[GEDI] [PATCH v5 11/12] blkio: implement BDRV_REQ_REGISTERED_BUF optimization

[Alberto Faria]

On Thu, Oct 6, 2022 at 7:00 PM Stefan Hajnoczi <stefanha at redhat.com> wrote:
> s->needs_mem_regions determines if we'll use libblkio memory regions at
> all. When it's false we skip blkio_map_mem_region() and therefore it's
> safe to set s->mem_regions_pinned to false.

blkio_register_buf() calls blkio_map_mem_region(). Is the
bdrv_register_buf callback maybe skipped somehow when
needs_mem_regions is false?

Regardless, I'd say we want to map memory regions even if we don't
strictly need to (in cases where we can do so at no additional cost),
since that may improve performance for some drivers.

Alberto