[PATCH 1/9] block: don't merge different kinds of P2P transfers in a single bio

[Leon Romanovsky]

On Tue, Jun 10, 2025 at 07:06:39AM +0200, Christoph Hellwig wrote:
> To get out of the DMA mapping helpers having to check every segment for
> it's P2P status, ensure that bios either contain P2P transfers or non-P2P
> transfers, and that a P2P bio only contains ranges from a single device.
> 
> This means we do the page zone access in the bio add path where it should
> be still page hot, and will only have do the fairly expensive P2P topology
> lookup once per bio down in the DMA mapping path, and only for already
> marked bios.
> 
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> ---
>  block/bio-integrity.c     |  3 +++
>  block/bio.c               | 20 +++++++++++++-------
>  include/linux/blk_types.h |  2 ++
>  3 files changed, 18 insertions(+), 7 deletions(-)
> 

Thanks,
Reviewed-by: Leon Romanovsky <leonro at nvidia.com>