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SubjectRe: [PATCH] blktrace: Use rq->cmd_flags directly in blk_add_trace_rq.
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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