From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Jan Beulich" <JBeulich@suse.com>
Subject: Re: page faults on machines with > 4TB memory
Date: Fri, 24 Jul 2015 04:01:17 -0600
Message-ID: <55B2290D02000078000950C1@prv-mh.provo.novell.com>
References: <20150723163556.GA13434@elena.ufimtseva>
	<55B11DF9.4030002@citrix.com>
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To: Andrew Cooper <andrew.cooper3@citrix.com>, xen-devel@lists.xen.org, Elena Ufimtseva <elena.ufimtseva@oracle.com>
Cc: adnan.misherfi@oracle.com
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>>> On 23.07.15 at 19:01, <andrew.cooper3@citrix.com> wrote:
> Observe that ffff8840ffdb53c0 is actually a pointer in the 64bit PV
> virtual region, because the xenheap allocator has wandered off the top
> of the directmap region.  This is a direct result of passing numa node
> information to alloc_xenheap_page(), which overrides the check which
> keeps the allocation inside the directmap region.

Does it? Looking at the code I can't see why it would:
alloc_heap_pages() only ever looks at [zone_lo, zone_hi], regardless
of requested node, and alloc_domheap_pages() determines the zone
range based on the bit width requested by the caller
(alloc_xenheap_pages() in this case, unless its caller has asked for
a smaller address width or xenheap_bits isn't set).

Jan