1
linux/block
Nikanth Karthikesan 316d315bff block: Seperate read and write statistics of in_flight requests v2
Commit a9327cac44 added seperate read
and write statistics of in_flight requests. And exported the number
of read and write requests in progress seperately through sysfs.

But  Corrado Zoccolo <czoccolo@gmail.com> reported getting strange
output from "iostat -kx 2". Global values for service time and
utilization were garbage. For interval values, utilization was always
100%, and service time is higher than normal.

So this was reverted by commit 0f78ab9899

The problem was in part_round_stats_single(), I missed the following:
        if (now == part->stamp)
                return;

-       if (part->in_flight) {
+       if (part_in_flight(part)) {
                __part_stat_add(cpu, part, time_in_queue,
                                part_in_flight(part) * (now - part->stamp));
                __part_stat_add(cpu, part, io_ticks, (now - part->stamp));

With this chunk included, the reported regression gets fixed.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>

--
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-10-06 20:16:55 +02:00
..
as-iosched.c percpu: clean up percpu variable definitions 2009-06-24 15:13:48 +09:00
blk-barrier.c block: allow large discard requests 2009-10-01 21:19:34 +02:00
blk-core.c block: Seperate read and write statistics of in_flight requests v2 2009-10-06 20:16:55 +02:00
blk-exec.c block: don't set REQ_NOMERGE unnecessarily 2009-04-28 07:37:33 +02:00
blk-integrity.c block: fix improper kobject release in blk_integrity_unregister 2009-07-28 09:11:14 +02:00
blk-ioc.c block: prevent possible io_context->refcount overflow 2009-06-10 23:07:15 +02:00
blk-iopoll.c block: use interrupts disabled version of raise_softirq_irqoff() 2009-09-11 14:33:32 +02:00
blk-map.c block: Use accessor functions for queue limits 2009-05-22 23:22:54 +02:00
blk-merge.c block: Seperate read and write statistics of in_flight requests v2 2009-10-06 20:16:55 +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 block: change the tag sync vs async restriction logic 2009-05-20 08:54:31 +02:00
blk-timeout.c block: clean up misc stuff after block layer timeout conversion 2009-04-28 07:37:34 +02:00
blk.h block: implement mixed merge of different failfast requests 2009-09-11 14:33:30 +02:00
bsg.c Driver-Core: extend devnode callbacks to provide permissions 2009-09-19 12:50:38 -07:00
cfq-iosched.c block: get rid of kblock_schedule_delayed_work() 2009-10-05 11:03:58 +02:00
compat_ioctl.c block: Topology ioctls 2009-10-03 20:52:01 +02:00
deadline-iosched.c block: convert to pos and nr_sectors accessors 2009-05-11 09:50:54 +02:00
elevator.c bio: first step in sanitizing the bio->bi_rw flag testing 2009-09-11 14:33:31 +02:00
genhd.c block: Seperate read and write statistics of in_flight requests v2 2009-10-06 20:16:55 +02:00
ioctl.c block: Topology ioctls 2009-10-03 20:52:01 +02:00
Kconfig Make SCSI SG v4 driver enabled by default and remove EXPERIMENTAL dependency, since udev depends on BSG 2009-08-04 22:10:17 +02:00
Kconfig.iosched
Makefile block: add blk-iopoll, a NAPI like approach for block devices 2009-09-11 14:33:31 +02:00
noop-iosched.c
scsi_ioctl.c block: call blk_scsi_ioctl_init() 2009-07-10 20:31:53 +02:00