Re: [patch 0/7] x86/kvmclock: Remove memblock dependency and further cleanups

From: Pavel Tatashin
Date: Fri Jul 13 2018 - 20:21:34 EST




On 07/13/2018 06:51 PM, Thomas Gleixner wrote:
> On Wed, 11 Jul 2018, Pavel Tatashin wrote:
>
>>> So this still will have some overhead when kvmclock is not in use, but
>>> bringing it down to zero would be a massive trainwreck and even more
>>> indirections.
>>
>> Hi Thomas,
>>
>> In my opinion, having kvmclock page in __initdata for boot cpu, and
>> setup it in init_hypervisor_platform(). Later, switch to memblock
>> allocated memory in x86_init.hyper.guest_late_init() for all CPUs
>> would not be too bad, and might be even use fewer lines of code. In
>> addition, it won't have any overhead when kvm is not used.
>
> Why memblock? This can be switched when the allocator is up and
> running. And you can use the per cpu allocator for that.
>
> I'm not having cycles at the moment to look at that, so feel free to pick
> the series up and enhance it.

OK, I will add your series into my series, and fix all the comments that were raised by the reviewers.

Pavel