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Date: Thu, 22 Mar 2012 14:41:22 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>,
        Minchan Kim <minchan@kernel.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
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        Ben Herrenschmidt <benh@kernel.crashing.org>,
        "linux@arm.linux.org.uk" <linux@arm.linux.org.uk>
Subject: Re: [PATCH 00/16] mm: prepare for converting vm->vm_flags to 64-bit
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On Thu, 22 Mar 2012 21:28:11 +0000
Al Viro <viro@ZenIV.linux.org.uk> wrote:

> On Thu, Mar 22, 2012 at 02:26:47PM -0700, Andrew Morton wrote:
> > It would be nice to find some way of triggering compiler warnings or
> > sparse warnings if someone mixes a 32-bit type with a vm_flags_t.  Any
> > thoughts on this?
> > 
> > (Maybe that's what __nocast does, but Documentation/sparse.txt doesn't
> > describe it)
> 
> Use __bitwise for that - check how gfp_t is handled.

So what does __nocast do?