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block: move stats from disk to part0

Move stats related fields - stamp, in_flight, dkstats - from disk to
part0 and unify stat handling such that...

* part_stat_*() now updates part0 together if the specified partition
  is not part0.  ie. part_stat_*() are now essentially all_stat_*().

* {disk|all}_stat_*() are gone.

* part_round_stats() is updated similary.  It handles part0 stats
  automatically and disk_round_stats() is killed.

* part_{inc|dec}_in_fligh() is implemented which automatically updates
  part0 stats for parts other than part0.

* disk_map_sector_rcu() is updated to return part0 if no part matches.
  Combined with the above changes, this makes NULL special case
  handling in callers unnecessary.

* Separate stats show code paths for disk are collapsed into part
  stats show code paths.

* Rename disk_stat_lock/unlock() to part_stat_lock/unlock()

While at it, reposition stat handling macros a bit and add missing
parentheses around macro parameters.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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1 parent eddb2e2 commit 074a7aca7afa6f230104e8e65eba3420263714a5 @htejun htejun committed with Jens Axboe Aug 25, 2008
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@@ -61,21 +61,17 @@ static void drive_stat_acct(struct request *rq, int new_io)
if (!blk_fs_request(rq) || !rq->rq_disk)
return;
- cpu = disk_stat_lock();
+ cpu = part_stat_lock();
part = disk_map_sector_rcu(rq->rq_disk, rq->sector);
if (!new_io)
- all_stat_inc(cpu, rq->rq_disk, part, merges[rw], rq->sector);
+ part_stat_inc(cpu, part, merges[rw]);
else {
- disk_round_stats(cpu, rq->rq_disk);
- rq->rq_disk->in_flight++;
- if (part) {
- part_round_stats(cpu, part);
- part->in_flight++;
- }
+ part_round_stats(cpu, part);
+ part_inc_in_flight(part);
}
- disk_stat_unlock();
+ part_stat_unlock();
}
void blk_queue_congestion_threshold(struct request_queue *q)
@@ -983,8 +979,22 @@ static inline void add_request(struct request_queue *q, struct request *req)
__elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0);
}
-/*
- * disk_round_stats() - Round off the performance stats on a struct
+static void part_round_stats_single(int cpu, struct hd_struct *part,
+ unsigned long now)
+{
+ if (now == part->stamp)
+ return;
+
+ if (part->in_flight) {
+ __part_stat_add(cpu, part, time_in_queue,
+ part->in_flight * (now - part->stamp));
+ __part_stat_add(cpu, part, io_ticks, (now - part->stamp));
+ }
+ part->stamp = now;
+}
+
+/**
+ * part_round_stats() - Round off the performance stats on a struct
* disk_stats.
*
* The average IO queue length and utilisation statistics are maintained
@@ -998,36 +1008,15 @@ static inline void add_request(struct request_queue *q, struct request *req)
* /proc/diskstats. This accounts immediately for all queue usage up to
* the current jiffies and restarts the counters again.
*/
-void disk_round_stats(int cpu, struct gendisk *disk)
-{
- unsigned long now = jiffies;
-
- if (now == disk->stamp)
- return;
-
- if (disk->in_flight) {
- disk_stat_add(cpu, disk, time_in_queue,
- disk->in_flight * (now - disk->stamp));
- disk_stat_add(cpu, disk, io_ticks, (now - disk->stamp));
- }
- disk->stamp = now;
-}
-EXPORT_SYMBOL_GPL(disk_round_stats);
-
void part_round_stats(int cpu, struct hd_struct *part)
{
unsigned long now = jiffies;
- if (now == part->stamp)
- return;
-
- if (part->in_flight) {
- part_stat_add(cpu, part, time_in_queue,
- part->in_flight * (now - part->stamp));
- part_stat_add(cpu, part, io_ticks, (now - part->stamp));
- }
- part->stamp = now;
+ if (part->partno)
+ part_round_stats_single(cpu, &part_to_disk(part)->part0, now);
+ part_round_stats_single(cpu, part, now);
}
+EXPORT_SYMBOL_GPL(part_round_stats);
/*
* queue lock must be held
@@ -1567,11 +1556,10 @@ static int __end_that_request_first(struct request *req, int error,
struct hd_struct *part;
int cpu;
- cpu = disk_stat_lock();
+ cpu = part_stat_lock();
part = disk_map_sector_rcu(req->rq_disk, req->sector);
- all_stat_add(cpu, req->rq_disk, part, sectors[rw],
- nr_bytes >> 9, req->sector);
- disk_stat_unlock();
+ part_stat_add(cpu, part, sectors[rw], nr_bytes >> 9);
+ part_stat_unlock();
}
total_bytes = bio_nbytes = 0;
@@ -1758,19 +1746,15 @@ static void end_that_request_last(struct request *req, int error)
struct hd_struct *part;
int cpu;
