Re: [Crash-utility] [Xen-devel] [PATCH 1/5] xen: Always calculate max_cpus value
On 13/07/12 14:19, Daniel Kiper wrote:
On Thu, Jul 05, 2012 at 04:56:39PM +0100, Jan Beulich wrote:
>>>> On 05.07.12 at 17:00, Daniel Kiper <daniel.kiper(a)oracle.com>
wrote:
>> max_cpus is not available since 20374 changeset (Miscellaneous data
>> placement adjustments). It was moved to __initdata section. This section
>> is freed after Xen initialization. Assume that max_cpus is always
>> equal to XEN_HYPER_SIZE(cpumask_t) * 8.
> Using nr_cpu_ids, when available, would seem a better fit. And
Hmmm... I could not find such animal in Xen source code.
However, maybe I missed something.
nr_cpu_ids was introduced into xen-unstable with c/s 23982:511d5e65a302
It is not present in 4.1 or earlier.
~Andrew
> I donm't see why, on dumps from old hypervisors, you wouldn't
> want to continue using max_cpus. Oh, wait, I see - you would
> have to be able to tell whether it actually sits in .init.data, which
> might not be strait forward.
Yep, but I will try to improve that once again.
Daniel
--
Andrew Cooper - Dom0 Kernel Engineer, Citrix XenServer
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