[PATCH 1/2] kexec: add a dummy note for each offline cpu

[Liu ping fan]

On Wed, Dec 14, 2016 at 4:25 PM, Baoquan He <bhe at redhat.com> wrote:
> On 12/14/16 at 04:15pm, Liu ping fan wrote:
>> On Wed, Dec 14, 2016 at 3:40 PM, Baoquan He <bhe at redhat.com> wrote:
>> > On 12/14/16 at 02:11pm, Pingfan Liu wrote:
>> >> kexec-tools always allocates program headers for each possible cpu. This
>> >> incurs zero PT_NOTE for offline cpu. We mark this case so that later,
>> >> the capture kernel can distinguish it from the mistake of allocated
>> >> program header.
>> >> The counterpart of the capture kernel comes in next patch.
>> >
>> > When you execute dmesg on your testing machine and grep nr_cpu_ids,
>> > what's the value of nr_cpu_ids?
>> >
>> nr_cpu_ids=128
>
> And what's the cpu number of in "lscpu" command?

NUMA node1 CPU(s):     0-7

The system booted up with 128 possible cpu and only 8 online.
Also I tested on x86 guest, after bootup with 8 cpus, then  offline 4
of them, the zero PT_NOTE warning buzz too.