On Tue, 2013-07-30 at 14:49 +0800, Xishi Qiu wrote: > I think we can remove "BUG_ON(start_pfn >= end_pfn)" in __offline_pages(), > because in memory_block_action() "nr_pages = PAGES_PER_SECTION * sections_per_block" > is always greater than 0. BUG_ON() is used for checking a condition that should never happen, unless there is a bug. So, to me, what you described seems to match with the use of BUG_ON() to prevent a potential bug in the caller. Thanks, -Toshi > memory_block_action() > offline_pages() > __offline_pages() > BUG_ON(start_pfn >= end_pfn) > > Signed-off-by: Xishi Qiu <qiuxishi@xxxxxxxxxx> > --- > mm/memory_hotplug.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index ca1dd3a..8e333f9 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1472,7 +1472,6 @@ static int __ref __offline_pages(unsigned long start_pfn, > struct zone *zone; > 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)) > return -EINVAL; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>