Re: [PATCH 1/1] blktrace: fix accounting of partially completed requests

From: Jens Axboe
Date: Wed Mar 05 2014 - 18:10:22 EST


On 03/04/2014 07:13 AM, Roman Pen wrote:
trace_block_rq_complete does not take into account that request can
be partially completed, so we can get the following incorrect output
of blkparser:

C R 232 + 240 [0]
C R 240 + 232 [0]
C R 248 + 224 [0]
C R 256 + 216 [0]

but should be:

C R 232 + 8 [0]
C R 240 + 8 [0]
C R 248 + 8 [0]
C R 256 + 8 [0]

Also, the whole output summary statistics of completed requests and
final throughput will be incorrect.

This patch takes into account real completion size of the request and
fixes wrong completion accounting.

Thanks Roman, this looks good. I'll apply it for 3.15, but with an added stable tag as well.

--
Jens Axboe

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