From 19d6242ece1f35aa004a7da9adf52e0ec18a854e Mon Sep 17 00:00:00 2001 From: Miles Chen Date: Thu, 21 Mar 2019 12:21:25 +0800 Subject: [PATCH] arm64: setup min_low_pfn When debugging with CONFIG_PAGE_OWNER, I noticed that the min_low_pfn on arm64 is always zero and the page owner scanning has to start from zero. We have to loop a while before we see the first valid pfn. (see: read_page_owner()) Setup min_low_pfn to save some loops. Before setting min_low_pfn: [ 21.265602] min_low_pfn=0, *ppos=0 Page allocated via order 0, mask 0x100cca(GFP_HIGHUSER_MOVABLE) PFN 262144 type Movable Block 512 type Movable Flags 0x8001e referenced|uptodate|dirty|lru|swapbacked) prep_new_page+0x13c/0x140 get_page_from_freelist+0x254/0x1068 __alloc_pages_nodemask+0xd4/0xcb8 After setting min_low_pfn: [ 11.025787] min_low_pfn=262144, *ppos=0 Page allocated via order 0, mask 0x100cca(GFP_HIGHUSER_MOVABLE) PFN 262144 type Movable Block 512 type Movable Flags 0x8001e referenced|uptodate|dirty|lru|swapbacked) prep_new_page+0x13c/0x140 get_page_from_freelist+0x254/0x1068 __alloc_pages_nodemask+0xd4/0xcb8 shmem_alloc_page+0x7c/0xa0 shmem_alloc_and_acct_page+0x124/0x1e8 shmem_getpage_gfp.isra.7+0x118/0x878 shmem_write_begin+0x38/0x68 Signed-off-by: Miles Chen Signed-off-by: Will Deacon --- arch/arm64/mm/init.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index c29b17b..43fa756 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -440,6 +440,7 @@ void __init bootmem_init(void) early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT); max_pfn = max_low_pfn = max; + min_low_pfn = min; arm64_numa_init(); /* -- 2.7.4