when I test the memory online or offline, I find the problem that memory online always return an error. I peform the operation as follow: cd /sys/device/system/memory/ echo online > state it always print "-bash: echo: write error: Operation not permitted". By my alalysis, I find that the error happen in the memory_notifier(MEM_GOING_ONLINE,&arg) in the function(online_pages()). The problem occur in the latest kernel versin (linux 4.3.0 -rc4) , but In the lower version (linux 3.10) is correct. I think it may be caused by the confilct. Thanks zhongjiang -- 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>