From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2FD4AC33CAF for ; Mon, 13 Jan 2020 12:43:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0244021569 for ; Mon, 13 Jan 2020 12:43:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="fcyw21hM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726074AbgAMMnt (ORCPT ); Mon, 13 Jan 2020 07:43:49 -0500 Received: from merlin.infradead.org ([205.233.59.134]:33168 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725832AbgAMMnt (ORCPT ); Mon, 13 Jan 2020 07:43:49 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=Cl+a0Ksq5P2uxep+vtJZs+gr7i53uKQU6pt50ip33jo=; b=fcyw21hMSWLKxkn0vyj9yS8LY wTdB37m/bjABnGDJO3uV2yMcbzG0G9laSW8+lt2vO7890PInmOvbiEQOdxO9qLd5WROVTvEIH8bLg EANxWyZetCLm5G8Ikg53/8ubDWoDT1G2/VqkzbZJcE/TZjPcxXLers49AKrdse34lF5o4YG16a+0A C6dKSoxpr0MbLEWEW7aMfP90uKKBo1LNmKIJpJ1BeqRR6GdzFNSbxD4jJUn/mYqv6RkmQyX3XI/sB jZO1ErhSAKvhw+JvB/Paj64HFq+2BVsRVpS1ImhPasWC+CTBvY2Yf/ll0Ewpk4tuJWoeHvEJfTnoC OBKuZRRag==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1iqz3S-0004AK-FT; Mon, 13 Jan 2020 12:42:50 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 56D1D304121; Mon, 13 Jan 2020 13:41:12 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id AD5752B6B2F94; Mon, 13 Jan 2020 13:42:47 +0100 (CET) Date: Mon, 13 Jan 2020 13:42:47 +0100 From: Peter Zijlstra To: "Singh, Balbir" Cc: "Valentin, Eduardo" , "boris.ostrovsky@oracle.com" , "linux-kernel@vger.kernel.org" , "Agarwal, Anchal" , "Woodhouse, David" , "vkuznets@redhat.com" , "sstabellini@kernel.org" , "tglx@linutronix.de" , "linux-pm@vger.kernel.org" , "Woodhouse@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com" , "linux-mm@kvack.org" , "jgross@suse.com" , "pavel@ucw.cz" , "axboe@kernel.dk" , "x86@kernel.org" , "roger.pau@citrix.com" , "hpa@zytor.com" , "rjw@rjwysocki.net" , "mingo@redhat.com" , "Kamata, Munehisa" , "bp@alien8.de" , "netdev@vger.kernel.org" , "konrad.wilk@oracle.co" , "len.brown@intel.com" , "davem@davemloft.net" , "fllinden@amaozn.com" , "xen-devel@lists.xenproject.org" Subject: Re: [RFC PATCH V2 11/11] x86: tsc: avoid system instability in hibernation Message-ID: <20200113124247.GG2827@hirez.programming.kicks-ass.net> References: <20200107234526.GA19034@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> <20200108105011.GY2827@hirez.programming.kicks-ass.net> <20200110153520.GC8214@u40b0340c692b58f6553c.ant.amazon.com> <20200113101609.GT2844@hirez.programming.kicks-ass.net> <857b42b2e86b2ae09a23f488daada3b1b2836116.camel@amazon.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <857b42b2e86b2ae09a23f488daada3b1b2836116.camel@amazon.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Mon, Jan 13, 2020 at 11:43:18AM +0000, Singh, Balbir wrote: > For your original comment, just wanted to clarify the following: > > 1. After hibernation, the machine can be resumed on a different but compatible > host (these are VM images hibernated) > 2. This means the clock between host1 and host2 can/will be different > > In your comments are you making the assumption that the host(s) is/are the > same? Just checking the assumptions being made and being on the same page with > them. I would expect this to be the same problem we have as regular suspend, after power off the TSC will have been reset, so resume will have to somehow bridge that gap. I've no idea if/how it does that. I remember some BIOSes had crazy TSC ideas for suspend2ram, and we grew tsc_restore_sched_clock_state() for it. Playing crazy games like what you're doing just isn't it though.