- cpu = disk_stat_lock();
+ cpu = part_stat_lock();
part = disk_map_sector_rcu(disk, req->sector);
- all_stat_inc(cpu, disk, part, ios[rw], req->sector);
- all_stat_add(cpu, disk, part, ticks[rw], duration, req->sector);
- disk_round_stats(cpu, disk);
- disk->in_flight--;
- if (part) {
- part_round_stats(cpu, part);
- part->in_flight--;
- }
+ 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);
- disk_stat_unlock();
+ part_stat_unlock();
}
if (req->end_io)
View
@@ -390,17 +390,13 @@ static int attempt_merge(struct request_queue *q, struct request *req,
struct hd_struct *part;
int cpu;
- cpu = disk_stat_lock();
+ cpu = part_stat_lock();
part = disk_map_sector_rcu(req->rq_disk, req->sector);
- disk_round_stats(cpu, req->rq_disk);
- req->rq_disk->in_flight--;
- if (part) {
- part_round_stats(cpu, part);
- part->in_flight--;
- }
+ part_round_stats(cpu, part);
+ part_dec_in_flight(part);
- disk_stat_unlock();
+ part_stat_unlock();
}
req->ioprio = ioprio_best(req->ioprio, next->ioprio);
View
@@ -176,7 +176,7 @@ EXPORT_SYMBOL_GPL(disk_part_iter_exit);
* while preemption is disabled.
*
* RETURNS:
- * Found partition on success, NULL if there's no matching partition.
+ * Found partition on success, part0 is returned if no partition matches
*/
struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
{
@@ -189,7 +189,7 @@ struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
sector < part->start_sect + part->nr_sects)
return part;
}
- return NULL;
+ return &disk->part0;
}
EXPORT_SYMBOL_GPL(disk_map_sector_rcu);
@@ -580,24 +580,24 @@ void __init printk_all_partitions(void)
* numbers in hex - the same format as the root=
* option takes.
*/
- printk("%s %10llu %s",
- bdevt_str(disk_devt(disk), devt_buf),
- (unsigned long long)get_capacity(disk) >> 1,
- disk_name(disk, 0, name_buf));
- if (disk->driverfs_dev != NULL &&
- disk->driverfs_dev->driver != NULL)
- printk(" driver: %s\n",
- disk->driverfs_dev->driver->name);
- else
- printk(" (driver?)\n");
+ disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
+ while ((part = disk_part_iter_next(&piter))) {
+ bool is_part0 = part == &disk->part0;
- /* now show the partitions */
- disk_part_iter_init(&piter, disk, 0);
- while ((part = disk_part_iter_next(&piter)))
- printk(" %s %10llu %s\n",
+ printk("%s%s %10llu %s", is_part0 ? "" : " ",
bdevt_str(part_devt(part), devt_buf),
(unsigned long long)part->nr_sects >> 1,
disk_name(disk, part->partno, name_buf));
+ if (is_part0) {
+ if (disk->driverfs_dev != NULL &&
+ disk->driverfs_dev->driver != NULL)
+ printk(" driver: %s\n",
+ disk->driverfs_dev->driver->name);
+ else
+ printk(" (driver?)\n");
+ } else
+ printk("\n");
+ }
disk_part_iter_exit(&piter);
}
class_dev_iter_exit(&iter);
@@ -674,12 +674,7 @@ static int show_partition(struct seq_file *seqf, void *v)
return 0;
/* show the full disk and all non-0 size partitions of it */
- seq_printf(seqf, "%4d %7d %10llu %s\n",
- MAJOR(disk_devt(sgp)), MINOR(disk_devt(sgp)),
- (unsigned long long)get_capacity(sgp) >> 1,
- disk_name(sgp, 0, buf));
-
- disk_part_iter_init(&piter, sgp, 0);
+ disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0);
while ((part = disk_part_iter_next(&piter)))
seq_printf(seqf, "%4d %7d %10llu %s\n",
MAJOR(part_devt(part)), MINOR(part_devt(part)),
@@ -768,40 +763,13 @@ static ssize_t disk_capability_show(struct device *dev,
return sprintf(buf, "%x\n", disk->flags);
}
-static ssize_t disk_stat_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct gendisk *disk = dev_to_disk(dev);
- int cpu;
-
- cpu = disk_stat_lock();
- disk_round_stats(cpu, disk);
- disk_stat_unlock();
- return sprintf(buf,
- "%8lu %8lu %8llu %8u "
- "%8lu %8lu %8llu %8u "
- "%8u %8u %8u"
- "\n",
- disk_stat_read(disk, ios[READ]),
- disk_stat_read(disk, merges[READ]),
- (unsigned long long)disk_stat_read(disk, sectors[READ]),
- jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
- disk_stat_read(disk, ios[WRITE]),
- disk_stat_read(disk, merges[WRITE]),
- (unsigned long long)disk_stat_read(disk, sectors[WRITE]),
- jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
- disk->in_flight,
- jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
- jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
-}
-
static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL);
static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
-static DEVICE_ATTR(stat, S_IRUGO, disk_stat_show, NULL);
