Re: [RFC PATCH 0/2] SKSM: Synchronous Kernel Samepage Merging

[David Hildenbrand <david@redhat.com>]

On 28.02.25 16:10, David Hildenbrand wrote:
> On 28.02.25 15:59, Sean Christopherson wrote:
>> On Fri, Feb 28, 2025, David Hildenbrand wrote:
>>> On 28.02.25 06:17, Linus Torvalds wrote:
>>>> On Thu, 27 Feb 2025 at 19:03, Mathieu Desnoyers
>>>> <mathieu.desnoyers@efficios.com> wrote:
>>>>>
>>>>> I'd be fine with SKSM replacing KSM entirely. However, I don't
>>>>> think we should try to re-implement the existing KSM userspace ABIs
>>>>> over SKSM.
>>>>
>>>> No, absolutely. The only point (for me) for your new synchronous one
>>>> would be if it replaced the kernel thread async scanning, which would
>>>> make the old user space interface basically pointless.
>>>>
>>>> But I don't actually know who uses KSM right now. My reaction really
>>>> comes from a "it's not nice code in the kernel", not from any actual
>>>> knowledge of the users.
>>>>
>>>> Maybe it works really well in some cloud VM environment, and we're
>>>> stuck with it forever.
>>>
>>> Exactly that; and besides the VM use-case, lately people stated using it in
>>> the context of interpreters (IIRC inside Meta) quite successfully as well.
>>
>> Does Red Hat (or any other KVM supporters) actually recommend using KSM for VMs
>> in cloud environments?
> 
> Private clouds yes, that's where it is most commonly used for. I would
> assume that nobody for

forgot to complete that sentence: "... nobody really should be using 
that in public clouds."

-- 
Cheers,

David / dhildenb