Re: [PATCH v12 0/3] bio: control bio max size

Can Guo
2021-06-04T06:42:00Z

On 2021-06-04 13:03, Changheun Lee wrote:
> bio size can grow up to 4GB after muli-page bvec has been enabled.
> But sometimes large size of bio would lead to inefficient behaviors.
> Control of bio max size will be helpful to improve inefficiency.
>
> blk_queue_max_bio_bytes() is added to enable be set the max_bio_bytes
> in
> each driver layer. And max_bio_bytes sysfs is added to show current
> max_bio_bytes for each request queue.
> bio size can be controlled via max_bio_bytes.
>

This is interesting, and we also noticed it right after multi-page bvec
is enabled since last year. Internally, we had a hack to disable it.
But it is good to have a tunable to control it. Thanks for the change.

Reviewed-by: Can Guo <cang@codeaurora.org>

> Changheun Lee (3):
> bio: control bio max size
> blk-sysfs: add max_bio_bytes
> ufs: set max_bio_bytes with queue max sectors
>
> Documentation/ABI/testing/sysfs-block | 10 ++++++++++
> Documentation/block/queue-sysfs.rst | 7 +++++++
> block/bio.c | 17 ++++++++++++++---
> block/blk-settings.c | 19 +++++++++++++++++++
> block/blk-sysfs.c | 7 +++++++
> drivers/scsi/ufs/ufshcd.c | 5 +++++
> include/linux/bio.h | 4 +++-
> include/linux/blkdev.h | 3 +++
> 8 files changed, 68 insertions(+), 4 deletions(-)