On Tue, Feb 08, 2022 at 01:18:52AM -0700, Yu Zhao wrote: > Some architectures support the accessed bit in non-leaf PMD entries, > e.g., x86 sets the accessed bit in a non-leaf PMD entry when using it > as part of linear address translation [1]. Page table walkers that > clear the accessed bit may use this capability to reduce their search > space. > > Note that: > 1. Although an inline function is preferable, this capability is added > as a configuration option for the consistency with the existing > macros. > 2. Due to the little interest in other varieties, this capability was > only tested on Intel and AMD CPUs. Clarified ARCH_HAS_NONLEAF_PMD_YOUNG for x86 as requested here: https://lore.kernel.org/linux-mm/CAHk-=wgvOqj6LUhNp8V5ddT8eZyYdFDzMZE73KgPggOnc28VWg@xxxxxxxxxxxxxx/ <snipped> > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 9f5bd41bf660..e787b7fc75be 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -85,6 +85,7 @@ config X86 > select ARCH_HAS_PMEM_API if X86_64 > select ARCH_HAS_PTE_DEVMAP if X86_64 > select ARCH_HAS_PTE_SPECIAL > + select ARCH_HAS_NONLEAF_PMD_YOUNG And enabled it for both 32-bit and 64-bit. <snipped>
