From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by e34.co.us.ibm.com (8.13.8/8.13.8) with ESMTP id l92N7mgk031607 for ; Tue, 2 Oct 2007 19:07:48 -0400 Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v8.5) with ESMTP id l92N7mdU456514 for ; Tue, 2 Oct 2007 17:07:48 -0600 Received: from d03av01.boulder.ibm.com (loopback [127.0.0.1]) by d03av01.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l92N7ljm017437 for ; Tue, 2 Oct 2007 17:07:47 -0600 Subject: Re: [RFC] PPC64 Exporting memory information through /proc/iomem From: Badari Pulavarty In-Reply-To: <18178.52359.953289.638736@cargo.ozlabs.ibm.com> References: <1191346196.6106.20.camel@dyn9047017100.beaverton.ibm.com> <18178.52359.953289.638736@cargo.ozlabs.ibm.com> Content-Type: text/plain Date: Tue, 02 Oct 2007 16:10:53 -0700 Message-Id: <1191366653.6106.68.camel@dyn9047017100.beaverton.ibm.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Paul Mackerras Cc: linuxppc-dev@ozlabs.org, linux-mm , anton@au1.ibm.com, KAMEZAWA Hiroyuki List-ID: On Wed, 2007-10-03 at 08:56 +1000, Paul Mackerras wrote: > Badari Pulavarty writes: > > > I am trying to get hotplug memory remove working on ppc64. > > In order to verify a given memory region, if its valid or not - > > current hotplug-memory patches used /proc/iomem. On IA64 and > > x86-64 /proc/iomem shows all memory regions. > > > > I am wondering, if its acceptable to do the same on ppc64 also ? > > I am a bit hesitant to do that, since /proc/iomem is user visible and > is therefore part of the user/kernel ABI. Also it feels a bit weird > to have system RAM in something whose name suggests it's about MMIO. Yes. That was my first reaction. Until last week, I never realized that /proc/iomem contains entire memory layout on i386/x86-64 :( Since i386, x86-64 and ia64 are all doing same thing, I thought breakage would be minimal (if any) if we do the same on ppc64. > > Otherwise, we need to add arch-specific hooks in hotplug-remove > > code to be able to do this. > > Isn't it just a matter of abstracting the test for a valid range of > memory? If it's really hard to abstract that, then I guess we can put > RAM in iomem_resource, but I'd rather not. > Sure. I will work on it and see how ugly it looks. KAME, are you okay with abstracting the find_next_system_ram() and let arch provide whatever implementation they want ? (since current code doesn't work for x86-64 also ?). Thanks, Badari -- 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