Re: [PATCH] /dev/mem: nowait zero/null ops

From: Greg Kroah-Hartman
Date: Wed Sep 08 2021 - 06:25:43 EST

On Wed, Sep 08, 2021 at 11:06:51AM +0100, Pavel Begunkov wrote:
> Make read_iter_zero() to honor IOCB_NOWAIT, so /dev/zero can be
> advertised as FMODE_NOWAIT. This helps subsystems like io_uring to use
> it more effectively. Set FMODE_NOWAIT for /dev/null as well, it never
> waits and therefore trivially meets the criteria.

I do not understand, why would io_uring need to use /dev/zero and how is
this going to help anything?

What workload does this help with?


greg k-h