mm: hugetlb_vmemmap: introduce ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP

The feature of minimizing overhead of struct page associated with each HugeTLB page is implemented on x86_64, however, the infrastructure of this feature is already there, we could easily enable it for other architectures. Introduce ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP for other architectures to be easily enabled. Just select this config if they want to enable this feature. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Muchun Song <[email protected]> Suggested-by: Andrew Morton <[email protected]> Reviewed-by: Barry Song <[email protected]> Tested-by: Barry Song <[email protected]> Reviewed-by: Anshuman Khandual <[email protected]> Cc: Bodeddula Balasubramaniam <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: David Hildenbrand <[email protected]> Cc: David Rientjes <[email protected]> Cc: Fam Zheng <[email protected]> Cc: James Morse <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Mike Kravetz <[email protected]> Cc: Oscar Salvador <[email protected]> Cc: Will Deacon <[email protected]> Cc: Xiongchun Duan <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
kawasaki · Apr 29, 2022 · 2e4ec02 · 2e4ec02
1 parent 84448c8
commit 2e4ec02
Show file tree

Hide file tree

Showing 2 changed files with 10 additions and 1 deletion.
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
@@ -121,6 +121,7 @@ config X86
 	select ARCH_WANTS_NO_INSTR
 	select ARCH_WANT_GENERAL_HUGETLB
 	select ARCH_WANT_HUGE_PMD_SHARE
+	select ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP	if X86_64
 	select ARCH_WANT_LD_ORPHAN_WARN
 	select ARCH_WANTS_THP_SWAP		if X86_64
 	select ARCH_HAS_PARANOID_L1D_FLUSH

diff --git a/fs/Kconfig b/fs/Kconfig
@@ -245,9 +245,17 @@ config HUGETLBFS
 config HUGETLB_PAGE
 	def_bool HUGETLBFS
 
+#
+# Select this config option from the architecture Kconfig, if it is preferred
+# to enable the feature of minimizing overhead of struct page associated with
+# each HugeTLB page.
+#
+config ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP
+	bool
+
 config HUGETLB_PAGE_FREE_VMEMMAP
 	def_bool HUGETLB_PAGE
-	depends on X86_64
+	depends on ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP
 	depends on SPARSEMEM_VMEMMAP
 
 config HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON