Re: move hyperv CHANNELMSG_UNLOAD from crashed kernel to kdump kernel

From: Vitaly Kuznetsov
Date: Thu Dec 15 2016 - 05:54:50 EST

Olaf Hering <olaf@xxxxxxxxx> writes:

> On Thu, Dec 15, Olaf Hering wrote:
>> On Thu, Dec 15, Vitaly Kuznetsov wrote:
>> > I see a number of minor but at least one major issue against such move:
>> > At least for some Hyper-V versions (2012R2 for example)
>> > CHANNELMSG_UNLOAD_RESPONSE is delivered to the CPU which initially sent
>> > CHANNELMSG_REQUESTOFFERS and on kdump we may not have this CPU up as
>> > we usually do kdump with nr_cpus=1 (and on the CPU which crashed).
>> Since the kdump or kexec kernel will send the unload during boot I would
>> expect the response to arrive where it was sent, independent from the
>> number of cpus.
> Wait, I just noticed that "REQUESTOFFERS" now. That might be a reason
> why my suggestion will not work.

Yep, that's what I meant to say.