kernel-hacking-2024-linux-s.../block
Jens Axboe 0f78ab9899 Revert "Seperate read and write statistics of in_flight requests"
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>
2009-10-04 21:04:38 +02:00
..
as-iosched.c
blk-barrier.c block: allow large discard requests 2009-10-01 21:19:34 +02:00
blk-core.c Revert "Seperate read and write statistics of in_flight requests" 2009-10-04 21:04:38 +02:00
blk-exec.c
blk-integrity.c
blk-ioc.c
blk-iopoll.c
blk-map.c
blk-merge.c Revert "Seperate read and write statistics of in_flight requests" 2009-10-04 21:04:38 +02:00
blk-settings.c block: allow large discard requests 2009-10-01 21:19:34 +02:00
blk-softirq.c
blk-sysfs.c Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfs 2009-10-01 21:15:46 +02:00
blk-tag.c
blk-timeout.c
blk.h
bsg.c Driver-Core: extend devnode callbacks to provide permissions 2009-09-19 12:50:38 -07:00
cfq-iosched.c cfq-iosched: don't delay async queue if it hasn't dispatched at all 2009-10-04 20:36:19 +02:00
compat_ioctl.c block: Topology ioctls 2009-10-03 20:52:01 +02:00
deadline-iosched.c
elevator.c
genhd.c Revert "Seperate read and write statistics of in_flight requests" 2009-10-04 21:04:38 +02:00
ioctl.c block: Topology ioctls 2009-10-03 20:52:01 +02:00
Kconfig
Kconfig.iosched
Makefile
noop-iosched.c
scsi_ioctl.c