From 2d30a1f6315b8940537e8e98882c6038fbac9ba5 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 10 Mar 2010 15:20:40 -0800 Subject: mm: do not iterate over NR_CPUS in __zone_pcp_update() __zone_pcp_update() iterates over NR_CPUS instead of limiting the access to the possible cpus. This might result in access to uninitialized areas as the per cpu allocator only populates the per cpu memory for possible cpus. This problem was created as a result of the dynamic allocation of pagesets from percpu memory that went in during the merge window - commit 99dcc3e5a94ed491fbef402831d8c0bbb267f995 ("this_cpu: Page allocator conversion"). Signed-off-by: Thomas Gleixner Acked-by: Pekka Enberg Acked-by: Tejun Heo Acked-by: Christoph Lameter Acked-by: Mel Gorman Reviewed-by: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index a8182c89de59..78ce90dd671f 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3224,7 +3224,7 @@ static int __zone_pcp_update(void *data) int cpu; unsigned long batch = zone_batchsize(zone), flags; - for (cpu = 0; cpu < NR_CPUS; cpu++) { + for_each_possible_cpu(cpu) { struct per_cpu_pageset *pset; struct per_cpu_pages *pcp; -- cgit v1.2.3 From 718a38211bf4375c0a1efad3afbc5dbaef5d33f9 Mon Sep 17 00:00:00 2001 From: Wu Fengguang Date: Wed, 10 Mar 2010 15:20:43 -0800 Subject: mm: introduce dump_page() and print symbolic flag names - introduce dump_page() to print the page info for debugging some error condition. - convert three mm users: bad_page(), print_bad_pte() and memory offline failure. - print an extra field: the symbolic names of page->flags Example dump_page() output: [ 157.521694] page:ffffea0000a7cba8 count:2 mapcount:1 mapping:ffff88001c901791 index:0x147 [ 157.525570] page flags: 0x100000000100068(uptodate|lru|active|swapbacked) Signed-off-by: Wu Fengguang Cc: Ingo Molnar Cc: Alex Chiang Cc: Rik van Riel Cc: Andi Kleen Cc: Mel Gorman Cc: Christoph Lameter Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 79 insertions(+), 4 deletions(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 78ce90dd671f..d03c946d5566 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -50,6 +50,7 @@ #include #include #include +#include #include #include @@ -288,10 +289,7 @@ static void bad_page(struct page *page) printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n", current->comm, page_to_pfn(page)); - printk(KERN_ALERT - "page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n", - page, (void *)page->flags, page_count(page), - page_mapcount(page), page->mapping, page->index); + dump_page(page); dump_stack(); out: @@ -5183,3 +5181,80 @@ bool is_free_buddy_page(struct page *page) return order < MAX_ORDER; } #endif + +static struct trace_print_flags pageflag_names[] = { + {1UL << PG_locked, "locked" }, + {1UL << PG_error, "error" }, + {1UL << PG_referenced, "referenced" }, + {1UL << PG_uptodate, "uptodate" }, + {1UL << PG_dirty, "dirty" }, + {1UL << PG_lru, "lru" }, + {1UL << PG_active, "active" }, + {1UL << PG_slab, "slab" }, + {1UL << PG_owner_priv_1, "owner_priv_1" }, + {1UL << PG_arch_1, "arch_1" }, + {1UL << PG_reserved, "reserved" }, + {1UL << PG_private, "private" }, + {1UL << PG_private_2, "private_2" }, + {1UL << PG_writeback, "writeback" }, +#ifdef CONFIG_PAGEFLAGS_EXTENDED + {1UL << PG_head, "head" }, + {1UL << PG_tail, "tail" }, +#else + {1UL << PG_compound, "compound" }, +#endif + {1UL << PG_swapcache, "swapcache" }, + {1UL << PG_mappedtodisk, "mappedtodisk" }, + {1UL << PG_reclaim, "reclaim" }, + {1UL << PG_buddy, "buddy" }, + {1UL << PG_swapbacked, "swapbacked" }, + {1UL << PG_unevictable, "unevictable" }, +#ifdef CONFIG_MMU + {1UL << PG_mlocked, "mlocked" }, +#endif +#ifdef CONFIG_ARCH_USES_PG_UNCACHED + {1UL << PG_uncached, "uncached" }, +#endif +#ifdef CONFIG_MEMORY_FAILURE + {1UL << PG_hwpoison, "hwpoison" }, +#endif + {-1UL, NULL }, +}; + +static void dump_page_flags(unsigned long flags) +{ + const char *delim = ""; + unsigned long mask; + int i; + + printk(KERN_ALERT "page flags: %#lx(", flags); + + /* remove zone id */ + flags &= (1UL << NR_PAGEFLAGS) - 1; + + for (i = 0; pageflag_names[i].name && flags; i++) { + + mask = pageflag_names[i].mask; + if ((flags & mask) != mask) + continue; + + flags &= ~mask; + printk("%s%s", delim, pageflag_names[i].name); + delim = "|"; + } + + /* check for left over flags */ + if (flags) + printk("%s%#lx", delim, flags); + + printk(")\n"); +} + +void dump_page(struct page *page) +{ + printk(KERN_ALERT + "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n", + page, page_count(page), page_mapcount(page), + page->mapping, page->index); + dump_page_flags(page->flags); +} -- cgit v1.2.3