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

Jens Axboe
2022-09-23T15:19:29Z

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.

--
Jens Axboe