+static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
#ifdef CONFIG_FAIL_MAKE_REQUEST
static struct device_attribute dev_attr_fail =
__ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
@@ -836,7 +804,7 @@ static void disk_release(struct device *dev)
kfree(disk->random);
kfree(disk->__part);
- free_disk_stats(disk);
+ free_part_stats(&disk->part0);
kfree(disk);
}
struct class block_class = {
@@ -873,28 +841,11 @@ static int diskstats_show(struct seq_file *seqf, void *v)
"\n\n");
*/
- cpu = disk_stat_lock();
- disk_round_stats(cpu, gp);
- disk_stat_unlock();
- seq_printf(seqf, "%4d %7d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
- MAJOR(disk_devt(gp)), MINOR(disk_devt(gp)),
- disk_name(gp, 0, buf),
- disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
- (unsigned long long)disk_stat_read(gp, sectors[0]),
- jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
- disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
- (unsigned long long)disk_stat_read(gp, sectors[1]),
- jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
- gp->in_flight,
- jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
- jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
-
- /* now show all non-0 size partitions of it */
- disk_part_iter_init(&piter, gp, 0);
+ disk_part_iter_init(&piter, gp, DISK_PITER_INCL_PART0);
while ((hd = disk_part_iter_next(&piter))) {
- cpu = disk_stat_lock();
+ cpu = part_stat_lock();
part_round_stats(cpu, hd);
- disk_stat_unlock();
+ part_stat_unlock();
seq_printf(seqf, "%4d %7d %s %lu %lu %llu "
"%u %lu %lu %llu %u %u %u %u\n",
MAJOR(part_devt(hd)), MINOR(part_devt(hd)),
@@ -1000,15 +951,15 @@ struct gendisk *alloc_disk_ext_node(int minors, int ext_minors, int node_id)
int tot_minors = minors + ext_minors;
int size = tot_minors * sizeof(struct hd_struct *);
- if (!init_disk_stats(disk)) {
+ if (!init_part_stats(&disk->part0)) {
kfree(disk);
return NULL;
}
disk->__part = kmalloc_node(size, GFP_KERNEL | __GFP_ZERO,
node_id);
if (!disk->__part) {
- free_disk_stats(disk);
+ free_part_stats(&disk->part0);
kfree(disk);
return NULL;
}
@@ -758,15 +758,15 @@ diskstats(struct gendisk *disk, struct bio *bio, ulong duration, sector_t sector
struct hd_struct *part;
int cpu;
- cpu = disk_stat_lock();
+ cpu = part_stat_lock();
part = disk_map_sector_rcu(disk, sector);
- all_stat_inc(cpu, disk, part, ios[rw], sector);
- all_stat_add(cpu, disk, part, ticks[rw], duration, sector);
- all_stat_add(cpu, disk, part, sectors[rw], n_sect, sector);
- all_stat_add(cpu, disk, part, io_ticks, duration, sector);
+ part_stat_inc(cpu, part, ios[rw]);
+ part_stat_add(cpu, part, ticks[rw], duration);
+ part_stat_add(cpu, part, sectors[rw], n_sect);
+ part_stat_add(cpu, part, io_ticks, duration);
- disk_stat_unlock();
+ part_stat_unlock();
}
void
View
@@ -381,10 +381,10 @@ static void start_io_acct(struct dm_io *io)
io->start_time = jiffies;
- cpu = disk_stat_lock();
- disk_round_stats(cpu, dm_disk(md));
- disk_stat_unlock();
- dm_disk(md)->in_flight = atomic_inc_return(&md->pending);
+ cpu = part_stat_lock();
+ part_round_stats(cpu, &dm_disk(md)->part0);
+ part_stat_unlock();
+ dm_disk(md)->part0.in_flight = atomic_inc_return(&md->pending);
}
static int end_io_acct(struct dm_io *io)
@@ -395,12 +395,13 @@ static int end_io_acct(struct dm_io *io)
int pending, cpu;
int rw = bio_data_dir(bio);
- cpu = disk_stat_lock();
- disk_round_stats(cpu, dm_disk(md));
- disk_stat_add(cpu, dm_disk(md), ticks[rw], duration);
- disk_stat_unlock();
+ cpu = part_stat_lock();
+ part_round_stats(cpu, &dm_disk(md)->part0);
+ part_stat_add(cpu, &dm_disk(md)->part0, ticks[rw], duration);
+ part_stat_unlock();
- dm_disk(md)->in_flight = pending = atomic_dec_return(&md->pending);
+ dm_disk(md)->part0.in_flight = pending =
+ atomic_dec_return(&md->pending);
return !pending;
}
@@ -899,10 +900,10 @@ static int dm_request(struct request_queue *q, struct bio *bio)
down_read(&md->io_lock);
- cpu = disk_stat_lock();
- disk_stat_inc(cpu, dm_disk(md), ios[rw]);
- disk_stat_add(cpu, dm_disk(md), sectors[rw], bio_sectors(bio));
- disk_stat_unlock();
+ cpu = part_stat_lock();
+ part_stat_inc(cpu, &dm_disk(md)->part0, ios[rw]);
+ part_stat_add(cpu, &dm_disk(md)->part0, sectors[rw], bio_sectors(bio));
+ part_stat_unlock();
/*
* If we're suspended we have to queue
Oops, something went wrong. Retry.

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