Re: [PATCH v5 0/2] io_uring: Add support for napi_busy_poll

Jens Axboe
2022-03-10T13:36:38Z

On 3/8/22 3:17 PM, Olivier Langlois wrote:
> The sqpoll thread can be used for performing the napi busy poll in a
> similar way that it does io polling for file systems supporting direct
> access bypassing the page cache.
>
> The other way that io_uring can be used for napi busy poll is by
> calling io_uring_enter() to get events.
>
> If the user specify a timeout value, it is distributed between polling
> and sleeping by using the systemwide setting
> /proc/sys/net/core/busy_poll.
>
> The changes have been tested with this program:
> https://github.com/lano1106/io_uring_udp_ping
>
> and the result is:
> Without sqpoll:
> NAPI busy loop disabled:
> rtt min/avg/max/mdev = 40.631/42.050/58.667/1.547 us
> NAPI busy loop enabled:
> rtt min/avg/max/mdev = 30.619/31.753/61.433/1.456 us
>
> With sqpoll:
> NAPI busy loop disabled:
> rtt min/avg/max/mdev = 42.087/44.438/59.508/1.533 us
> NAPI busy loop enabled:
> rtt min/avg/max/mdev = 35.779/37.347/52.201/0.924 us

Applied, thanks.

--
Jens Axboe