Date: Tue, 4 Nov 2008 15:36:53 -0700
From: Jonathan Corbet <corbet@lwn.net>
To: Ingo Molnar <mingo@elte.hu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
       Keith Packard <keithp@keithp.com>,
       Jesse Barnes <jbarnes@virtuousgeek.org>,
       Nick Piggin <nickpiggin@yahoo.com.au>, Dave Airlie <airlied@linux.ie>,
       Yinghai Lu <yinghai@kernel.org>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [git pull] IO mappings, #2
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Having looked at this some, I have one, tiny little suggestion:

> +With this mapping object, individual pages can be mapped either
> atomically +or not, depending on the necessary scheduling
> environment. Of course, atomic +maps are more efficient:
> +
> +	void *io_mapping_map_atomic_wc(struct io_mapping *mapping,
> +				       unsigned long offset)

Should the documentation for this function (perhaps the
certainly-forthcoming kerneldoc comments :) mention loudly that this
function uses KM_USER0?  This isn't kmap(), and doesn't look much like
it; someday some developer might get an ugly surprise when they try to
use that slot simultaneously for something else.

jon
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