[PATCH v3 01/21] mm, huge-page: reorder arguments to process_huge_page()

[Ankur Arora]

Mechanical change to process_huge_page() to pass subpage clear/copy
args via struct subpage_arg * instead of passing an opaque pointer
around.

No change in generated code.

Signed-off-by: Ankur Arora <ankur.a.arora@xxxxxxxxxx>
---
 mm/memory.c | 47 ++++++++++++++++++++++++++---------------------
 1 file changed, 26 insertions(+), 21 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 21dadf03f089..c33aacdaaf11 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5562,15 +5562,22 @@ EXPORT_SYMBOL(__might_fault);
 #endif
 
 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
+
+struct subpage_arg {
+	struct page *dst;
+	struct page *src;
+	struct vm_area_struct *vma;
+};
+
 /*
  * Process all subpages of the specified huge page with the specified
  * operation.  The target subpage will be processed last to keep its
  * cache lines hot.
  */
-static inline void process_huge_page(
+static inline void process_huge_page(struct subpage_arg *sa,
 	unsigned long addr_hint, unsigned int pages_per_huge_page,
-	void (*process_subpage)(unsigned long addr, int idx, void *arg),
-	void *arg)
+	void (*process_subpage)(struct subpage_arg *sa,
+				unsigned long addr, int idx))
 {
 	int i, n, base, l;
 	unsigned long addr = addr_hint &
@@ -5586,7 +5593,7 @@ static inline void process_huge_page(
 		/* Process subpages at the end of huge page */
 		for (i = pages_per_huge_page - 1; i >= 2 * n; i--) {
 			cond_resched();
-			process_subpage(addr + i * PAGE_SIZE, i, arg);
+			process_subpage(sa, addr + i * PAGE_SIZE, i);
 		}
 	} else {
 		/* If target subpage in second half of huge page */
@@ -5595,7 +5602,7 @@ static inline void process_huge_page(
 		/* Process subpages at the begin of huge page */
 		for (i = 0; i < base; i++) {
 			cond_resched();
-			process_subpage(addr + i * PAGE_SIZE, i, arg);
+			process_subpage(sa, addr + i * PAGE_SIZE, i);
 		}
 	}
 	/*
@@ -5607,9 +5614,9 @@ static inline void process_huge_page(
 		int right_idx = base + 2 * l - 1 - i;
 
 		cond_resched();
-		process_subpage(addr + left_idx * PAGE_SIZE, left_idx, arg);
+		process_subpage(sa, addr + left_idx * PAGE_SIZE, left_idx);
 		cond_resched();
-		process_subpage(addr + right_idx * PAGE_SIZE, right_idx, arg);
+		process_subpage(sa, addr + right_idx * PAGE_SIZE, right_idx);
 	}
 }
 
@@ -5628,9 +5635,9 @@ static void clear_gigantic_page(struct page *page,
 	}
 }
 
-static void clear_subpage(unsigned long addr, int idx, void *arg)
+static void clear_subpage(struct subpage_arg *sa, unsigned long addr, int idx)
 {
-	struct page *page = arg;
+	struct page *page = sa->dst;
 
 	clear_user_highpage(page + idx, addr);
 }
@@ -5640,13 +5647,18 @@ void clear_huge_page(struct page *page,
 {
 	unsigned long addr = addr_hint &
 		~(((unsigned long)pages_per_huge_page << PAGE_SHIFT) - 1);
+	struct subpage_arg sa = {
+		.dst = page,
+		.src = NULL,
+		.vma = NULL,
+	};
 
 	if (unlikely(pages_per_huge_page > MAX_ORDER_NR_PAGES)) {
 		clear_gigantic_page(page, addr, pages_per_huge_page);
 		return;
 	}
 
-	process_huge_page(addr_hint, pages_per_huge_page, clear_subpage, page);
+	process_huge_page(&sa, addr_hint, pages_per_huge_page, clear_subpage);
 }
 
 static void copy_user_gigantic_page(struct page *dst, struct page *src,
@@ -5668,16 +5680,9 @@ static void copy_user_gigantic_page(struct page *dst, struct page *src,
 	}
 }
 
-struct copy_subpage_arg {
-	struct page *dst;
-	struct page *src;
-	struct vm_area_struct *vma;
-};
-
-static void copy_subpage(unsigned long addr, int idx, void *arg)
+static void copy_subpage(struct subpage_arg *copy_arg,
+			 unsigned long addr, int idx)
 {
-	struct copy_subpage_arg *copy_arg = arg;
-
 	copy_user_highpage(copy_arg->dst + idx, copy_arg->src + idx,
 			   addr, copy_arg->vma);
 }
@@ -5688,7 +5693,7 @@ void copy_user_huge_page(struct page *dst, struct page *src,
 {
 	unsigned long addr = addr_hint &
 		~(((unsigned long)pages_per_huge_page << PAGE_SHIFT) - 1);
-	struct copy_subpage_arg arg = {
+	struct subpage_arg sa = {
 		.dst = dst,
 		.src = src,
 		.vma = vma,
@@ -5700,7 +5705,7 @@ void copy_user_huge_page(struct page *dst, struct page *src,
 		return;
 	}
 
-	process_huge_page(addr_hint, pages_per_huge_page, copy_subpage, &arg);
+	process_huge_page(&sa, addr_hint, pages_per_huge_page, copy_subpage);
 }
 
 long copy_huge_page_from_user(struct page *dst_page,
-- 
2.31.1