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Date: Tue, 24 Jan 2012 16:32:47 -0200
From: Marcelo Tosatti <mtosatti@redhat.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Pekka Enberg <penberg@kernel.org>, Rik van Riel <riel@redhat.com>,
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        KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Subject: Re: [RFC 1/3] /dev/low_mem_notify
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On Tue, Jan 24, 2012 at 04:25:55PM +0000, Arnd Bergmann wrote:
> On Tuesday 24 January 2012, Pekka Enberg wrote:
> > On Tue, 2012-01-24 at 13:40 -0200, Marcelo Tosatti wrote:
> > > What is the practical advantage of a syscall, again?
> > 
> > Why do you ask? The advantage for this particular case is not needing to
> > add ioctls() for configuration and keeping the file read/write ABI
> > simple.
> 
> The two are obviously equivalent and there is no reason to avoid
> ioctl in general. However I agree that the syscall would be better
> in this case, because that is what we tend to use for core kernel
> functionality, while character devices tend to be used for I/O device
> drivers that need stuff like enumeration and permission management.
> 
> 	Arnd

Makes sense.