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Date:   Wed, 8 Sep 2021 12:25:36 +0200
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Pavel Begunkov <asml.silence@gmail.com>
Cc:     Arnd Bergmann <arnd@arndb.de>, linux-kernel@vger.kernel.org,
        Jens Axboe <axboe@kernel.dk>, io-uring@vger.kernel.org
Subject: Re: [PATCH] /dev/mem: nowait zero/null ops
Message-ID: <YTiPoKc9GiG52DNd@kroah.com>
References: <16c78d25f507b571df7eb852a571141a0fdc73fd.1631095567.git.asml.silence@gmail.com>
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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?

thanks,

greg k-h