From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3CDA6C8E.462A3AE5@linux-m68k.org> Date: Thu, 09 May 2002 14:33:18 +0200 From: Roman Zippel MIME-Version: 1.0 Subject: Re: [PATCH] rmap 13a References: <20020507183741.A25245@infradead.org> <3CD96CB1.4630ED48@linux-m68k.org> <20020508213452.GJ15756@holomorphy.com> <3CD9A7FA.5967F675@linux-m68k.org> <20020508224255.GM15756@holomorphy.com> <3CD9B42A.69D38522@linux-m68k.org> <20020509012929.GO15756@holomorphy.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: William Lee Irwin III Cc: Christoph Hellwig , Rik van Riel , Samuel Ortiz , linux-mm@kvack.org List-ID: Hi, William Lee Irwin III wrote: > > You should not only look at the i386 code, if you want to create generic > > functions. > > It's not only i386. Other architectures are able to do likewise if > they satisfy the preconditions. And this is exactly one of four > variations, where all four together are able to handle all cases. > (In fact, just reverting to B works as a catch-all.) Your preconditions were no CONFIG_DISCONTIGMEM and no CONFIG_HIGHMEM. This is true for m68k, but it still breaks every single of your assumptions, but even on other archs where do these preconditions require physical memory to start at 0? > There doesn't seem to be enough depth to this subject to merit this > much discussion. Are we speaking at cross-purposes? Since I wrote a > bit of this, is there an issue you're having you'd like me to address? > I have a sun3 that's booted Linux in the past, so I might be able to > reproduce m68k-specific issues that arise. It's really not m68k specific. You are trying to generalize a very small part of the whole problem. First you only take some special cases (A. and B.) and the rest was completely arch specific so far. You have to define the complete model of how virtual and physical addresses and the pgdat/index tuple relate to each other, before you can generalize something of it. So far it was completely up to the archs to define this relationship with only little assumptions from the generic code. bye, Roman -- 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/