue *__cfqq;
+
+ if (!RB_EMPTY_NODE(&cfqq->p_node))
+ rb_erase_init(&cfqq->p_node, root);
+
+ if (cfq_class_idle(cfqq))
+ return;
+ if (!cfqq->next_rq)
+ return;
+
+ __cfqq = cfq_prio_tree_lookup(cfqd, cfqq->ioprio, cfqq->next_rq->sector,
+ &parent, &p);
+ BUG_ON(__cfqq);
+
+ rb_link_node(&cfqq->p_node, parent, p);
+ rb_insert_color(&cfqq->p_node, root);
+}
+
/*
* Update cfqq's position in the service tree.
*/
@@ -552,8 +622,10 @@ static void cfq_resort_rr_list(struct cfq_data *cfqd, struct cfq_queue *cfqq)
/*
* Resorting requires the cfqq to be on the RR list already.
*/
- if (cfq_cfqq_on_rr(cfqq))
+ if (cfq_cfqq_on_rr(cfqq)) {
cfq_service_tree_add(cfqd, cfqq, 0);
+ cfq_prio_tree_add(cfqd, cfqq);
+ }
}
/*
@@ -584,6 +656,8 @@ static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
if (!RB_EMPTY_NODE(&cfqq->rb_node))
cfq_rb_erase(&cfqq->rb_node, &cfqd->service_tree);
+ if (!RB_EMPTY_NODE(&cfqq->p_node))
+ rb_erase_init(&cfqq->p_node, &cfqd->prio_trees[cfqq->ioprio]);
BUG_ON(!cfqd->busy_queues);
cfqd->busy_queues--;
@@ -613,7 +687,7 @@ static void cfq_add_rq_rb(struct request *rq)
{
struct cfq_queue *cfqq = RQ_CFQQ(rq);
struct cfq_data *cfqd = cfqq->cfqd;
- struct request *__alias;
+ struct request *__alias, *prev;
cfqq->queued[rq_is_sync(rq)]++;
@@ -630,7 +704,15 @@ static void cfq_add_rq_rb(struct request *rq)
/*
* check if this request is a better next-serve candidate
*/
+ prev = cfqq->next_rq;
cfqq->next_rq = cfq_choose_req(cfqd, cfqq->next_rq, rq);
+
+ /*
+ * adjust priority tree position, if ->next_rq changes
+ */
+ if (prev != cfqq->next_rq)
+ cfq_prio_tree_add(cfqd, cfqq);
+
BUG_ON(!cfqq->next_rq);
}
@@ -843,11 +925,15 @@ static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd)
/*
* Get and set a new active queue for service.
*/
-static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd)
+static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd,
+ struct cfq_queue *cfqq)
{
- struct cfq_queue *cfqq;
+ if (!cfqq) {
+ cfqq = cfq_get_next_queue(cfqd);
+ if (cfqq)
+ cfq_clear_cfqq_coop(cfqq);
+ }
- cfqq = cfq_get_next_queue(cfqd);
__cfq_set_active_queue(cfqd, cfqq);
return cfqq;
}
@@ -871,17 +957,89 @@ static inline int cfq_rq_close(struct cfq_data *cfqd, struct request *rq)
return cfq_dist_from_last(cfqd, rq) <= cic->seek_mean;
}
-static int cfq_close_cooperator(struct cfq_data *cfq_data,
- struct cfq_queue *cfqq)
+static struct cfq_queue *cfqq_close(struct cfq_data *cfqd,
+ struct cfq_queue *cur_cfqq)
+{
+ struct rb_root *root = &cfqd->prio_trees[cur_cfqq->ioprio];
+ struct rb_node *parent, *node;
+ struct cfq_queue *__cfqq;
+ sector_t sector = cfqd->last_position;
+
+ if (RB_EMPTY_ROOT(root))
+ return NULL;
+
+ /*
+ * First, if we find a request starting at the end of the last
+ * request, choose it.
+ */
+ __cfqq = cfq_prio_tree_lookup(cfqd, cur_cfqq->ioprio,
+ sector, &parent, NULL);
+ if (__cfqq)
+ return __cfqq;
+
+ /*
+ * If the exact sector wasn't found, the parent of the NULL leaf
+ * will contain the closest sector.
+ */
+ __cfqq = rb_entry(parent, struct cfq_queue, p_node);
+ if (cfq_rq_close(cfqd, __cfqq->next_rq))
+ return __cfqq;
+
+ if (__cfqq->next_rq->sector < sector)
+ node = rb_next(&__cfqq->p_node);
+ else
+ node = rb_prev(&__cfqq->p_node);
+ if (!node)
+ return NULL;
+
+ __cfqq = rb_entry(node, struct cfq_queue, p_node);
+ if (cfq_rq_close(cfqd, __cfqq->next_rq))
+ return __cfqq;
+
+ return NULL;
+}
+
+/*
+ * cfqd - obvious
+ * cur_cfqq - passed in so that we don't decide that the current queue is
+ * closely cooperating with itself.
+ *
+ * So, basically we're assuming that that cur_cfqq has dispatched at least
+ * one request, and that cfqd->last_position reflects a position on the disk
+ * associated with the I/O issued by cur_cfqq. I'm not sure this is a valid
+ * assumption.
