Re: [PATCH linux-2.6-block.git] Fix blktrace trace ordering for plug branch
From: Jens Axboe
Date: Mon Apr 30 2007 - 02:50:51 EST
On Fri, Apr 27 2007, Alan D. Brunelle wrote:
> The attached patch will correct the ordering of trace output between
> request queue insertions (I) and unplug calls (U). Right now the insert
> precedes the unplug, which just isn't right:
>
> 65,128 0 1 67.699868965 7882 Q R 0 + 1 [aiod]
> 65,128 0 2 67.699876462 7882 G R 0 + 1 [aiod]
> 65,128 0 3 67.699878286 7882 P W [aiod]
> 65,128 0 4 67.699880491 7882 I R 0 + 1 [aiod]
> 65,128 0 5 67.699887589 7882 U R [aiod] 1
> 65,128 0 6 67.699898317 54 D R 0 + 1 [kblockd/0]
> 65,128 2 153 67.700126590 0 C R 0 + 1 [0]
>
> With the patch provided the unplug comes first:
>
> 65,128 3 1 0.000000000 7045 Q R 0 + 1 [aiod]
> 65,128 3 2 0.000002295 7045 G R 0 + 1 [aiod]
> 65,128 3 3 0.000002617 7045 P W [aiod]
> 65,128 3 4 0.000003685 7045 U R [aiod] 1
> 65,128 3 5 0.000004107 7045 I R 0 + 1 [aiod]
> 65,128 3 6 0.000009491 57 D R 0 + 1 [kblockd/3]
> 65,128 2 1 0.000232447 0 C R 0 + 1 [0]
>
> Jens: If you agree, the patch can be applied to your plug branch for
> git://git.kernel.dk/data/git/linux-2.6-block.git
Thanks, with that applied the unplug ordering should be the same after
the plugging changes. Applied.
--
Jens Axboe
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