From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932791AbcFASPX (ORCPT ); Wed, 1 Jun 2016 14:15:23 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:48137 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932640AbcFASPS (ORCPT ); Wed, 1 Jun 2016 14:15:18 -0400 Date: Wed, 1 Jun 2016 11:15:09 -0700 From: Guenter Roeck To: Borislav Petkov Cc: Ingo Molnar , linux-hwmon@vger.kernel.org, X86 ML , LKML , Rui Huang , Sherry Hurwitz Subject: Re: [PATCH] hwmon: (fam15h_power) Disable preemption when reading registers Message-ID: <20160601181509.GB10954@roeck-us.net> References: <1464775486-23446-1-git-send-email-bp@alien8.de> <574EE1B3.9010704@roeck-us.net> <20160601134126.GB22373@pd.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160601134126.GB22373@pd.tnic> User-Agent: Mutt/1.5.23 (2014-03-12) X-Authenticated_sender: guenter@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: guenter@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: guenter@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 01, 2016 at 03:41:26PM +0200, Borislav Petkov wrote: > On Wed, Jun 01, 2016 at 06:22:59AM -0700, Guenter Roeck wrote: > > An explanation would be helpful. Is this a bug fix ? > > That's a good point - yes, it is necessary. Both smp_processor_id() > *and* smp_call_function_many() need to be called with preemption > disabled. > > It did fire the BUG thing in check_preemption_disabled() with 4.7-rc1 > here without those fixes. > It would be great if you can add at least part of the BUG message as well as a Fixes: tag into the patch description. If you had, I would not have asked, saving both of us time ;-). > But, we need the other patch too - > > "[PATCH] x86/cpu/AMD: Extend X86_FEATURE_TOPOEXT workaround to newer models" > > because the cpumask generation in read_registers() doesn't work on those > Carrizo CPUs. > > IINM, the breakage came in during this merge window so we don't have to > CC:stable but both should be sent to Linus as fixes for 4.7. > > You could sync with Ingo who takes/acks what... but they could go > through tip and hwmon tree too, I don't see a hard dependency between > the two - they'd only need to be in 4.7-final. > Sounds like separate trees should be fine then. Thanks, Guenter