[PATCH v4 4/5] arm64: Enable ARCH_HAS_NONLEAF_PMD_YOUNG

[Catalin Marinas]

On Sat, Nov 02, 2024 at 06:42:34PM +0800, Yicong Yang wrote:
> From: Yicong Yang <yangyicong at hisilicon.com>
> 
> With the support of FEAT_HAFT, the NONLEAF_PMD_YOUNG can be enabled
> on arm64 since the hardware is capable of updating the AF flag for
> PMD table descriptor. Since the AF bit of the table descriptor
> shares the same bit position in block descriptors, we only need
> to implement arch_has_hw_nonleaf_pmd_young() and select related
> configs. The related pmd_young test/update operations keeps the
> same with and already implemented for transparent page support.
> 
> Currently ARCH_HAS_NONLEAF_PMD_YOUNG is used to improve the
> efficiency of lru-gen aging.
> 
> Signed-off-by: Yicong Yang <yangyicong at hisilicon.com>

Reviewed-by: Catalin Marinas <catalin.marinas at arm.com>