Re: [dm-devel] [PATCH for-3.3/core] block: add missing block_bio_complete() tracepoint

[Namhyung Kim <namhyung gmail com>]

Hi,

2012-02-17, 13:19 -0800, Tejun Heo:
> bio completion didn't kick block_bio_complete TP.  Only dm was
> explicitly triggering the TP on IO completion.  This makes
> block_bio_complete TP useless for tracers which want to know about
> bios, and all other bio based drivers skip generating blktrace
> completion events.
> 
> This patch makes all bio completions via bio_endio() generate
> block_bio_complete TP.
> 
> * Explicit trace_block_bio_complete() invocation removed from dm and
>   the trace point is unexported.
> 
> * @rq dropped from trace_block_bio_complete().  bios may fly around
>   w/o queue associated.  Verifying and accessing the assocaited queue
>   belongs to TP probes.
> 
> * blktrace now gets both request and bio completions.  Make it ignore
>   bio completions if request completion path is happening.
> 
> This makes all bio based drivers generate blktrace completion events
> properly and makes the block_bio_complete TP actually useful.
> 
> Signed-off-by: Tejun Heo <tj kernel org>
> Original-patch-by: Namhyung Kim <namhyung gmail com>
> Cc: Tejun Heo <tj kernel org>
> Cc: Steven Rostedt <rostedt goodmis org>
> Cc: dm-devel redhat com

Looks better to me, thanks. :)


-- 
Regards,
Namhyung Kim