From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <42FB15C9.9050406@yahoo.com.au> Date: Thu, 11 Aug 2005 19:09:29 +1000 From: Nick Piggin MIME-Version: 1.0 Subject: Re: [RFC][patch 0/2] mm: remove PageReserved References: <42F57FCA.9040805@yahoo.com.au> <200508090710.00637.phillips@arcor.de> <1123562392.4370.112.camel@localhost> <42F83849.9090107@yahoo.com.au> <20050809080853.A25492@flint.arm.linux.org.uk> <523240000.1123598289@[10.10.2.4]> <20050809204100.B29945@flint.arm.linux.org.uk> <1123666046.30257.226.camel@gaston> In-Reply-To: <1123666046.30257.226.camel@gaston> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Benjamin Herrenschmidt Cc: Russell King , "Martin J. Bligh" , ncunningham@cyclades.com, Daniel Phillips , Linux Kernel Mailing List , Linux Memory Management , Hugh Dickins , Linus Torvalds , Andrew Morton , Andrea Arcangeli List-ID: Benjamin Herrenschmidt wrote: > On Tue, 2005-08-09 at 20:41 +0100, Russell King wrote: > >>On Tue, Aug 09, 2005 at 07:38:52AM -0700, Martin J. Bligh wrote: >> >>>pfn_valid() doesn't tell you it's RAM or not - it tells you whether you >>>have a backing struct page for that address. Could be an IO mapped device, >>>a small memory hole, whatever. >> >>The only things which have a struct page is RAM. Nothing else does. > > > Well, not anymore :) > Well thanks everyone for the discussion and input. If I have missed answering a question, please just mail me privately to let me know. I guess that despite some architecture implementation differences, everyone will be happy to see PageReserved go from core code. So I will send Andrew the patches. After that, we have a few options to move forward with completely getting rid of the flag from the other funny places it has cropped up. A portable page_is_ram() sounds like the best way to go, as it would not use up a page flag. As far as ioremap goes - I would rather completely disallow it from remapping physical pages and enforce that where possible (eg. with page_is_ram()). However, these issues (page_is_ram, swsusp, ioremap) need not be tackled right now. I will bring them up on the lists some time after the core mm/ is working nicely without PageReserved. Thanks, Nick -- 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