From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [RFC] Changing VM_PFNMAP assumptions and rules From: Benjamin Herrenschmidt Reply-To: benh@kernel.crashing.org In-Reply-To: <6934efce0711121553s6b88d1qe48b19adee1b7a85@mail.gmail.com> References: <6934efce0711091115i3f859a00id0b869742029b661@mail.gmail.com> <200711111109.34562.nickpiggin@yahoo.com.au> <6934efce0711121403h2623958cq49490077c586924f@mail.gmail.com> <1194906542.18185.73.camel@pasglop> <6934efce0711121553s6b88d1qe48b19adee1b7a85@mail.gmail.com> Content-Type: text/plain Date: Tue, 13 Nov 2007 11:24:33 +1100 Message-Id: <1194913473.18185.80.camel@pasglop> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Jared Hulbert Cc: Nick Piggin , Linux Memory Management List List-ID: On Mon, 2007-11-12 at 15:53 -0800, Jared Hulbert wrote: > > > I have a page that is at a hardware level read-only. What kind of > > > rules can that page live under? More importantly these PFN's get > > > mapped in with a call to ioremap() in the mtd drivers. So once I > > > figure out how to SPARSE_MEM, hotplug these pages in I've got to > hack > > > the MTD to work with real pages. Or something like that. I'm not > > > ready to take that on yet, I just don't understand it all enough > yet. > > > > I think vm_normal_page() could use something like pfn_normal() which > > isn't quite the same as pfn_valid()... or just use pfn_valid() but > in > > that case, that would mean removing a bunch of the BUG_ON's indeed. > > That's exactly what my original patch does. Would my patch break > spufs? Nick said my patch would break /dev/mem I think. I missed your original patch. Can you resend it to me ? Nick, how would it break /dev/mem ? Cheers, Ben. -- 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