Re: [PATCH RFC v2 14/20] x86: mm: skip pud setup when using generic compile-time folded pagetable

"H. Peter Anvin" <[email protected]> Wed, 22 Jul 2026 13:28:40 -0700

Newsgroups	dev.linux.lists.loongarch,org.infradead.lists.kvm-riscv,org.infradead.lists.linux-riscv,org.kernel.vger.kvm,org.kernel.vger.linux-arch,org.kernel.vger.linux-kernel,org.kernel.vger.linux-mips,org.kernel.vger.linux-openrisc,org.kvack.linux-mm
Message-ID	<[email protected]>

On July 22, 2026 1:22:04 PM PDT, Dave Hansen <[email protected]> wrote:
>On 7/22/26 13:18, Yeoreum Yun wrote:
>> Sorry. But do you mean check with cpu_feature_enabled() not with
>> boot_cpu_has()?
>> IIRC, the boot_cpu_has() doesn't use the DISABLE_MASK_BIT_SET() but
>> uses REQUIRED_MASK_BIT_SET() and I don't expect it wouldn't make
>> an optimisation to constant check which is contrast to DISABLE_MASK_BIT_SET().
>
>Ahh, yes. I forgot about that nuance! Moving to cpu_feature_enabled()
>would be great!

It is supposed to. That's the point of the required mask.