Re: [PATCH] block: add split_alignment for request queue

[Ming Lei <ming.lei@redhat.com>]

On Mon, Jun 15, 2020 at 08:24:08PM -0700, harshad shirwadkar wrote:
> After taking a closer look, I don't see chunk_sectors being accounted
> for in the splitting code. If I understand correctly, the implementation
> of chunk_sectors is such that it allows for one big IO to go through.
> In other words, it tries to avoid the splitting code if possible. But,
> it doesn't seem to guarantee that when an IO is split, it will be

Please take a look at blk_max_size_offset() which is called by
get_max_io_size() from blk_bio_segment_split(), which splits
bio into chunk_sectors aligned bio.

Also you may run IO trace on queue with chunk_sectors setup, and check
if the splitted IO request is what you expected.


Thanks, 
Ming