Re: [PATCH] x86/NUMA: make init_node_heap() respect Xen heap limit

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 27/08/15 09:37, Jan Beulich wrote:
> On NUMA systems, where we try to use node local memory for the basic
> control structures of the buddy allocator, this special case needs to
> take into consideration a possible address width limit placed on the
> Xen heap. In turn this (but also other, more abstract considerations)
> requires that xenheap_max_mfn() not be called more than once (at most
> we might permit it to be called a second time with a larger value than
> was passed the first time), and be called only before calling
> end_boot_allocator().
>
> While inspecting all the involved code, a couple of off-by-one issues
> were found (and are being corrected here at once):
> - arch_init_memory() cleared one too many page table slots
> - the highmem_start based invocation of xenheap_max_mfn() passed too
>   big a value
> - xenheap_max_mfn() calculated the wrong bit count in edge cases
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>