From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <436AB7CA.6060603@yahoo.com.au> Date: Fri, 04 Nov 2005 12:22:18 +1100 From: Nick Piggin MIME-Version: 1.0 Subject: Re: [Lhms-devel] [PATCH 0/7] Fragmentation Avoidance V19 References: <4366C559.5090504@yahoo.com.au> <1130854224.14475.60.camel@localhost><20051101142959.GA9272@elte.hu> <1130856555.14475.77.camel@localhost><20051101150142.GA10636@elte.hu> <1130858580.14475.98.camel@localhost><20051102084946.GA3930@elte.hu> <436880B8.1050207@yahoo.com.au><1130923969.15627.11.camel@localhost> <43688B74.20002@yahoo.com.au><255360000.1130943722@[10.10.2.4]> <4369824E.2020407@yahoo.com.au> <306020000.1131032193@[10.10.2.4]> <1131032422.2839.8.camel@laptopd505.fenrus.org> <309420000.1131036740@[10.10.2.4]> <311050000.1131040276@[10.10.2.4]> <1131040786.2839.18.camel@laptopd505.fenrus.org> <312300000.1131041824@[10.1! 0.2.4]> <436AB241.2030403@yahoo.com.au> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Linus Torvalds Cc: "Martin J. Bligh" , Arjan van de Ven , Mel Gorman , Dave Hansen , Ingo Molnar , Andrew Morton , kravetz@us.ibm.com, linux-mm , Linux Kernel Mailing List , lhms , Arjan van de Ven List-ID: Linus Torvalds wrote: > > On Fri, 4 Nov 2005, Nick Piggin wrote: > >>Looks like ppc64 is getting 64K page support, at which point higher >>order allocations (eg. for stacks) basically disappear don't they? > > > Yes and no, HOWEVER, nobody sane will ever use 64kB pages on a > general-purpose machine. > > 64kB pages are _only_ usable for databases, nothing else. > > Why? Do the math. Try to cache the whole kernel source tree in 4kB pages > vs 64kB pages. See how the memory usage goes up by a factor of _four_. > Yeah that's true. But Martin's worried about future machines with massive memories - so maybe it is safe to assume those will be using big pages, I don't know. Maybe the solution is to bloat the kernel sources enough to make 64KB pages worthwhile? -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com -- 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