Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 2 Apr 2010 08:45:14 +0200 | From | Jens Axboe <> | Subject | Re: [PATCH 0/3] blkio: IO controller stats |
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On Thu, Apr 01 2010, Divyesh Shah wrote: > The following series implements some additional stats for IO controller. > > These stats have helped us debug issues with earlier IO controller > versions and should be useful now as well. > We've been using these stats for monitoring and debugging problems after the > fact as these stats can be collected and stored for later use. > > One might argue that most of this information can be exported using blktrace > when debugging. However, blktrace has non-trivial performance impact and > cannot be always turned on. These stats provide a way for continuous monitoring > without losing much performance on rotational disks. We've been able to look > at these stats and debug issues after problems have been reported in the wild > and understand the IO pattern of the affected workloads. > Some of these stats are also a good data source for high-level analysis and > capacity planning. > > This patchset adds 4 stats and I will send out another patchset later for > stats like io_merged and some stats that can be turned on only for > debugging - idle_time (total time spent idling for this blkio_group), > wait_time (total time spent by the blkio_group waiting before any one of its > queues got a timeslice). I've tried to breakdown the stats and sent the most > basic ones here.
Thanks, I think this makes sense. I've applied it for 2.6.35.
-- Jens Axboe
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