From 6b208e3f6e35aa76d254c395bdcd984b17c6b626 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Thu, 12 Jan 2012 17:18:18 -0800 Subject: [PATCH] mm: memcg: remove unused node/section info from pc->flags To find the page corresponding to a certain page_cgroup, the pc->flags encoded the node or section ID with the base array to compare the pc pointer to. Now that the per-memory cgroup LRU lists link page descriptors directly, there is no longer any code that knows the struct page_cgroup of a PFN but not the struct page. [hughd@google.com: remove unused node/section info from pc->flags fix] Signed-off-by: Johannes Weiner Reviewed-by: KAMEZAWA Hiroyuki Reviewed-by: Michal Hocko Reviewed-by: Kirill A. Shutemov Cc: KAMEZAWA Hiroyuki Cc: Michal Hocko Cc: "Kirill A. Shutemov" Cc: Daisuke Nishimura Cc: Balbir Singh Cc: Ying Han Cc: Greg Thelen Cc: Michel Lespinasse Cc: Rik van Riel Cc: Minchan Kim Cc: Christoph Hellwig Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/page_cgroup.h | 33 --------------------- mm/page_cgroup.c | 59 +++++-------------------------------- 2 files changed, 7 insertions(+), 85 deletions(-) diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h index 5bae7535c202..aaa60da8783c 100644 --- a/include/linux/page_cgroup.h +++ b/include/linux/page_cgroup.h @@ -121,39 +121,6 @@ static inline void move_unlock_page_cgroup(struct page_cgroup *pc, local_irq_restore(*flags); } -#ifdef CONFIG_SPARSEMEM -#define PCG_ARRAYID_WIDTH SECTIONS_SHIFT -#else -#define PCG_ARRAYID_WIDTH NODES_SHIFT -#endif - -#if (PCG_ARRAYID_WIDTH > BITS_PER_LONG - NR_PCG_FLAGS) -#error Not enough space left in pc->flags to store page_cgroup array IDs -#endif - -/* pc->flags: ARRAY-ID | FLAGS */ - -#define PCG_ARRAYID_MASK ((1UL << PCG_ARRAYID_WIDTH) - 1) - -#define PCG_ARRAYID_OFFSET (BITS_PER_LONG - PCG_ARRAYID_WIDTH) -/* - * Zero the shift count for non-existent fields, to prevent compiler - * warnings and ensure references are optimized away. - */ -#define PCG_ARRAYID_SHIFT (PCG_ARRAYID_OFFSET * (PCG_ARRAYID_WIDTH != 0)) - -static inline void set_page_cgroup_array_id(struct page_cgroup *pc, - unsigned long id) -{ - pc->flags &= ~(PCG_ARRAYID_MASK << PCG_ARRAYID_SHIFT); - pc->flags |= (id & PCG_ARRAYID_MASK) << PCG_ARRAYID_SHIFT; -} - -static inline unsigned long page_cgroup_array_id(struct page_cgroup *pc) -{ - return (pc->flags >> PCG_ARRAYID_SHIFT) & PCG_ARRAYID_MASK; -} - #else /* CONFIG_CGROUP_MEM_RES_CTLR */ struct page_cgroup; diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c index f59405a8d752..f0559e049e00 100644 --- a/mm/page_cgroup.c +++ b/mm/page_cgroup.c @@ -11,12 +11,6 @@ #include #include -static void __meminit init_page_cgroup(struct page_cgroup *pc, unsigned long id) -{ - pc->flags = 0; - set_page_cgroup_array_id(pc, id); - pc->mem_cgroup = NULL; -} static unsigned long total_usage; #if !defined(CONFIG_SPARSEMEM) @@ -41,28 +35,13 @@ struct page_cgroup *lookup_page_cgroup(struct page *page) return base + offset; } -struct page *lookup_cgroup_page(struct page_cgroup *pc) -{ - unsigned long pfn; - struct page *page; - pg_data_t *pgdat; - - pgdat = NODE_DATA(page_cgroup_array_id(pc)); - pfn = pc - pgdat->node_page_cgroup + pgdat->node_start_pfn; - page = pfn_to_page(pfn); - VM_BUG_ON(pc != lookup_page_cgroup(page)); - return page; -} - static int __init alloc_node_page_cgroup(int nid) { - struct page_cgroup *base, *pc; + struct page_cgroup *base; unsigned long table_size; - unsigned long start_pfn, nr_pages, index; + unsigned long nr_pages; - start_pfn = NODE_DATA(nid)->node_start_pfn; nr_pages = NODE_DATA(nid)->node_spanned_pages; - if (!nr_pages) return 0; @@ -72,10 +51,6 @@ static int __init alloc_node_page_cgroup(int nid) table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS)); if (!base) return -ENOMEM; - for (index = 0; index < nr_pages; index++) { - pc = base + index; - init_page_cgroup(pc, nid); - } NODE_DATA(nid)->node_page_cgroup = base; total_usage += table_size; return 0; @@ -116,23 +91,10 @@ struct page_cgroup *lookup_page_cgroup(struct page *page) return section->page_cgroup + pfn; } -struct page *lookup_cgroup_page(struct page_cgroup *pc) -{ - struct mem_section *section; - struct page *page; - unsigned long nr; - - nr = page_cgroup_array_id(pc); - section = __nr_to_section(nr); - page = pfn_to_page(pc - section->page_cgroup); - VM_BUG_ON(pc != lookup_page_cgroup(page)); - return page; -} - static void *__meminit alloc_page_cgroup(size_t size, int nid) { + gfp_t flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN; void *addr = NULL; - gfp_t flags = GFP_KERNEL | __GFP_NOWARN; addr = alloc_pages_exact_nid(nid, size, flags); if (addr) { @@ -141,9 +103,9 @@ static void *__meminit alloc_page_cgroup(size_t size, int nid) } if (node_state(nid, N_HIGH_MEMORY)) - addr = vmalloc_node(size, nid); + addr = vzalloc_node(size, nid); else - addr = vmalloc(size); + addr = vzalloc(size); return addr; } @@ -166,14 +128,11 @@ static void free_page_cgroup(void *addr) static int __meminit init_section_page_cgroup(unsigned long pfn, int nid) { - struct page_cgroup *base, *pc; struct mem_section *section; + struct page_cgroup *base; unsigned long table_size; - unsigned long nr; - int index; - nr = pfn_to_section_nr(pfn); - section = __nr_to_section(nr); + section = __pfn_to_section(pfn); if (section->page_cgroup) return 0; @@ -193,10 +152,6 @@ static int __meminit init_section_page_cgroup(unsigned long pfn, int nid) return -ENOMEM; } - for (index = 0; index < PAGES_PER_SECTION; index++) { - pc = base + index; - init_page_cgroup(pc, nr); - } /* * The passed "pfn" may not be aligned to SECTION. For the calculation * we need to apply a mask. -- 2.30.2