[RFC PATCH 07/24] mm/hugetlb: Add freeing unused vmemmap pages support for x86
From: Muchun Song <hidden>
Date: 2020-09-16 00:44:31
Also in:
linux-fsdevel, linux-mm, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
On x86_64 architecture, we use hupe page mapping vmemmap area. We should define VMEMMAP_HPAGE_SHIFT to the correct value to support freeing unused vmemmap pages. Signed-off-by: Muchun Song <redacted> --- arch/x86/include/asm/hugetlb.h | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/arch/x86/include/asm/hugetlb.h b/arch/x86/include/asm/hugetlb.h
index 1721b1aadeb1..f5e882f999cd 100644
--- a/arch/x86/include/asm/hugetlb.h
+++ b/arch/x86/include/asm/hugetlb.h@@ -5,6 +5,11 @@ #include <asm/page.h> #include <asm-generic/hugetlb.h> +#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP +#define VMEMMAP_HPAGE_SHIFT PMD_SHIFT +#define arch_vmemmap_support_huge_mapping() boot_cpu_has(X86_FEATURE_PSE) +#endif + #define hugepages_supported() boot_cpu_has(X86_FEATURE_PSE) #endif /* _ASM_X86_HUGETLB_H */
--
2.20.1