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Subject: Re: Replacement for page fault notifiers?
From: Pavel Roskin <proski@gnu.org>
To: Matt Mackall <mpm@selenic.com>
Cc: Arjan van de Ven <arjan@infradead.org>,
       Christoph Hellwig <hch@infradead.org>,
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Date: Wed, 09 Jan 2008 21:21:33 -0500
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On Wed, 2008-01-09 at 20:03 -0600, Matt Mackall wrote:

> That makes it way too easy for drivers of questionable legality to just
> clear that bit. Also, we've got a shortage of page bits, etc.

If we ever have this problem, the bit can be changed in the kernel to
fool those drivers (I hope the shortage is not so dire that there will
be no more bits left).

I don't think evil drivers should be a problem per se.  There are
existing non-free drivers that still need to be traced over and over
again.  I guess ndiswrapper could use tracing for Windows drivers that
don't know anything about Linux page flags.

Last but not least, mmiotrace should be useful for free drivers in the
first place to have a legitimate reason to be in the kernel.

-- 
Regards,
Pavel Roskin