Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
Date:   Fri, 20 May 2022 17:46:04 +0200
From:   "Jason A. Donenfeld" <Jason@zx2c4.com>
To:     Jens Axboe <axboe@kernel.dk>
Cc:     Theodore Ts'o <tytso@mit.edu>, Christoph Hellwig <hch@lst.de>,
        LKML <linux-kernel@vger.kernel.org>,
        Al Viro <viro@zeniv.linux.org.uk>
Subject: Re: [PATCH v4 0/3] random: convert to using iters, for Al Viro
Message-ID: <Yoe3vFmqx4Yua0a1@zx2c4.com>
References: <20220520094459.116240-1-Jason@zx2c4.com>
 <Yoey+FOYO69lS5qP@zx2c4.com>
 <bbdeeca7-9c99-e661-6596-f04ea783a30b@kernel.dk>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <bbdeeca7-9c99-e661-6596-f04ea783a30b@kernel.dk>
Precedence: bulk

Hi Jens,

On Fri, May 20, 2022 at 09:34:46AM -0600, Jens Axboe wrote:
> On 5/20/22 9:25 AM, Jason A. Donenfeld wrote:
> > Are we sure we really want to do this and need to do this?
> 
> I'm very sure, otherwise we're just accepting that we're breaking real
> world applications.

Would we really? I always thought splice() and copy_file_range() and
sendfile() were all kind of "special" in that they mostly do not work
for many things, and so all userspaces need fallback code. And the state
of "mostly not working" has always just been the norm. So broken today,
working tomorrow, broken next week would be par for the course? I might
be *super* wrong here, so feel free to say so, but this has been my
general impression.

Anyway, I do like the idea of supporting splice() and sendfile(). The
performance hit is just kind of sad.

Jason