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Date:   Fri, 20 May 2022 17:24:07 +0200
From:   "Jason A. Donenfeld" <Jason@zx2c4.com>
To:     Al Viro <viro@zeniv.linux.org.uk>
Cc:     gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
        Jens Axboe <axboe@kernel.dk>
Subject: Re: [PATCH] char/mem: only use {read,write}_iter, not the old
 {read,write} functions
Message-ID: <Yoeylxfbl9hDI/jE@zx2c4.com>
References: <20220520135030.166831-1-Jason@zx2c4.com>
 <YoevH5YFLcBBfsB0@zeniv-ca.linux.org.uk>
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Hi Al,

On Fri, May 20, 2022 at 03:09:19PM +0000, 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 ;-/

Huh, yea, I lose around 1 GiB/s of perf on my machine sending /dev/zero
into /dev/null.

Jason