mm: hugetlb_vmemmap: cleanup CONFIG_HUGETLB_PAGE_FREE_VMEMMAP*

The word of "free" is not expressive enough to express the feature of
optimizing vmemmap pages associated with each HugeTLB, rename this keywork
to "optimize".  In this patch , cheanup configs to make code more
expressive.

Link: https://lkml.kernel.org/r/20220404074652.68024-4-songmuchun@bytedance.comSigned-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Documentation/admin-guide/kernel-parameters.txt

@@ -1660,7 +1660,7 @@
 			Format: size[KMG]
 
 	hugetlb_free_vmemmap=
-			[KNL] Reguires CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
+			[KNL] Reguires CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
 			enabled.
 			Allows heavy hugetlb users to free up some more
 			memory (7 * PAGE_SIZE for each 2MB hugetlb page).
@@ -1669,7 +1669,7 @@
 			on:  enable the feature
 			off: disable the feature
 
-			Built with CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON=y,
+			Built with CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON=y,
 			the default is on.
 
 			This is not compatible with memory_hotplug.memmap_on_memory.

Documentation/admin-guide/mm/hugetlbpage.rst

@@ -164,7 +164,7 @@ default_hugepagesz
 	will all result in 256 2M huge pages being allocated.  Valid default
 	huge page size is architecture dependent.
 hugetlb_free_vmemmap
-	When CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is set, this enables freeing
+	When CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP is set, this enables optimizing
 	unused vmemmap pages associated with each HugeTLB page.
 
 When multiple huge page sizes are supported, ``/proc/sys/vm/nr_hugepages``

arch/arm64/Kconfig

@@ -97,7 +97,7 @@ config ARM64
 	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
 	select ARCH_WANT_FRAME_POINTERS
 	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
-	select ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP
+	select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
 	select ARCH_WANT_LD_ORPHAN_WARN
 	select ARCH_WANTS_NO_INSTR
 	select ARCH_HAS_UBSAN_SANITIZE_ALL

arch/arm64/mm/flush.c

@@ -78,7 +78,7 @@ void flush_dcache_page(struct page *page)
 	/*
 	 * Only the head page's flags of HugeTLB can be cleared since the tail
 	 * vmemmap pages associated with each HugeTLB page are mapped with
-	 * read-only when CONFIG_HUGETLB_PAGE_FREE_VMEMMAP is enabled (more
+	 * read-only when CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP is enabled (more
 	 * details can refer to vmemmap_remap_pte()).  Although
 	 * __sync_icache_dcache() only set PG_dcache_clean flag on the head
 	 * page struct, there is more than one page struct with PG_dcache_clean

arch/x86/Kconfig

@@ -121,7 +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_HUGETLB_PAGE_OPTIMIZE_VMEMMAP	if X86_64
 	select ARCH_WANT_LD_ORPHAN_WARN
 	select ARCH_WANTS_THP_SWAP		if X86_64
 	select ARCH_HAS_PARANOID_L1D_FLUSH

arch/x86/mm/init_64.c

@@ -1269,7 +1269,7 @@ static struct kcore_list kcore_vsyscall;
 
 static void __init register_page_bootmem_info(void)
 {
-#if defined(CONFIG_NUMA) || defined(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP)
+#if defined(CONFIG_NUMA) || defined(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP)
 	int i;
 
 	for_each_online_node(i)

fs/Kconfig

@@ -250,22 +250,22 @@ config HUGETLB_PAGE
 # to enable the feature of minimizing overhead of struct page associated with
 # each HugeTLB page.
 #
-config ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP
+config ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
 	bool
 
-config HUGETLB_PAGE_FREE_VMEMMAP
+config HUGETLB_PAGE_OPTIMIZE_VMEMMAP
 	def_bool HUGETLB_PAGE
-	depends on ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP
+	depends on ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
 	depends on SPARSEMEM_VMEMMAP
 
-config HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON
-	bool "Default freeing vmemmap pages of HugeTLB to on"
+config HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON
+	bool "Default optimizing vmemmap pages of HugeTLB to on"
 	default n
-	depends on HUGETLB_PAGE_FREE_VMEMMAP
+	depends on HUGETLB_PAGE_OPTIMIZE_VMEMMAP
 	help
-	  When using HUGETLB_PAGE_FREE_VMEMMAP, the freeing unused vmemmap
+	  When using HUGETLB_PAGE_OPTIMIZE_VMEMMAP, the optimizing unused vmemmap
 	  pages associated with each HugeTLB page is default off. Say Y here
-	  to enable freeing vmemmap pages of HugeTLB by default. It can then
+	  to enable optimizing vmemmap pages of HugeTLB by default. It can then
 	  be disabled on the command line via hugetlb_free_vmemmap=off.
 
