Messages in this thread | | | Date | Fri, 11 Mar 2011 20:12:37 +0100 | From | Jens Axboe <> | Subject | Re: [PATCH] blktrace: Use rq->cmd_flags directly in blk_add_trace_rq. |
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On 2011-03-04 07:15, Tao Ma wrote: > From: Tao Ma <boyu.mt@taobao.com> > > In blk_add_trace_rq, we only chose the minor 2 bits from > request's cmd_flags and did some check for discard. > so most of other flags(e.g, REQ_SYNC) are missing. > > For example, with a sync write after blkparse we get: > 8,16 1 1 0.001776503 7509 A WS 1349632 + 1024 <- (8,17) 1347584 > 8,16 1 2 0.001776813 7509 Q WS 1349632 + 1024 [dd] > 8,16 1 3 0.001780395 7509 G WS 1349632 + 1024 [dd] > 8,16 1 5 0.001783186 7509 I W 1349632 + 1024 [dd] > 8,16 1 11 0.001816987 7509 D W 1349632 + 1024 [dd] > 8,16 0 2 0.006218192 0 C W 1349632 + 1024 [0] > > Since now we have integrated the flags of both bio and request, > it is safe to pass rq->cmd_flags directly to __blk_add_trace. > > With this patch, after a sync write we get: > 8,16 1 1 0.001776900 5425 A WS 1189888 + 1024 <- (8,17) 1187840 > 8,16 1 2 0.001777179 5425 Q WS 1189888 + 1024 [dd] > 8,16 1 3 0.001780797 5425 G WS 1189888 + 1024 [dd] > 8,16 1 5 0.001783402 5425 I WS 1189888 + 1024 [dd] > 8,16 1 11 0.001817468 5425 D WS 1189888 + 1024 [dd] > 8,16 0 2 0.005640709 0 C WS 1189888 + 1024 [0]
Thanks, applied!
-- Jens Axboe
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