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authorJens Axboe <jens.axboe@oracle.com>2009-10-04 21:04:38 +0200
committerJens Axboe <jens.axboe@oracle.com>2009-10-04 21:04:38 +0200
commit0f78ab9899e9d6acb09d5465def618704255963b (patch)
treeb92832da61ae4f4d712a33ae524c482e979be5ba
parente00c54c36ac2024c3a8a37432e2e2698ff849594 (diff)
downloadlinux-2.6.34-ux500-0f78ab9899e9d6acb09d5465def618704255963b.tar.gz
Revert "Seperate read and write statistics of in_flight requests"
This reverts commit a9327cac440be4d8333bba975cbbf76045096275. Corrado Zoccolo <czoccolo@gmail.com> reports: "with 2.6.32-rc1 I started getting the following strange output from "iostat -kx 2": Linux 2.6.31bisect (et2) 04/10/2009 _i686_ (2 CPU) avg-cpu: %user %nice %system %iowait %steal %idle 10,70 0,00 3,16 15,75 0,00 70,38 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 18,22 0,00 0,67 0,01 14,77 0,02 43,94 0,01 10,53 39043915,03 2629219,87 sdb 60,89 9,68 50,79 3,04 1724,43 50,52 65,95 0,70 13,06 488437,47 2629219,87 avg-cpu: %user %nice %system %iowait %steal %idle 2,72 0,00 0,74 0,00 0,00 96,53 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 100,00 sdb 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 100,00 avg-cpu: %user %nice %system %iowait %steal %idle 6,68 0,00 0,99 0,00 0,00 92,33 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 100,00 sdb 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 100,00 avg-cpu: %user %nice %system %iowait %steal %idle 4,40 0,00 0,73 1,47 0,00 93,40 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 100,00 sdb 0,00 4,00 0,00 3,00 0,00 28,00 18,67 0,06 19,50 333,33 100,00 Global values for service time and utilization are garbage. For interval values, utilization is always 100%, and service time is higher than normal. I bisected it down to: [a9327cac440be4d8333bba975cbbf76045096275] Seperate read and write statistics of in_flight requests and verified that reverting just that commit indeed solves the issue on 2.6.32-rc1." So until this is debugged, revert the bad commit. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
-rw-r--r--block/blk-core.c6
-rw-r--r--block/blk-merge.c2
-rw-r--r--block/genhd.c4
-rw-r--r--drivers/md/dm.c16
-rw-r--r--fs/partitions/check.c12
-rw-r--r--include/linux/genhd.h21
6 files changed, 19 insertions, 42 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index a8c7fbe52e2..81f34311659 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -70,7 +70,7 @@ static void drive_stat_acct(struct request *rq, int new_io)
part_stat_inc(cpu, part, merges[rw]);
else {
part_round_stats(cpu, part);
- part_inc_in_flight(part, rw);
+ part_inc_in_flight(part);
}
part_stat_unlock();
@@ -1032,7 +1032,7 @@ static void part_round_stats_single(int cpu, struct hd_struct *part,
if (part->in_flight) {
__part_stat_add(cpu, part, time_in_queue,
- part_in_flight(part) * (now - part->stamp));
+ part->in_flight * (now - part->stamp));
__part_stat_add(cpu, part, io_ticks, (now - part->stamp));
}
part->stamp = now;
@@ -1739,7 +1739,7 @@ static void blk_account_io_done(struct request *req)
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);
+ part_dec_in_flight(part);
part_stat_unlock();
}
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 99cb5cf1f44..b0de8574fdc 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -351,7 +351,7 @@ static void blk_account_io_merge(struct request *req)
part = disk_map_sector_rcu(req->rq_disk, blk_rq_pos(req));
part_round_stats(cpu, part);
- part_dec_in_flight(part, rq_data_dir(req));
+ part_dec_in_flight(part);
part_stat_unlock();
}
diff --git a/block/genhd.c b/block/genhd.c
index 517e4332cb3..5a0861da324 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -869,7 +869,6 @@ static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
static DEVICE_ATTR(alignment_offset, S_IRUGO, disk_alignment_offset_show, NULL);
static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
-static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_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);
@@ -889,7 +888,6 @@ static struct attribute *disk_attrs[] = {
&dev_attr_alignment_offset.attr,
&dev_attr_capability.attr,
&dev_attr_stat.attr,
- &dev_attr_inflight.attr,
#ifdef CONFIG_FAIL_MAKE_REQUEST
&dev_attr_fail.attr,
#endif
@@ -1055,7 +1053,7 @@ static int diskstats_show(struct seq_file *seqf, void *v)
part_stat_read(hd, merges[1]),
(unsigned long long)part_stat_read(hd, sectors[1]),
jiffies_to_msecs(part_stat_read(hd, ticks[1])),
- part_in_flight(hd),
+ hd->in_flight,
jiffies_to_msecs(part_stat_read(hd, io_ticks)),
jiffies_to_msecs(part_stat_read(hd, time_in_queue))
);
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 376f1ab48a2..23e76fe0d35 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -130,7 +130,7 @@ struct mapped_device {
/*
* A list of ios that arrived while we were suspended.
