On 6/6/19 12:29 PM, Christoph Hellwig wrote:
> We only need the number of segments in the blk-mq submission path.
> Remove the field from struct bio, and return it from a variant of
> blk_queue_split instead of that it can passed as an argument to
> those functions that need the value.
>
> This also means we stop recounting segments except for cloning
> and partial segments.
>
> To keep the number of arguments in this how path down remove
> pointless struct request_queue arguments from any of the functions
> that had it and grew a nr_segs argument.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> Documentation/block/biodoc.txt | 1 -
> block/bfq-iosched.c | 5 ++-
> block/bio.c | 15 +------
> block/blk-core.c | 32 +++++++--------
> block/blk-map.c | 10 ++++-
> block/blk-merge.c | 75 ++++++++++++----------------------
> block/blk-mq-sched.c | 26 +++++++-----
> block/blk-mq-sched.h | 10 +++--
> block/blk-mq.c | 23 ++++++-----
> block/blk.h | 23 ++++++-----
> block/kyber-iosched.c | 5 ++-
> block/mq-deadline.c | 5 ++-
> drivers/md/raid5.c | 1 -
> include/linux/bio.h | 1 -
> include/linux/blk-mq.h | 2 +-
> include/linux/blk_types.h | 6 ---
> include/linux/blkdev.h | 1 -
> include/linux/elevator.h | 2 +-
> 18 files changed, 106 insertions(+), 137 deletions(-)
>
In general a very good idea, but:
> @@ -304,6 +301,13 @@ void blk_queue_split(struct request_queue *q, struct bio **bio)
> *bio = split;
> }
> }
> +
> +void blk_queue_split(struct request_queue *q, struct bio **bio)
> +{
> + unsigned int nr_segs;
> +
> + __blk_queue_split(q, bio, &nr_segs);
> +}
> EXPORT_SYMBOL(blk_queue_split);
>
That looks a bit weird, and I guess some or other compiler might
complain here about nr_segs being unused.
Can't we modify __blk_queue_split() to accept a NULL argument here?
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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