From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 17 May 2006 14:48:41 +0900 From: Yasunori Goto Subject: Re: [PATCH] Register sysfs file for hotpluged new node In-Reply-To: <1147791091.6623.93.camel@localhost.localdomain> References: <20060516210608.A3E5.Y-GOTO@jp.fujitsu.com> <1147791091.6623.93.camel@localhost.localdomain> Message-Id: <20060517111236.21AC.Y-GOTO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Dave Hansen Cc: Andrew Morton , linux-mm , Linux Kernel ML List-ID: > On Tue, 2006-05-16 at 21:23 +0900, Yasunori Goto wrote: > > + /* > > + * register this node to sysfs. > > + * this is depends on topology. So each arch has its own. > > + */ > > + if (new_pgdat){ > > + ret = arch_register_node(nid); > > + BUG_ON(ret); > > + } > > Please don't do BUG_ON()s for things like this. Memory hotplug _should_ > handle failures from top to bottom and not screw you over. It isn't a > crime or a bug to be out of memory. Basically, I would like to agree. But, there is no way to roll back from here now. If online_node_map is set once, then new pgdat might be touched. There is no way to disable them. And I suppose it is not good thing that creating sysfs file of new node before setting online_node_map. It means user interface is shown before system initialization completion. (In addition, remove_memory() is not yet....) If return code of arch_register_node is ignored, cpu hotplug will work without new node's file. When we tried cpu hotplug on it, it was cause of stack dump at last. > Have you run this past the ppc maintainers? Nope. I just tried cross compile. I want powerpc box for test.... Thanks. -- Yasunori Goto -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org