mm/page_alloc: remove realsize in free_area_init_core()

Highmem's realsize always equals to freesize, so it is not necessary to
spare a variable to record this.

Link: http://lkml.kernel.org/r/20180413083859.65888-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 22320ea..4fbe211 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6229,18 +6229,18 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat)
 
        for (j = 0; j < MAX_NR_ZONES; j++) {
                struct zone *zone = pgdat->node_zones + j;
-               unsigned long size, realsize, freesize, memmap_pages;
+               unsigned long size, freesize, memmap_pages;
                unsigned long zone_start_pfn = zone->zone_start_pfn;
 
                size = zone->spanned_pages;
-               realsize = freesize = zone->present_pages;
+               freesize = zone->present_pages;
 
                /*
                 * Adjust freesize so that it accounts for how much memory
                 * is used by this zone for memmap. This affects the watermark
                 * and per-cpu initialisations
                 */
-               memmap_pages = calc_memmap_size(size, realsize);
+               memmap_pages = calc_memmap_size(size, freesize);
                if (!is_highmem_idx(j)) {
                        if (freesize >= memmap_pages) {
                                freesize -= memmap_pages;
@@ -6272,7 +6272,7 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat)
                 * when the bootmem allocator frees pages into the buddy system.
                 * And all highmem pages will be managed by the buddy system.
                 */
-               zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
+               zone->managed_pages = freesize;
 #ifdef CONFIG_NUMA
                zone->node = nid;
 #endif