From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 14 Mar 2006 07:36:15 -0800 (PST) From: Christoph Lameter Subject: Re: [PATCH/RFC] AutoPage Migration - V0.1 - 1/8 migrate task memory with default policy In-Reply-To: <1142347567.5235.18.camel@localhost.localdomain> Message-ID: References: <1142019479.5204.15.camel@localhost.localdomain> <1142347567.5235.18.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Lee Schermerhorn Cc: linux-mm List-ID: On Tue, 14 Mar 2006, Lee Schermerhorn wrote: > > Could you add some special casing instead to migrate_to_node and/or > > check_range? > > I think this could be done. Don't know whether the results would be > "pretty" or not. Make it as pretty as possible. > Currently, you'll note that I'm calling check_range for one vma at a > time. I'm not sure this is a good idea. It probably adds overhead > revisiting upper level page table pages many times. But, I want to > compare different approaches. If I use migrate_to_node() and it's call > to check_range(), I would have to have something like the above logic to > do the per vma stuff. But, why per vma? I agree it doesn't make a lot > of sense for the kernel build workload. I find very few eligible pages > to migrate, so even if I scanned the entire mm at once, the resulting > page list would be very small. However, I was concerned about tying up > a large number of pages, isolated from the LRU, for applications with > larger footprints. I'm also going to experiment with more agressive Well if you just find a few pages to migrate then the pages isolated from the LRU will also be few. > migration--i.e., selecting pages with >1 map counts. This may result in > larger numbers of pages migrating. Yes and doing so may stall the concurrent compiler passes. > But, I have thought about adding internal flags to steer different paths > through migrate_to_node() and check_range(). If we ever get serious > about including an automigration mechanism like this, I'll go ahead and > take a look at it. Ok. -- 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