From c6a57e19e464db118dc4ab9cfe9e9748c6d630a0 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Sat, 29 Oct 2005 18:16:52 -0700 Subject: [PATCH] [PATCH] memory hotplug prep: fixup bad_range() When doing memory hotplug operations, the size of existing zones can obviously change. This means that zone->zone_{start_pfn,spanned_pages} can change. There are currently no locks that protect these structure members. However, they are rarely accessed at runtime. Outside of swsusp, the only place that I can find is bad_range(). So, split bad_range() up into two pieces: one that needs to be locked and anther that doesn't. Signed-off-by: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 9a2fa8110afc..a51ef94eec33 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -78,21 +78,37 @@ int min_free_kbytes = 1024; unsigned long __initdata nr_kernel_pages; unsigned long __initdata nr_all_pages; -/* - * Temporary debugging check for pages not lying within a given zone. - */ -static int bad_range(struct zone *zone, struct page *page) +static int page_outside_zone_boundaries(struct zone *zone, struct page *page) { if (page_to_pfn(page) >= zone->zone_start_pfn + zone->spanned_pages) return 1; if (page_to_pfn(page) < zone->zone_start_pfn) return 1; + + return 0; +} + +static int page_is_consistent(struct zone *zone, struct page *page) +{ #ifdef CONFIG_HOLES_IN_ZONE if (!pfn_valid(page_to_pfn(page))) - return 1; + return 0; #endif if (zone != page_zone(page)) + return 0; + + return 1; +} +/* + * Temporary debugging check for pages not lying within a given zone. + */ +static int bad_range(struct zone *zone, struct page *page) +{ + if (page_outside_zone_boundaries(zone, page)) return 1; + if (!page_is_consistent(zone, page)) + return 1; + return 0; }