Re: [PATCHSET 0/5] Enable alloc caching and batched freeing for passthrough

Christoph Hellwig
2022-09-23T15:21:58Z

On Fri, Sep 23, 2022 at 09:19:15AM -0600, Jens Axboe wrote:
> On 9/23/22 9:16 AM, Christoph Hellwig wrote:
> > On Thu, Sep 22, 2022 at 12:28:00PM -0600, Jens Axboe wrote:
> >> This is good for a 10% improvement for passthrough performance. For
> >> a non-drive limited test case, passthrough IO is now more efficient
> >> than the regular bdev O_DIRECT path.
> >
> > How so? If it ends up faster we are doing something wrong in the
> > normal path as there should be no fundamental difference in the work
> > that is being done.
>
> There's no fundamental difference, but the bdev path is more involved
> than the simple passthrough path.

Well, I guess that means there is some more fat we need to trim
then..