+ */
+static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd,
+ struct cfq_queue *cur_cfqq,
+ int probe)
{
+ struct cfq_queue *cfqq;
+
+ /*
+ * A valid cfq_io_context is necessary to compare requests against
+ * the seek_mean of the current cfqq.
+ */
+ if (!cfqd->active_cic)
+ return NULL;
+
/*
* We should notice if some of the queues are cooperating, eg
* working closely on the same area of the disk. In that case,
* we can group them together and don't waste time idling.
*/
- return 0;
+ cfqq = cfqq_close(cfqd, cur_cfqq);
+ if (!cfqq)
+ return NULL;
+
+ if (cfq_cfqq_coop(cfqq))
+ return NULL;
+
+ if (!probe)
+ cfq_mark_cfqq_coop(cfqq);
+ return cfqq;
}
+
#define CIC_SEEKY(cic) ((cic)->seek_mean > (8 * 1024))
static void cfq_arm_slice_timer(struct cfq_data *cfqd)
@@ -920,13 +1078,6 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd)
if (!cic || !atomic_read(&cic->ioc->nr_tasks))
return;
- /*
- * See if this prio level has a good candidate
- */
- if (cfq_close_cooperator(cfqd, cfqq) &&
- (sample_valid(cic->ttime_samples) && cic->ttime_mean > 2))
- return;
-
cfq_mark_cfqq_wait_request(cfqq);
/*
@@ -939,7 +1090,7 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd)
sl = min(sl, msecs_to_jiffies(CFQ_MIN_TT));
mod_timer(&cfqd->idle_slice_timer, jiffies + sl);
- cfq_log(cfqd, "arm_idle: %lu", sl);
+ cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu", sl);
}
/*
@@ -1003,7 +1154,7 @@ cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
*/
static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd)
{
- struct cfq_queue *cfqq;
+ struct cfq_queue *cfqq, *new_cfqq = NULL;
cfqq = cfqd->active_queue;
if (!cfqq)
@@ -1037,6 +1188,16 @@ static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd)
goto keep_queue;
/*
+ * If another queue has a request waiting within our mean seek
+ * distance, let it run. The expire code will check for close
+ * cooperators and put the close queue at the front of the service
+ * tree.
+ */
+ new_cfqq = cfq_close_cooperator(cfqd, cfqq, 0);
+ if (new_cfqq)
+ goto expire;
+
+ /*
* No requests pending. If the active queue still has requests in
* flight or is idling for a new request, allow either of these
* conditions to happen (or time out) before selecting a new queue.
@@ -1050,7 +1211,7 @@ static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd)
expire:
cfq_slice_expired(cfqd, 0);
new_queue:
- cfqq = cfq_set_active_queue(cfqd);
+ cfqq = cfq_set_active_queue(cfqd, new_cfqq);
keep_queue:
return cfqq;
}
@@ -1333,14 +1494,14 @@ static void __cfq_exit_single_io_context(struct cfq_data *cfqd,
if (ioc->ioc_data == cic)
rcu_assign_pointer(ioc->ioc_data, NULL);
- if (cic->cfqq[ASYNC]) {
- cfq_exit_cfqq(cfqd, cic->cfqq[ASYNC]);
- cic->cfqq[ASYNC] = NULL;
+ if (cic->cfqq[BLK_RW_ASYNC]) {
+ cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_ASYNC]);
+ cic->cfqq[BLK_RW_ASYNC] = NULL;
}
- if (cic->cfqq[SYNC]) {
- cfq_exit_cfqq(cfqd, cic->cfqq[SYNC]);
- cic->cfqq[SYNC] = NULL;
+ if (cic->cfqq[BLK_RW_SYNC]) {
+ cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_SYNC]);
+ cic->cfqq[BLK_RW_SYNC] = NULL;
}
}
@@ -1449,17 +1610,18 @@ static void changed_ioprio(struct io_context *ioc, struct cfq_io_context *cic)
spin_lock_irqsave(cfqd->queue->queue_lock, flags);
- cfqq = cic->cfqq[ASYNC];
+ cfqq = cic->cfqq[BLK_RW_ASYNC];
if (cfqq) {
struct cfq_queue *new_cfqq;
- new_cfqq = cfq_get_queue(cfqd, ASYNC, cic->ioc, GFP_ATOMIC);
+ new_cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic->ioc,
+ GFP_ATOMIC);
if (new_cfqq) {
- cic->cfqq[ASYNC] = new_cfqq;
+ cic->cfqq[BLK_RW_ASYNC] = new_cfqq;
cfq_put_queue(cfqq);
}
}
- cfqq = cic->cfqq[SYNC];
+ cfqq = cic->cfqq[BLK_RW_SYNC];
if (cfqq)
cfq_mark_cfqq_prio_changed(cfqq);
@@ -1510,6 +1672,7 @@ retry:
}
RB_CLEAR_NODE(&cfqq->rb_node);
+ RB_CLEAR_NODE(&cfqq->p_node);
INIT_LIST_HEAD(&cfqq->fifo);
atomic_set(&cfqq->ref, 0);
@@ -1905,10 +2068,20 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
* Remember that we saw a request from this process, but
* don't start queuing just yet. Otherwise we risk seeing lots