Re: [PATCH 12/17] nvme: enable bio-cache for fixed-buffer passthru

Kanchan Joshi
2022-03-14T18:19:17Z

On Fri, Mar 11, 2022 at 12:18 PM Christoph Hellwig <hch@lst.de> wrote:
>
> On Tue, Mar 08, 2022 at 08:51:00PM +0530, Kanchan Joshi wrote:
> > Since we do submission/completion in task, we can have this up.
> > Add a bio-set for nvme as we need that for bio-cache.
>
> Well, passthrough I/O should just use kmalloced bios anyway, as there
> is no need for the mempool to start with. Take a look at the existing
> code in blk-map.c.

Yes, the only reason to switch from kmalloc to bio-set was being able
to use bio-cache.
Towards the goal of matching peak perf of io_uring's block io path.
Is it too bad to go down this route; Is there any different way to
enable bio-cache for passthru.

--
Kanchan