mm: hugetlb_vmemmap: cleanup hugetlb_vmemmap related functions

Patch series "cleanup hugetlb_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" is more clear.  In this series, cheanup related codes to
make it more clear and expressive.  This is suggested by David.


This patch (of 3):

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".  And some function names are prefixed with "huge_page"
instead of "hugetlb", it is easily to be confused with THP.  In this
patch, cheanup related functions to make code more clear and expressive.

Link: https://lkml.kernel.org/r/20220404074652.68024-1-songmuchun@bytedance.com
Link: https://lkml.kernel.org/r/20220404074652.68024-2-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 20 insertions, 22 deletions

diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
index 791626983c2e..91b79b9d9e25 100644
--- a/mm/hugetlb_vmemmap.c
+++ b/mm/hugetlb_vmemmap.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * Free some vmemmap pages of HugeTLB
+ * Optimize vmemmap pages associated with HugeTLB
  *
  * Copyright (c) 2020, Bytedance. All rights reserved.
  *
@@ -192,7 +192,7 @@ DEFINE_STATIC_KEY_MAYBE(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON,
 			hugetlb_free_vmemmap_enabled_key);
 EXPORT_SYMBOL(hugetlb_free_vmemmap_enabled_key);
 
-static int __init early_hugetlb_free_vmemmap_param(char *buf)
+static int __init hugetlb_vmemmap_early_param(char *buf)
 {
 	/* We cannot optimize if a "struct page" crosses page boundaries. */
 	if (!is_power_of_2(sizeof(struct page))) {
@@ -212,29 +212,26 @@ static int __init early_hugetlb_free_vmemmap_param(char *buf)
 
 	return 0;
 }
-early_param("hugetlb_free_vmemmap", early_hugetlb_free_vmemmap_param);
-
-static inline unsigned long free_vmemmap_pages_size_per_hpage(struct hstate *h)
-{
-	return (unsigned long)free_vmemmap_pages_per_hpage(h) << PAGE_SHIFT;
-}
+early_param("hugetlb_free_vmemmap", hugetlb_vmemmap_early_param);
 
 /*
  * Previously discarded vmemmap pages will be allocated and remapping
  * after this function returns zero.
  */
-int alloc_huge_page_vmemmap(struct hstate *h, struct page *head)
+int hugetlb_vmemmap_alloc(struct hstate *h, struct page *head)
 {
 	int ret;
 	unsigned long vmemmap_addr = (unsigned long)head;
-	unsigned long vmemmap_end, vmemmap_reuse;
+	unsigned long vmemmap_end, vmemmap_reuse, vmemmap_pages;
 
 	if (!HPageVmemmapOptimized(head))
 		return 0;
 
-	vmemmap_addr += RESERVE_VMEMMAP_SIZE;
-	vmemmap_end = vmemmap_addr + free_vmemmap_pages_size_per_hpage(h);
-	vmemmap_reuse = vmemmap_addr - PAGE_SIZE;
+	vmemmap_addr	+= RESERVE_VMEMMAP_SIZE;
+	vmemmap_pages	= hugetlb_optimize_vmemmap_pages(h);
+	vmemmap_end	= vmemmap_addr + (vmemmap_pages << PAGE_SHIFT);
+	vmemmap_reuse	= vmemmap_addr - PAGE_SIZE;
+
 	/*
 	 * The pages which the vmemmap virtual address range [@vmemmap_addr,
 	 * @vmemmap_end) are mapped to are freed to the buddy allocator, and
@@ -250,17 +247,18 @@ int alloc_huge_page_vmemmap(struct hstate *h, struct page *head)
 	return ret;
 }
 
-void free_huge_page_vmemmap(struct hstate *h, struct page *head)
+void hugetlb_vmemmap_free(struct hstate *h, struct page *head)
 {
 	unsigned long vmemmap_addr = (unsigned long)head;
-	unsigned long vmemmap_end, vmemmap_reuse;
+	unsigned long vmemmap_end, vmemmap_reuse, vmemmap_pages;
 
-	if (!free_vmemmap_pages_per_hpage(h))
+	vmemmap_pages = hugetlb_optimize_vmemmap_pages(h);
+	if (!vmemmap_pages)
 		return;
 
-	vmemmap_addr += RESERVE_VMEMMAP_SIZE;
-	vmemmap_end = vmemmap_addr + free_vmemmap_pages_size_per_hpage(h);
-	vmemmap_reuse = vmemmap_addr - PAGE_SIZE;
+	vmemmap_addr	+= RESERVE_VMEMMAP_SIZE;
+	vmemmap_end	= vmemmap_addr + (vmemmap_pages << PAGE_SHIFT);
+	vmemmap_reuse	= vmemmap_addr - PAGE_SIZE;
 
 	/*
 	 * Remap the vmemmap virtual address range [@vmemmap_addr, @vmemmap_end)
@@ -297,8 +295,8 @@ void __init hugetlb_vmemmap_init(struct hstate *h)
 	 * hugetlbpage.rst for more details.
 	 */
 	if (likely(vmemmap_pages > RESERVE_VMEMMAP_NR))
-		h->nr_free_vmemmap_pages = vmemmap_pages - RESERVE_VMEMMAP_NR;
+		h->optimize_vmemmap_pages = vmemmap_pages - RESERVE_VMEMMAP_NR;
 
-	pr_info("can free %d vmemmap pages for %s\n", h->nr_free_vmemmap_pages,
-		h->name);
+	pr_info("can optimize %d vmemmap pages for %s\n",
+		h->optimize_vmemmap_pages, h->name);
 }