Re: [PATCH 1/6] mm: hugetlb_vmemmap: delete hugetlb_optimize_vmemmap_enabled()

From: Catalin Marinas
Date: Mon Jun 20 2022 - 12:57:29 EST


On Mon, Jun 13, 2022 at 02:35:07PM +0800, Muchun Song wrote:
> The name hugetlb_optimize_vmemmap_enabled() a bit confusing as it tests
> two conditions (enabled and pages in use). Instead of coming up to
> an appropriate name, we could just delete it. There is already a
> discussion about deleting it in thread [1].
>
> There is only one user of hugetlb_optimize_vmemmap_enabled() outside of
> hugetlb_vmemmap, that is flush_dcache_page() in arch/arm64/mm/flush.c.
> However, it does not need to call hugetlb_optimize_vmemmap_enabled()
> in flush_dcache_page() since HugeTLB pages are always fully mapped and
> only head page will be set PG_dcache_clean meaning only head page's flag
> may need to be cleared (see commit cf5a501d985b). So it is easy to
> remove hugetlb_optimize_vmemmap_enabled().
>
> Link: https://lore.kernel.org/all/c77c61c8-8a5a-87e8-db89-d04d8aaab4cc@xxxxxxxxxx/ [1]
> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Will Deacon <will@xxxxxxxxxx>
> Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>

Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>