From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 15 Feb 2005 07:49:06 -0800 From: Paul Jackson Subject: Re: [RFC 2.6.11-rc2-mm2 7/7] mm: manual page migration -- sys_page_migrate Message-Id: <20050215074906.01439d4e.pj@sgi.com> In-Reply-To: <20050214220148.GA11832@lnx-holt.americas.sgi.com> References: <20050212032535.18524.12046.26397@tomahawk.engr.sgi.com> <20050212032620.18524.15178.29731@tomahawk.engr.sgi.com> <1108242262.6154.39.camel@localhost> <20050214135221.GA20511@lnx-holt.americas.sgi.com> <1108407043.6154.49.camel@localhost> <20050214220148.GA11832@lnx-holt.americas.sgi.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: Robin Holt Cc: haveblue@us.ibm.com, raybry@sgi.com, taka@valinux.co.jp, hugh@veritas.com, akpm@osdl.org, marcello@cyclades.com, raybry@austin.rr.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: Robin wrote: > Then how do you handle overlapping nodes. If I am doing a 5->4, 4->3, > 3->2, 2->1 shift ... Then do the shifts in the other order, first 2->1, then 3->2, ... So now you ask, what if you are doing a rotation? Use a temporary node: 2->tmp, 3->2, ..., N->(N-1), tmp->N. So now you ask, what if you are doing a rotation involving _all_ nodes, and have nothing you can use as a temporary node? Argh I say ... would anyone really do that? Or perhaps it makes sense to have the system call take a virtual address range (and hence a pid). In which case, you can do one page at a time, if need be, and get any foolhardy migration possible. Or perhaps some integration with Andi's mbind/mempolicy make sense. I'm not quite following Andi's comments on this, so I can't say one way or the other if this is good. -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson 1.650.933.1373, 1.925.600.0401 -- 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