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

On 9/23/22 9:16 AM, Christoph Hellwig wrote:

On Thu, Sep 22, 2022 at 12:28:00PM -0600, Jens Axboe wrote:

quoted

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.

-- 
Jens Axboe