From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755676Ab1GDIJu (ORCPT ); Mon, 4 Jul 2011 04:09:50 -0400 Received: from mtagate2.uk.ibm.com ([194.196.100.162]:53838 "EHLO mtagate2.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754403Ab1GDIJs (ORCPT ); Mon, 4 Jul 2011 04:09:48 -0400 Date: Mon, 4 Jul 2011 10:09:29 +0200 From: Martin Schwidefsky To: Pavel Machek Cc: "Rafael J. Wysocki" , linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, Jiri Slaby , Len Brown Subject: Re: [patch 1/1] [PATCH] include storage keys in hibernation image. Message-ID: <20110704100929.68674ea3@mschwide> In-Reply-To: <20110703174616.GB26790@elf.ucw.cz> References: <20110608074523.211912903@de.ibm.com> <201106121441.35059.rjw@sisk.pl> <20110614105001.2f991377@mschwide> <201106142250.15041.rjw@sisk.pl> <20110615093629.07f01779@mschwide> <20110703174616.GB26790@elf.ucw.cz> Organization: IBM Corporation X-Mailer: Claws Mail 3.7.9 (GTK+ 2.24.4; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 3 Jul 2011 19:46:16 +0200 Pavel Machek wrote: > Hi! > > > > I think, however, that we really should try to merge them. The only > > > difference seems to be how the additionally allocated pages will be populated > > > and what's going to happen to their contents during restore. > > > > > > ACPI will simply copy the NVS memory to those pages, while S390 will save > > > the relevant storage key bits in there. > > > > One complication to keep in mind is that we need to know which storage key > > goes to which page frame. We need something like the orig_bm/copy_bm or > > we'd have to store the pfn with the key. Simply storing the key for every > > page will make the array unnecessarily big. > > How big is the overhead? In percent / in megabytes? Well, that depends on the ratio of the size of the hibernation image and the total size of the ram. Consider a 1TB machine with a hibernation image size of lets say 128 GB. The hibernation image would require 32 MB worth of storage keys (0.024%), for 1TB the array size would be 256 MB (0.19%). -- blue skies, Martin. "Reality continues to ruin my life." - Calvin.