From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750974AbaGUXFF (ORCPT ); Mon, 21 Jul 2014 19:05:05 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:53903 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750776AbaGUXFC (ORCPT ); Mon, 21 Jul 2014 19:05:02 -0400 Date: Tue, 22 Jul 2014 01:05:00 +0200 From: Pavel Machek To: Joerg Roedel Cc: "Rafael J. Wysocki" , Len Brown , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/6 v2] PM / Hibernate: Memory bitmap scalability improvements Message-ID: <20140721230500.GA7019@amd.pavel.ucw.cz> References: <1405938422-21900-1-git-send-email-joro@8bytes.org> <20140721120053.GA14069@amd.pavel.ucw.cz> <20140721123613.GL30979@8bytes.org> <20140721130629.GA15122@amd.pavel.ucw.cz> <20140721133800.GM30979@8bytes.org> <20140721141027.GA16042@amd.pavel.ucw.cz> <20140721160346.GP30979@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140721160346.GP30979@8bytes.org> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! On Mon 2014-07-21 18:03:46, Joerg Roedel wrote: > On Mon, Jul 21, 2014 at 04:10:27PM +0200, Pavel Machek wrote: > > > And Linux is only made for sane people? Thats pretty new to me ;-) > > > > Yeah, but please don't optimize for insane people :-). > > Thats rather discriminating, even more when you realize that 'insane' is > a very subjective attribute. You admitted you don't even have access to machine you are trying to optimize for. > > #6 is bugfix. We should take it. Rest is performance improvement for > > insane config. I don't think we should take it. > > Have you any other reason against these changes besides your > proven-to-be-wrong disbelief that it is necessary? Where you proven me wrong? If kernel is preparing bitmaps before checking resume signature, that is bug that costs you 60 seconds boot time on your 12TB machine. Fix that bug. It will benefit everyone. Software watchdog during hibernation on 12TB machine is a bug that hits insane people. Ok, lets fix it. Optimizing hibernation for memory-is-empty case is wrong. Linux tries to use as much memory as it can. Hibernating 12TB machine will take 5 hours or more. Redoing data structures to save 60 seconds of 5 hour process is not worth it. Nobody sane would hibernate 12TB machine. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html