From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752774AbaG1N7i (ORCPT ); Mon, 28 Jul 2014 09:59:38 -0400 Received: from mail.skyhub.de ([78.46.96.112]:33590 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751894AbaG1N7g (ORCPT ); Mon, 28 Jul 2014 09:59:36 -0400 Date: Mon, 28 Jul 2014 15:59:33 +0200 From: Borislav Petkov To: Joerg Roedel Cc: "Rafael J. Wysocki" , Pavel Machek , 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: <20140728135933.GA5918@pd.tnic> References: <1405938422-21900-1-git-send-email-joro@8bytes.org> <20140721160346.GP30979@8bytes.org> <20140721230500.GA7019@amd.pavel.ucw.cz> <6793803.1FXN0a3O0V@vostro.rjw.lan> <20140722103443.GV30979@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20140722103443.GV30979@8bytes.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 22, 2014 at 12:34:44PM +0200, Joerg Roedel wrote: > So my test was to resume from a swap partition that contained no image. > Here is the result from the 16GB machine. First with a v3.16-rc6 kernel > without my changes: > > kv:~/base # time perf record /usr/sbin/resume /dev/sda1 > resume: libgcrypt version: 1.5.3 > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.019 MB perf.data (~823 samples) ] > > real 0m0.084s > user 0m0.012s > sys 0m0.064s > > Here is the result with my patches on top: > > kv:~/hibernate # time perf record /usr/sbin/resume /dev/sda1 > resume: libgcrypt version: 1.5.3 > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.014 MB perf.data (~602 samples) ] > > real 0m0.032s > user 0m0.003s > sys 0m0.027s > > So we save around 50ms (or 62% of time) already on this 16GB machine. So, let's see, with Joerg's patches we - solve the issue on huge boxes. And yes, we most definitely want to be able to suspend them too. RAS is one very prominent use case here. *and* - we see improvement on smaller boxes, above numbers look good to me. and all that for an additional 8K for a S/R cycle?! And for some additional complexity of a radix tree which is self-contained, well tested and understood? This looks like certainly like net win to me. -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. --