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>
diff --git a/block/blk-core.c b/block/blk-core.c
index a8c7fbe..81f3431 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -70,7 +70,7 @@
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 @@
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 @@
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 99cb5cf..b0de857 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -351,7 +351,7 @@
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 517e433..5a0861d 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -869,7 +869,6 @@
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 @@
&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 @@
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 376f1ab..23e76fe 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -130,7 +130,7 @@
/*
* 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 @@
{
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 @@
* 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 @@
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 @@
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 7b685e1..f38fee0 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -248,19 +248,11 @@
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(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 @@
&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 297df45..7beaa21 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -98,7 +98,7 @@
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 @@
#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 @@
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);
