Re: [PATCH v2 0/5] md: use bio_clone_fast()

From: Jens Axboe
Date: Tue Feb 14 2017 - 10:33:23 EST


On 02/14/2017 08:28 AM, Ming Lei wrote:
> Hi,
>
> This patches replaces bio_clone() with bio_fast_clone() in
> bio_clone_mddev() because:
>
> 1) bio_clone_mddev() is used in raid normal I/O and isn't in
> resync I/O path, and all the direct access to bvec table in
> raid happens on resync I/O only except for write behind of raid1.
> Write behind is treated specially, so the replacement is safe.
>
> 2) for write behind, bio_clone() is kept, but this patchset
> introduces bio_clone_bioset_partial() to just clone one specific
> bvecs range instead of whole table. Then write behind is improved
> too.

You can add my reviewed-by to the first patch. Shaohua, I'm fine
with you carrying this in the md tree, that would be the easiest
way forward.

--
Jens Axboe