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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_NEOMUTT autolearn=unavailable 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 15BF7C46470 for ; Fri, 31 May 2019 16:20:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DFC8F24894 for ; Fri, 31 May 2019 16:19:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726837AbfEaQT7 (ORCPT ); Fri, 31 May 2019 12:19:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45696 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726678AbfEaQT6 (ORCPT ); Fri, 31 May 2019 12:19:58 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 706A6C0A4F4C; Fri, 31 May 2019 16:19:58 +0000 (UTC) Received: from treble (ovpn-124-142.rdu2.redhat.com [10.10.124.142]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C20462FC59; Fri, 31 May 2019 16:19:56 +0000 (UTC) Date: Fri, 31 May 2019 11:19:52 -0500 From: Josh Poimboeuf To: Jiri Kosina Cc: Andy Lutomirski , Andy Lutomirski , "Rafael J. Wysocki" , "Rafael J. Wysocki" , Thomas Gleixner , the arch/x86 maintainers , Pavel Machek , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Peter Zijlstra , Linux PM , Linux Kernel Mailing List Subject: Re: [PATCH v4] x86/power: Fix 'nosmt' vs. hibernation triple fault during resume Message-ID: <20190531161952.dps3grwg4ytrpuqw@treble> References: <20190531051456.fzkvn62qlkf6wqra@treble> <5564116.e9OFvgDRbB@kreacher> <20190531152626.4nmyc7lj6mjwuo2v@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Fri, 31 May 2019 16:19:58 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 31, 2019 at 05:41:18PM +0200, Jiri Kosina wrote: > On Fri, 31 May 2019, Josh Poimboeuf wrote: > > > The only question I'd have is if we have data on the power savings > > difference between hlt and mwait. mwait seems to wake up on a lot of > > different conditions which might negate its deeper sleep state. > > hlt wakes up on basically the same set of events, but has the > auto-restarting semantics on some of them (especially SMM). So the wakeup > frequency itself shouldn't really contribute to power consumption > difference; it's the C-state that mwait allows CPU to enter. Ok. I reluctantly surrender :-) For your v4: Reviewed-by: Josh Poimboeuf It works as a short term fix, but it's fragile, and it does feel like we're just adding more duct tape, as Andy said. -- Josh