 config MEMFD_CREATE

include/linux/hugetlb.h

@@ -623,7 +623,7 @@ struct hstate {
 	unsigned int nr_huge_pages_node[MAX_NUMNODES];
 	unsigned int free_huge_pages_node[MAX_NUMNODES];
 	unsigned int surplus_huge_pages_node[MAX_NUMNODES];
-#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
+#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
 	unsigned int optimize_vmemmap_pages;
 #endif
 #ifdef CONFIG_CGROUP_HUGETLB

include/linux/mm.h

@@ -3145,7 +3145,7 @@ static inline void print_vma_addr(char *prefix, unsigned long rip)
 }
 #endif
 
-#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
+#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
 int vmemmap_remap_free(unsigned long start, unsigned long end,
 		       unsigned long reuse);
 int vmemmap_remap_alloc(unsigned long start, unsigned long end,

include/linux/page-flags.h

@@ -190,13 +190,13 @@ enum pageflags {
 
 #ifndef __GENERATING_BOUNDS_H
 
-#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
-DECLARE_STATIC_KEY_MAYBE(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON,
+#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
+DECLARE_STATIC_KEY_MAYBE(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON,
 			 hugetlb_optimize_vmemmap_key);
 
 static __always_inline bool hugetlb_optimize_vmemmap_enabled(void)
 {
-	return static_branch_maybe(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON,
+	return static_branch_maybe(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON,
 				   &hugetlb_optimize_vmemmap_key);
 }
 

mm/Makefile

@@ -77,7 +77,7 @@ obj-$(CONFIG_FRONTSWAP)	+= frontswap.o
 obj-$(CONFIG_ZSWAP)	+= zswap.o
 obj-$(CONFIG_HAS_DMA)	+= dmapool.o
 obj-$(CONFIG_HUGETLBFS)	+= hugetlb.o
-obj-$(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP)	+= hugetlb_vmemmap.o
+obj-$(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP)	+= hugetlb_vmemmap.o
 obj-$(CONFIG_NUMA) 	+= mempolicy.o
 obj-$(CONFIG_SPARSEMEM)	+= sparse.o
 obj-$(CONFIG_SPARSEMEM_VMEMMAP) += sparse-vmemmap.o

mm/hugetlb_vmemmap.c

@@ -188,7 +188,7 @@
 #define RESERVE_VMEMMAP_NR		1U
 #define RESERVE_VMEMMAP_SIZE		(RESERVE_VMEMMAP_NR << PAGE_SHIFT)
 
-DEFINE_STATIC_KEY_MAYBE(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON,
+DEFINE_STATIC_KEY_MAYBE(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON,
 			hugetlb_optimize_vmemmap_key);
 EXPORT_SYMBOL(hugetlb_optimize_vmemmap_key);
 
@@ -276,7 +276,7 @@ void __init hugetlb_vmemmap_init(struct hstate *h)
 
 	/*
 	 * There are only (RESERVE_VMEMMAP_SIZE / sizeof(struct page)) struct
-	 * page structs that can be used when CONFIG_HUGETLB_PAGE_FREE_VMEMMAP,
+	 * page structs that can be used when CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP,
 	 * so add a BUILD_BUG_ON to catch invalid usage of the tail struct page.
 	 */
 	BUILD_BUG_ON(__NR_USED_SUBPAGE >=

mm/hugetlb_vmemmap.h

@@ -10,7 +10,7 @@
 #define _LINUX_HUGETLB_VMEMMAP_H
 #include <linux/hugetlb.h>
 
-#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
+#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
 int hugetlb_vmemmap_alloc(struct hstate *h, struct page *head);
 void hugetlb_vmemmap_free(struct hstate *h, struct page *head);
 void hugetlb_vmemmap_init(struct hstate *h);
@@ -41,5 +41,5 @@ static inline unsigned int hugetlb_optimize_vmemmap_pages(struct hstate *h)
 {
 	return 0;
 }
-#endif /* CONFIG_HUGETLB_PAGE_FREE_VMEMMAP */
+#endif /* CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP */
 #endif /* _LINUX_HUGETLB_VMEMMAP_H */

mm/sparse-vmemmap.c

@@ -34,7 +34,7 @@
 #include <asm/pgalloc.h>
 #include <asm/tlbflush.h>
 
-#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
+#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
 /**
  * struct vmemmap_remap_walk - walk vmemmap page table
  *
@@ -420,7 +420,7 @@ int vmemmap_remap_alloc(unsigned long start, unsigned long end,
 
 	return 0;
 }
-#endif /* CONFIG_HUGETLB_PAGE_FREE_VMEMMAP */
+#endif /* CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP */
 
 /*
  * Allocate a block of memory to be used to back the virtual memory map