[PATCH] trace bio queueing trial only when it occurs

[Minchan Kim <minchan.kim@gmail.com>]

It got lost in LKML mail storm.
I resend this.
Wu, Could you review this patch, please?

== CUT_HERE ==

If BIO is discarded or cross over end of device,
BIO queueing trial doesn't occur.

Let's trace it only when it happens.

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
---
 block/blk-core.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 5b59592..1a0cfd5 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1463,8 +1463,6 @@ static inline void __generic_make_request(struct bio *bio)
 		if (old_sector != -1)
 			trace_block_remap(q, bio, old_dev, old_sector);

-		trace_block_bio_queue(q, bio);
-
 		old_sector = bio->bi_sector;
 		old_dev = bio->bi_bdev->bd_dev;

@@ -1477,6 +1475,8 @@ static inline void __generic_make_request(struct bio *bio)
 			goto end_io;
 		}

+		trace_block_bio_queue(q, bio);
+
 		ret = q->make_request_fn(q, bio);
 	} while (ret);

--
1.6.4



-- 
Kind regards,
Minchan Kim