From: Jens Axboe <axboe@kernel.dk>
To: Namhyung Kim <namhyung@gmail.com>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/6] block: introduce __bio_endio()
Date: Tue, 30 Aug 2011 13:15:19 -0600 [thread overview]
Message-ID: <4E5D36C7.5020706@kernel.dk> (raw)
In-Reply-To: <1314589660-2918-3-git-send-email-namhyung@gmail.com>
On 2011-08-28 21:47, Namhyung Kim wrote:
> Currently, bio_endio() lacks its completion tracepoint in it,
> so that the bio-based devices - except DM which inserted the
> tracepoint explicitly - cannot send us such an event when using
> blktrace. Adding the tracepoint in the function will fix this.
>
> However, bio_endio() is also used for other ways like some
> nested bio-handling path and request-based devices. Simply
> adding will result in duplicated event for those cases. Thus
> add new __bio_endio() function to do things as before but no
> tracepoint. Similarly, __bio_io_error() helper was added too.
Not crazy about this solution, it seems a little fragile. And it's hard
to know what the difference between bio_endio() and __bio_endio() is
without looking at the code.
I think it would be cleaner to mark a bio as going inflight, so that we
can check this flag on completion. If it's never been in flight, don't
trigger a completion event trace for it.
--
Jens Axboe
next prev parent reply other threads:[~2011-08-30 19:16 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-29 3:47 [PATCH 0/6] blktrace: bio-based device tracing improvement Namhyung Kim
2011-08-29 3:47 ` [PATCH 1/6] block: move trace_block_bio_remap() before blk_partition_remap Namhyung Kim
2011-08-29 3:47 ` [PATCH 2/6] block: introduce __bio_endio() Namhyung Kim
2011-08-30 19:15 ` Jens Axboe [this message]
2011-09-01 1:43 ` Namhyung Kim
2011-08-29 3:47 ` [PATCH 3/6] bounce: convert to __bio_endio() for bounced bio's Namhyung Kim
2011-08-29 3:47 ` Namhyung Kim
2011-08-29 3:47 ` [PATCH 4/6] bio-integrity: convert to __bio_endio() Namhyung Kim
2011-08-29 3:47 ` [PATCH 5/6] Btrfs: " Namhyung Kim
2011-08-29 3:47 ` [PATCH 6/6] dm: get rid of block_bio_complete tracepoint Namhyung Kim
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