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Subject: Re: [RFC] [PATCH] cache pollution aware __copy_from_user_ll()
From: Arjan van de Ven <arjan@infradead.org>
To: Hiro Yoshioka <hyoshiok@miraclelinux.com>
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Date: Tue, 16 Aug 2005 07:43:35 +0200
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On Tue, 2005-08-16 at 13:54 +0900, Hiro Yoshioka wrote:
> Takahashi san,
> 
> I appreciate your comments.
> 
> > Hi,
> > 
> > BTW, what are you going to do with the page-faults which may happen
> > during __copy_user_zeroing_nocache()? The current process may be blocked
> > in the handler for a while and get FPU registers polluted.
> > kernel_fpu_begin() won't help the case. This is another issue, though.
> 
> My code does nothing do it.
> 
> I need a volunteer to implement it.

it's actually not too hard; all you need is to use SSE and not MMX; and
then just store sse register you're overwriting on the stack or so...