Messages in this thread | | | From | Nikanth Karthikesan <> | Subject | Re: [bisected] commit: a9327cac440be4d8333bba975cbbf76045096275 causes iostat output | Date | Tue, 6 Oct 2009 18:44:01 +0530 |
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On Monday 05 October 2009 00:36:53 Jens Axboe wrote: > On Sun, Oct 04 2009, Corrado Zoccolo wrote: > > Hi, > > 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. >
Thanks for reporting.
> I've reverted this commit since the next -rc is close, then we can debug > and potentially re-introduce this change after that. Thanks a lot for > reporting and bisecting it, too!
Sorry. I missed converting to 2 seperate variables at
@@ -1030,7 +1030,7 @@ static void part_round_stats_single(int cpu, struct hd_struct *part, 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));
which caused this regression. I would post the patch with this fix included.
Thanks Nikanth
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