[PATCHv11 18/19] x86/acpi: Add support for CPU offlining for ACPI MADT wakeup method

Tom Lendacky thomas.lendacky at amd.com
Fri Jun 14 07:06:30 PDT 2024


On 6/13/24 09:56, Borislav Petkov wrote:
> On Thu, Jun 13, 2024 at 04:41:00PM +0300, Kirill A. Shutemov wrote:
>> It is easy enough to do. See the patch below.
> 
> Thanks, will have a look.
> 
>> But I am not sure if I can justify it properly. If someone doesn't really
>> need 5-level paging, disabling it at compile-time would save ~34K of
>> kernel code with the configuration.
>>
>> Is it worth saving ~100 lines of code?
> 
> Well, it goes both ways: is it worth saving ~34K kernel text and for that make
> the code a lot less conditional, more readable, contain less ugly ifdeffery,

Won't getting rid of the config option cause 5-level to be used by default 
on all platforms that support it? The no5lvl command line option would 
have to be used to get 4-level paging at that point.

Thanks,
Tom

> ...?
> 



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