From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e36.co.us.ibm.com (8.13.1/8.13.1) with ESMTP id mA4FdMOO007883 for ; Tue, 4 Nov 2008 08:39:22 -0700 Received: from d03av03.boulder.ibm.com (d03av03.boulder.ibm.com [9.17.195.169]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id mA4Fdjsl032998 for ; Tue, 4 Nov 2008 08:39:45 -0700 Received: from d03av03.boulder.ibm.com (loopback [127.0.0.1]) by d03av03.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id mA4FditT029836 for ; Tue, 4 Nov 2008 08:39:45 -0700 Subject: Re: [linux-pm] [PATCH] hibernation should work ok with memory hotplug From: Dave Hansen In-Reply-To: <200811041635.49932.rjw@sisk.pl> References: <20081029105956.GA16347@atrey.karlin.mff.cuni.cz> <200811040954.34969.rjw@sisk.pl> <1225812111.12673.577.camel@nimitz> <200811041635.49932.rjw@sisk.pl> Content-Type: text/plain Date: Tue, 04 Nov 2008 07:39:42 -0800 Message-Id: <1225813182.12673.587.camel@nimitz> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: "Rafael J. Wysocki" Cc: Nigel Cunningham , Matt Tolentino , linux-pm@lists.osdl.org, Dave Hansen , linux-kernel@vger.kernel.org, linux-mm@kvack.org, pavel@suse.cz, Mel Gorman , Andy Whitcroft , Andrew Morton List-ID: On Tue, 2008-11-04 at 16:35 +0100, Rafael J. Wysocki wrote: > On Tuesday, 4 of November 2008, Dave Hansen wrote: > > On Tue, 2008-11-04 at 09:54 +0100, Rafael J. Wysocki wrote: > > > To handle this, I need to know two things: > > > 1) what changes of the zones are possible due to memory hotplugging > > > (i.e. can they grow, shring, change boundaries etc.) > > > > All of the above. > > OK > > If I allocate a page frame corresponding to specific pfn, is it guaranteed to > be associated with the same pfn in future? Page allocation is different. Since you hold a reference to a page, it can not be removed until you release that reference. That's why every normal alloc_pages() user in the kernel doesn't have to worry about memory hotplug. > > Why walk zones instead of pgdats? > > This is a historical thing rather than anything else. I think we could switch > to pgdats, but that would require a code rewrite that's likely to introduce > bugs, while our image-creating code is really well tested and doesn't change > very often. OK, fair enough. I just wanted you to know that there are options other than zones. -- Dave -- 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