lkml.org 
[lkml]   [2011]   [Dec]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
SubjectRe: [PATCH] block: warn the wrong tag only if it is greater than real_max_depth.
From
[ adding original bug reporters ]

On Tue, Dec 20, 2011 at 7:58 AM, Tao Ma <tm@tao.ma> wrote:
> From: Tao Ma <boyu.mt@taobao.com>
>
> In queue depth decreases, we could meet with a tag greater than max_depth,
> but it should never be greater than real_max_depth. So only WARN if
> it is greater than real_max_depth and let it complets if it is greater
> than max_depth.
>
> Reported-by: Dan Williams <dan.j.williams@intel.com>
> Cc: Jens Axboe <axboe@kernel.dk>
> Signed-off-by: Tao Ma <boyu.mt@taobao.com>
> ---
>  block/blk-tag.c |    8 ++++----
>  1 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/block/blk-tag.c b/block/blk-tag.c
> index e74d6d1..1c50d34 100644
> --- a/block/blk-tag.c
> +++ b/block/blk-tag.c
> @@ -286,12 +286,12 @@ void blk_queue_end_tag(struct request_queue *q, struct request *rq)
>
>        BUG_ON(tag == -1);
>
> -       if (unlikely(tag >= bqt->max_depth)) {
> +       if (unlikely(tag >= bqt->real_max_depth)) {
>                /*
> -                * This can happen after tag depth has been reduced.
> -                * But tag shouldn't be larger than real_max_depth.
> +                * tag shouldn't be larger than real_max_depth.
>                 */
> -               WARN_ON(tag >= bqt->real_max_depth);
> +               WARN(1, "tag %d, bqt->real_max_depth %d\n",
> +                    tag, bqt->real_max_depth);
>                return;
>        }

You can use the WARN macro in the if() statement, and maybe it should
only trigger once??

diff --git a/block/blk-tag.c b/block/blk-tag.c
index 918d82c..19cdde4 100644
--- a/block/blk-tag.c
+++ b/block/blk-tag.c
@@ -291,12 +291,13 @@ void blk_queue_end_tag(struct request_queue *q,
struct request *rq)

BUG_ON(tag == -1);

- if (unlikely(tag >= bqt->max_depth)) {
+ if (WARN_ONCE(tag >= bqt->real_max_depth,
+ "%s: tag %d greater than tag map size: %d\n",
+ __func__, tag, bqt->real_max_depth)) {
/*
* This can happen after tag depth has been reduced.
* But tag shouldn't be larger than real_max_depth.
*/
- WARN_ON(tag >= bqt->real_max_depth);
return;
}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2011-12-20 18:33    [W:0.060 / U:0.640 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site