From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Even if notifier cannot find any pages, it doesn't mean no pages are available...And, if there are no notifiers registered, this condition will be always true and memory hotplug will show -EBUSY. Clarification:This is a bug but not critical In most case, a pageblock which will be offlined is MIGRATE_MOVABLE This "notifier" is called only when the pageblock is _not_ MIGRATE_MOVABLE. But if not MIGRATE_MOVABLE, it's common case that memory hotplug will fail. So, no one notice this bug. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> --- mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: kametest/mm/page_alloc.c =================================================================== --- kametest.orig/mm/page_alloc.c +++ kametest/mm/page_alloc.c @@ -5313,7 +5313,7 @@ int set_migratetype_isolate(struct page */ notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg); notifier_ret = notifier_to_errno(notifier_ret); - if (notifier_ret || !arg.pages_found) + if (notifier_ret) goto out; for (iter = pfn; iter < (pfn + pageblock_nr_pages); iter++) { -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>