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Subject: Re: [PATCH 1/3] powerpc: mm: make _PAGE_NUMA take effect
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Liu ping fan <kernelfans@gmail.com>
Date: Wed, 11 Dec 2013 20:50:16 +1100
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Cc: linuxppc-dev@lists.ozlabs.org, Paul Mackerras <paulus@samba.org>,
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On Wed, 2013-12-11 at 16:50 +0800, Liu ping fan wrote:
> > why ? , All the hash routines do check for _PAGE_PRESENT via access
> > variable.
> >
> Going through __hash_page_4K(4k on 4k HW), I do not find such check.
> Am I wrong? Or I will send out a patch to fix that.

We pass a bitmask of flags to check which are tested by doing an "andc"
of the PTE on that mask and checking if anything is left...

Ben.