From: Jens Axboe <axboe@kernel.dk>
To: Al Viro <viro@zeniv.linux.org.uk>,
"Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] char/mem: only use {read,write}_iter, not the old {read,write} functions
Date: Fri, 20 May 2022 09:11:39 -0600 [thread overview]
Message-ID: <f35d7a15-0cbf-1663-15af-eae37a90d0ff@kernel.dk> (raw)
In-Reply-To: <YoevH5YFLcBBfsB0@zeniv-ca.linux.org.uk>
On 5/20/22 9:09 AM, Al Viro wrote:
> On Fri, May 20, 2022 at 03:50:30PM +0200, Jason A. Donenfeld wrote:
>> Currently mem.c implements both the {read,write}_iter functions and the
>> {read,write} functions. But with {read,write} going away at some point
>> in the future,
>
> Not likely to happen, unfortunately.
>
>> and most kernel code made to prefer {read,write}_iter,
>> there's no point in keeping around the old code.
>
> Profile and you'll see ;-/
Weren't you working on bits to get us to performance parity there?
What's the status of that?
It really is an unfortunate situation we're currently in with two
methods for either read or write, with one being greatly preferred as we
can pass in non-file associated state (like IOCB_NOWAIT, etc) but the
older variant being a bit faster. It lives us in a bad place, imho.
--
Jens Axboe
next prev parent reply other threads:[~2022-05-20 15:11 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-20 13:50 [PATCH] char/mem: only use {read,write}_iter, not the old {read,write} functions Jason A. Donenfeld
2022-05-20 14:38 ` Jens Axboe
2022-05-20 15:09 ` Al Viro
2022-05-20 15:11 ` Jens Axboe [this message]
2022-05-20 15:32 ` Jens Axboe
2022-05-20 15:44 ` Al Viro
2022-05-20 15:46 ` Jens Axboe
2022-05-21 17:51 ` Al Viro
2022-05-20 15:24 ` Jason A. Donenfeld
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