Re: [PATCH] blktrace: add missing probe argument to block_bio_complete

Jeff Moyer
2011-01-07T14:14:24Z

Mathieu Desnoyers <mathieu.desnoyers@efficios.com> writes:

> blktrace.c block bio complete callback needs to gain a new argument to reflect
> the newly added "error" tracepoint argument. This is needed to match the new
> block_bio_complete TRACE_EVENT as of
> commit de983a7bfcb7c020901ca6e2314cf55a4207ab5a.
>
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> CC: Jeff Moyer <jmoyer@redhat.com>
> CC: Steven Rostedt <rostedt@goodmis.org>
> CC: Frederic Weisbecker <fweisbec@gmail.com>
> CC: Ingo Molnar <mingo@elte.hu>
> CC: Thomas Gleixner <tglx@linutronix.de>
> CC: Jens Axboe <axboe@kernel.dk>
> CC: Li Zefan <lizf@cn.fujitsu.com>
> ---
> kernel/trace/blktrace.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> Index: linux-2.6-lttng/kernel/trace/blktrace.c
> ===================================================================
> --- linux-2.6-lttng.orig/kernel/trace/blktrace.c
> +++ linux-2.6-lttng/kernel/trace/blktrace.c
> @@ -785,7 +785,8 @@ static void blk_add_trace_bio_bounce(voi
> }
>
> static void blk_add_trace_bio_complete(void *ignore,
> - struct request_queue *q, struct bio *bio)
> + struct request_queue *q, struct bio *bio,
> + int error)
> {
> blk_add_trace_bio(q, bio, BLK_TA_COMPLETE);
> }

OK, I clearly didn't look closely enough last time. There's no sense
passing this information down if it isn't used (as you said initially).
blk_add_trace_bio sets the error based on whether or not the
BIO_UPTODATE bit is set. So, I think we should instead revert the patch
I sent you (Mathieu), and then completely get rid of the error field in
the TP macros.

Does that make sense to everyone else?

Cheers,
Jeff