Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1753927AbeAHR2Q (ORCPT <rfc822;ralf@linux-mips.org> + 1 other);
        Mon, 8 Jan 2018 12:28:16 -0500
Received: from mga07.intel.com ([134.134.136.100]:55915 "EHLO mga07.intel.com"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1753772AbeAHR2O (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Mon, 8 Jan 2018 12:28:14 -0500
X-Amp-Result: SKIPPED(no attachment in message)
X-Amp-File-Uploaded: False
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="5.46,330,1511856000"; 
   d="scan'208";a="19256872"
Subject: Re: [PATCH v2 4/8] x86/spec_ctrl: Add sysctl knobs to enable/disable
 SPEC_CTRL feature
To: Peter Zijlstra <peterz@infradead.org>,
        Dave Hansen <dave.hansen@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
        Andy Lutomirski <luto@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Greg KH <gregkh@linuxfoundation.org>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Andi Kleen <ak@linux.intel.com>,
        Arjan Van De Ven <arjan.van.de.ven@intel.com>,
        David Woodhouse <dwmw@amazon.co.uk>,
        linux-kernel@vger.kernel.org
References: <cover.1515204614.git.tim.c.chen@linux.intel.com>
 <b77c0cfc2d50ebdaa721f95012fd735cc374f04c.1515204614.git.tim.c.chen@linux.intel.com>
 <d7413d40-7581-a994-5185-9f11c014cb0f@intel.com>
 <20180108124707.GH32035@hirez.programming.kicks-ass.net>
 <20180108161437.GN32035@hirez.programming.kicks-ass.net>
From: Tim Chen <tim.c.chen@linux.intel.com>
Message-ID: <46157295-e32e-5c9e-0c8b-f91b34f7b02d@linux.intel.com>
Date: Mon, 8 Jan 2018 09:28:12 -0800
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.1.0
MIME-Version: 1.0
In-Reply-To: <20180108161437.GN32035@hirez.programming.kicks-ass.net>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Return-Path: <linux-kernel-owner@vger.kernel.org>

On 01/08/2018 08:14 AM, Peter Zijlstra wrote:
> On Mon, Jan 08, 2018 at 01:47:07PM +0100, Peter Zijlstra wrote:
>>> a good suggestion, but we encountered some issues with it either
>>> crashing the kernel at boot or not properly turning on/off.
> 
> The below boots, but I lack stuff to test the enabling.

Peter,

Thanks.  Will give it a spin.  One other concern is if
JUMP_LABEL is not configured, this may not work, and
we may still need fall back to a control variable.

Tim