On Thu, 16 Dec 2010 10:26:41 +0000 Mel Gorman <mel@xxxxxxxxx> wrote: > Other than the spelling mistakes in the changelog and the lack of a > subject; > > Acked-by: Mel Gorman <mel@xxxxxxxxx> > Thank you. fixed one. == offline_pages()'s sanity check of given range is wrong. It should be aligned to MAX_ORDER. Current existing caller uses SECTION_SIZE alignment, so this change has no influence to existing callers. Reported-by: Ingo Korb <ingo@xxxxxxxx> Acked-by: Mel Gorman <mel@xxxxxxxxx> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> --- mm/memory_hotplug.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) Index: linux-2.6.37-rc5/mm/memory_hotplug.c =================================================================== --- linux-2.6.37-rc5.orig/mm/memory_hotplug.c +++ linux-2.6.37-rc5/mm/memory_hotplug.c @@ -798,10 +798,14 @@ static int offline_pages(unsigned long s struct memory_notify arg; BUG_ON(start_pfn >= end_pfn); - /* at least, alignment against pageblock is necessary */ - if (!IS_ALIGNED(start_pfn, pageblock_nr_pages)) + /* + * Considering Buddy system which joins nearby pages, the range + * in offline should be aligned to MAX_ORDER. If not, isolated + * page will be joined to other (not isolated) pages. + */ + if (!IS_ALIGNED(start_pfn, MAX_ORDER_NR_PAGES)) return -EINVAL; - if (!IS_ALIGNED(end_pfn, pageblock_nr_pages)) + if (!IS_ALIGNED(end_pfn, MAX_ORDER_NR_PAGES)) return -EINVAL; /* This makes hotplug much easier...and readable. we assume this for now. .*/ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>