*/
- atomic_t pending[2];
+ atomic_t pending;
wait_queue_head_t wait;
struct work_struct work;
struct bio_list deferred;
@@ -453,14 +453,13 @@ static void start_io_acct(struct dm_io *io)
{
struct mapped_device *md = io->md;
int cpu;
- int rw = bio_data_dir(io->bio);
io->start_time = jiffies;
cpu = part_stat_lock();
part_round_stats(cpu, &dm_disk(md)->part0);
part_stat_unlock();
- dm_disk(md)->part0.in_flight[rw] = atomic_inc_return(&md->pending[rw]);
+ dm_disk(md)->part0.in_flight = atomic_inc_return(&md->pending);
}
static void end_io_acct(struct dm_io *io)
@@ -480,9 +479,8 @@ static void end_io_acct(struct dm_io *io)
* After this is decremented the bio must not be touched if it is
* a barrier.
*/
- dm_disk(md)->part0.in_flight[rw] = pending =
- atomic_dec_return(&md->pending[rw]);
- pending += atomic_read(&md->pending[rw^0x1]);
+ dm_disk(md)->part0.in_flight = pending =
+ atomic_dec_return(&md->pending);
/* nudge anyone waiting on suspend queue */
if (!pending)
@@ -1787,8 +1785,7 @@ static struct mapped_device *alloc_dev(int minor)
if (!md->disk)
goto bad_disk;
- atomic_set(&md->pending[0], 0);
- atomic_set(&md->pending[1], 0);
+ atomic_set(&md->pending, 0);
init_waitqueue_head(&md->wait);
INIT_WORK(&md->work, dm_wq_work);
init_waitqueue_head(&md->eventq);
@@ -2091,8 +2088,7 @@ static int dm_wait_for_completion(struct mapped_device *md, int interruptible)
break;
}
spin_unlock_irqrestore(q->queue_lock, flags);
- } else if (!atomic_read(&md->pending[0]) &&
- !atomic_read(&md->pending[1]))
+ } else if (!atomic_read(&md->pending))
break;
if (interruptible == TASK_INTERRUPTIBLE &&
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index 7b685e10cba..f38fee0311a 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -248,19 +248,11 @@ ssize_t part_stat_show(struct device *dev,
part_stat_read(p, merges[WRITE]),
(unsigned long long)part_stat_read(p, sectors[WRITE]),
jiffies_to_msecs(part_stat_read(p, ticks[WRITE])),
- part_in_flight(p),
+ p->in_flight,
jiffies_to_msecs(part_stat_read(p, io_ticks)),
jiffies_to_msecs(part_stat_read(p, time_in_queue)));
}
-ssize_t part_inflight_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct hd_struct *p = dev_to_part(dev);
-
- return sprintf(buf, "%8u %8u\n", p->in_flight[0], p->in_flight[1]);
-}
-
#ifdef CONFIG_FAIL_MAKE_REQUEST
ssize_t part_fail_show(struct device *dev,
struct device_attribute *attr, char *buf)
@@ -289,7 +281,6 @@ static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
static DEVICE_ATTR(alignment_offset, S_IRUGO, part_alignment_offset_show, NULL);
static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
-static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_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);
@@ -301,7 +292,6 @@ static struct attribute *part_attrs[] = {
&dev_attr_size.attr,
&dev_attr_alignment_offset.attr,
&dev_attr_stat.attr,
- &dev_attr_inflight.attr,
#ifdef CONFIG_FAIL_MAKE_REQUEST
&dev_attr_fail.attr,
#endif
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 297df45ffd0..7beaa21b388 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -98,7 +98,7 @@ struct hd_struct {
int make_it_fail;
#endif
unsigned long stamp;
- int in_flight[2];
+ int in_flight;
#ifdef CONFIG_SMP
struct disk_stats *dkstats;
#else
@@ -322,23 +322,18 @@ static inline void free_part_stats(struct hd_struct *part)
#define part_stat_sub(cpu, gendiskp, field, subnd) \
part_stat_add(cpu, gendiskp, field, -subnd)
-static inline void part_inc_in_flight(struct hd_struct *part, int rw)
+static inline void part_inc_in_flight(struct hd_struct *part)
{
- part->in_flight[rw]++;
+ part->in_flight++;
if (part->partno)
- part_to_disk(part)->part0.in_flight[rw]++;
+ part_to_disk(part)->part0.in_flight++;
}
-static inline void part_dec_in_flight(struct hd_struct *part, int rw)
+static inline void part_dec_in_flight(struct hd_struct *part)
{
- part->in_flight[rw]--;
+ part->in_flight--;
if (part->partno)
- part_to_disk(part)->part0.in_flight[rw]--;
-}
-
-static inline int part_in_flight(struct hd_struct *part)
-{
- return part->in_flight[0] + part->in_flight[1];
+ part_to_disk(part)->part0.in_flight--;
}
/* block/blk-core.c */
@@ -551,8 +546,6 @@ extern ssize_t part_size_show(struct device *dev,
struct device_attribute *attr, char *buf);
extern ssize_t part_stat_show(struct device *dev,
struct device_attribute *attr, char *buf);
-extern ssize_t part_inflight_show(struct device *dev,
- struct device_attribute *attr, char *buf);
#ifdef CONFIG_FAIL_MAKE_REQUEST
extern ssize_t part_fail_show(struct device *dev,
struct device_attribute *attr, char *buf);