From ba914f481507a0542a7c8a3fc15d89414bc2ebf3 Mon Sep 17 00:00:00 2001 From: Zhong Hongbo Date: Fri, 12 Dec 2014 16:56:21 -0800 Subject: [PATCH] mm: remove the highmem zones' memmap in the highmem zone Since 01cefaef40c4 ("mm: provide more accurate estimation of pages occupied by memmap") allocate the pages from lowmem for the highmem zones' memmap. So It is not need to reserver the memmap's for the highmem. A 2G DDR3 for the arm platform: On node 0 totalpages: 524288 free_area_init_node: node 0, pgdat 80ccd380, node_mem_map 80d38000 DMA zone: 3568 pages used for memmap DMA zone: 0 pages reserved DMA zone: 456704 pages, LIFO batch:31 HighMem zone: 528 pages used for memmap HighMem zone: 67584 pages, LIFO batch:15 On node 0 totalpages: 524288 free_area_init_node: node 0, pgdat 80cd6f40, node_mem_map 80d42000 DMA zone: 3568 pages used for memmap DMA zone: 0 pages reserved DMA zone: 456704 pages, LIFO batch:31 HighMem zone: 67584 pages, LIFO batch:15 Signed-off-by: Hongbo Zhong Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 9d3870862293..fa974d87f60d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4937,16 +4937,18 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat, * and per-cpu initialisations */ memmap_pages = calc_memmap_size(size, realsize); - if (freesize >= memmap_pages) { - freesize -= memmap_pages; - if (memmap_pages) - printk(KERN_DEBUG - " %s zone: %lu pages used for memmap\n", - zone_names[j], memmap_pages); - } else - printk(KERN_WARNING - " %s zone: %lu pages exceeds freesize %lu\n", - zone_names[j], memmap_pages, freesize); + if (!is_highmem_idx(j)) { + if (freesize >= memmap_pages) { + freesize -= memmap_pages; + if (memmap_pages) + printk(KERN_DEBUG + " %s zone: %lu pages used for memmap\n", + zone_names[j], memmap_pages); + } else + printk(KERN_WARNING + " %s zone: %lu pages exceeds freesize %lu\n", + zone_names[j], memmap_pages, freesize); + } /* Account for reserved pages */ if (j == 0 && freesize > dma_reserve) { -- 2.34.1