Re: [PATCH v3] block: fix blk-iolatency accounting underflow

2018-12-17 Thread Liu Bo
On Mon, Dec 17, 2018 at 1:28 PM Dennis Zhou wrote: > > On Mon, Dec 17, 2018 at 11:42:28AM -0800, Liu Bo wrote: > > On Mon, Dec 17, 2018 at 8:04 AM Dennis Zhou wrote: > > > > > > The blk-iolatency controller measures the time from rq_qos_throttle() to > > > rq_qos_done_bio() and attributes this

Re: [PATCH v3] block: fix blk-iolatency accounting underflow

2018-12-17 Thread Dennis Zhou
On Mon, Dec 17, 2018 at 11:42:28AM -0800, Liu Bo wrote: > On Mon, Dec 17, 2018 at 8:04 AM Dennis Zhou wrote: > > > > The blk-iolatency controller measures the time from rq_qos_throttle() to > > rq_qos_done_bio() and attributes this time to the first bio that needs > > to create the request. This

Re: [PATCH v3] block: fix blk-iolatency accounting underflow

2018-12-17 Thread Liu Bo
On Mon, Dec 17, 2018 at 8:04 AM Dennis Zhou wrote: > > The blk-iolatency controller measures the time from rq_qos_throttle() to > rq_qos_done_bio() and attributes this time to the first bio that needs > to create the request. This means if a bio is plug-mergeable or > bio-mergeable, it gets to

Re: [PATCH v3] block: fix blk-iolatency accounting underflow

2018-12-17 Thread Jens Axboe
On 12/17/18 9:03 AM, Dennis Zhou wrote: > The blk-iolatency controller measures the time from rq_qos_throttle() to > rq_qos_done_bio() and attributes this time to the first bio that needs > to create the request. This means if a bio is plug-mergeable or > bio-mergeable, it gets to bypass the

[PATCH v3] block: fix blk-iolatency accounting underflow

2018-12-17 Thread Dennis Zhou
The blk-iolatency controller measures the time from rq_qos_throttle() to rq_qos_done_bio() and attributes this time to the first bio that needs to create the request. This means if a bio is plug-mergeable or bio-mergeable, it gets to bypass the blk-iolatency controller. The recent series [1], to