mm: remove the total_mapcount argument from page_trans_huge_map_swapcount()

Now that we don't report it to the caller of reuse_swap_page(), we don't
need to request it from page_trans_huge_map_swapcount().

Link: https://lkml.kernel.org/r/20211220205943.456187-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 31d13a393cf0f2c3651033fada8152d1defda730..a93f5b5fc8b6870afb520e057f7f0e1f8d38bf7f 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1601,31 +1601,30 @@ static bool page_swapped(struct page *page)
        return false;
 }
 
-static int page_trans_huge_map_swapcount(struct page *page, int *total_mapcount,
+static int page_trans_huge_map_swapcount(struct page *page,
                                         int *total_swapcount)
 {
-       int i, map_swapcount, _total_mapcount, _total_swapcount;
+       int i, map_swapcount, _total_swapcount;
        unsigned long offset = 0;
        struct swap_info_struct *si;
        struct swap_cluster_info *ci = NULL;
        unsigned char *map = NULL;
-       int mapcount, swapcount = 0;
+       int swapcount = 0;
 
        /* hugetlbfs shouldn't call it */
        VM_BUG_ON_PAGE(PageHuge(page), page);
 
        if (!IS_ENABLED(CONFIG_THP_SWAP) || likely(!PageTransCompound(page))) {
-               mapcount = page_trans_huge_mapcount(page, total_mapcount);
                if (PageSwapCache(page))
                        swapcount = page_swapcount(page);
                if (total_swapcount)
                        *total_swapcount = swapcount;
-               return mapcount + swapcount;
+               return swapcount + page_trans_huge_mapcount(page, NULL);
        }
 
        page = compound_head(page);
 
-       _total_mapcount = _total_swapcount = map_swapcount = 0;
+       _total_swapcount = map_swapcount = 0;
        if (PageSwapCache(page)) {
                swp_entry_t entry;
 
@@ -1639,8 +1638,7 @@ static int page_trans_huge_map_swapcount(struct page *page, int *total_mapcount,
        if (map)
                ci = lock_cluster(si, offset);
        for (i = 0; i < HPAGE_PMD_NR; i++) {
-               mapcount = atomic_read(&page[i]._mapcount) + 1;
-               _total_mapcount += mapcount;
+               int mapcount = atomic_read(&page[i]._mapcount) + 1;
                if (map) {
                        swapcount = swap_count(map[offset + i]);
                        _total_swapcount += swapcount;
@@ -1648,19 +1646,14 @@ static int page_trans_huge_map_swapcount(struct page *page, int *total_mapcount,
                map_swapcount = max(map_swapcount, mapcount + swapcount);
        }
        unlock_cluster(ci);
-       if (PageDoubleMap(page)) {
+
+       if (PageDoubleMap(page))
                map_swapcount -= 1;
-               _total_mapcount -= HPAGE_PMD_NR;
-       }
-       mapcount = compound_mapcount(page);
-       map_swapcount += mapcount;
-       _total_mapcount += mapcount;
-       if (total_mapcount)
-               *total_mapcount = _total_mapcount;
+
        if (total_swapcount)
                *total_swapcount = _total_swapcount;
 
-       return map_swapcount;
+       return map_swapcount + compound_mapcount(page);
 }
 
 /*
@@ -1671,13 +1664,12 @@ static int page_trans_huge_map_swapcount(struct page *page, int *total_mapcount,
  */
 bool reuse_swap_page(struct page *page)
 {
-       int count, total_mapcount, total_swapcount;
+       int count, total_swapcount;
 
        VM_BUG_ON_PAGE(!PageLocked(page), page);
        if (unlikely(PageKsm(page)))
                return false;
-       count = page_trans_huge_map_swapcount(page, &total_mapcount,
-                                             &total_swapcount);
+       count = page_trans_huge_map_swapcount(page, &total_swapcount);
        if (count == 1 && PageSwapCache(page) &&
            (likely(!PageTransCompound(page)) ||
             /* The remaining swap count will be freed soon */