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Revert "Seperate read and write statistics of in_flight requests"

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This reverts commit a9327cac44.

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:
[a9327cac44] 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>
This commit is contained in:
Jens Axboe
2009-10-04 21:04:38 +02:00
parent e00c54c36a
commit 0f78ab9899
6 changed files with 19 additions and 42 deletions
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21
include/linux/genhd.h
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@ -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);