From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <42161FBF.70200@sgi.com> Date: Fri, 18 Feb 2005 11:02:55 -0600 From: Ray Bryant MIME-Version: 1.0 Subject: Re: [RFC 2.6.11-rc2-mm2 0/7] mm: manual page migration -- overview II References: <20050212032535.18524.12046.26397@tomahawk.engr.sgi.com> <42114279.5070202@sgi.com> <20050215121404.GB25815@muc.de> <421241A2.8040407@sgi.com> <20050215214831.GC7345@wotan.suse.de> <4212C1A9.1050903@sgi.com> <20050217235437.GA31591@wotan.suse.de> In-Reply-To: <20050217235437.GA31591@wotan.suse.de> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andi Kleen Cc: Andi Kleen , Ray Bryant , linux-mm , linux-kernel List-ID: Andi Kleen wrote: > You and Robin mentioned some problems with "double migration" > with that, but it's still not completely clear to me what > problem you're solving here. Perhaps that needs to be reexamined. > > There is one other case where Robin and I have talked about double migration. That is the case where the set of old nodes and new nodes overlap. If one is not careful, and the system call interface is assumed to be something like: page_migrate(pid, old_node, new_node); then if one is not careful (and depending on what the complete list of old_nodes and new_nodes are), then if one does something like: page_migrate(pid, 1, 2); page_migrate(pid, 2, 3); then you can end up actually moving pages from node 1 to node 2, only to move them again from node 2 to node 3. This is another form of double migration that we have worried about avoiding. -- ----------------------------------------------- Ray Bryant 512-453-9679 (work) 512-507-7807 (cell) raybry@sgi.com raybry@austin.rr.com The box said: "Requires Windows 98 or better", so I installed Linux. ----------------------------------------------- -- 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: aart@kvack.org