Re: [RFC PATCH 2/7] block: don't merge different kinds of P2P transfers in a single bio
From: Logan Gunthorpe
Date: Mon Oct 28 2024 - 14:28:34 EST
On 2024-10-27 08:21, Leon Romanovsky wrote:
> From: Christoph Hellwig <hch@xxxxxx>
>
> 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@xxxxxx>
> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
Looks good to me.
Reviewed-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>