On 9/27/23 09:13, Stanislav Kinsburskii wrote:
> Once deposited, these pages can't be accessed by Linux anymore and thus
> must be preserved in "used" state across kexec, as hypervisor state is
> unware of kexec.
If Linux can't access them, they're not RAM any more. I'd much rather
remove them from the memory map and move on with life rather than
implement a bunch of new ABI that's got to be handed across kernels.
On 28.09.23 15:22, Dave Hansen wrote:
> On 9/27/23 09:13, Stanislav Kinsburskii wrote:
>> Once deposited, these pages can't be accessed by Linux anymore and thus
>> must be preserved in "used" state across kexec, as hypervisor state is
>> unware of kexec.
>
> If Linux can't access them, they're not RAM any more. I'd much rather
> remove them from the memory map and move on with life rather than
> implement a bunch of new ABI that's got to be handed across kernels.
The motivation of handling kexec (faster?) in a hyper-v domain doesn't
sound particularly compelling got me for such features. If you inflated
memory, just don't allow to kexec. It's been broken for years IIUC.
Maybe the other use cases are more "relevant".
--
Cheers,
David / dhildenb
On 9/28/23 10:35, David Hildenbrand wrote:
> On 28.09.23 15:22, Dave Hansen wrote:
>> On 9/27/23 09:13, Stanislav Kinsburskii wrote:
>>> Once deposited, these pages can't be accessed by Linux anymore and thus
>>> must be preserved in "used" state across kexec, as hypervisor state is
>>> unware of kexec.
>>
>> If Linux can't access them, they're not RAM any more. I'd much rather
>> remove them from the memory map and move on with life rather than
>> implement a bunch of new ABI that's got to be handed across kernels.
>
> The motivation of handling kexec (faster?) in a hyper-v domain doesn't
> sound particularly compelling got me for such features. If you inflated
> memory, just don't allow to kexec. It's been broken for years IIUC.
That's a good point. What prevents deflating before kexec?