From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4891C66A.3040302@linux-foundation.org> Date: Thu, 31 Jul 2008 09:04:26 -0500 From: Christoph Lameter MIME-Version: 1.0 Subject: Re: [RFC:Patch: 000/008](memory hotplug) rough idea of pgdat removing References: <20080731203549.2A3F.E1E9C6FF@jp.fujitsu.com> In-Reply-To: <20080731203549.2A3F.E1E9C6FF@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Yasunori Goto Cc: Badari Pulavarty , Andrew Morton , Mel Gorman , linux-mm , Linux Kernel ML List-ID: Yasunori Goto wrote: > Current my idea is using RCU feature for waiting them. > Because it is the least impact against reader's performance, > and pgdat remover can wait finish of reader's access to pgdat > which is removing by synchronize_sched(). The use of RCU disables preemption which has implications as to what can be done in a loop over nodes or zones. This would also potentially add more overhead to the page allocator hotpaths. > If you have better idea, please let me know. Use stop_machine()? The removal of a zone or node is a pretty rare event after all and it would avoid having to deal with rcu etc etc. -- 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