From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <stable-owner@vger.kernel.org>
Received: from mga02.intel.com ([134.134.136.20]:52621 "EHLO mga02.intel.com"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1726134AbeLKUvN (ORCPT <rfc822;stable@vger.kernel.org>);
        Tue, 11 Dec 2018 15:51:13 -0500
Subject: Re: [PATCH V2] x86/intel_rdt: Ensure usage of CPUs are locked while
 needed
To: Borislav Petkov <bp@alien8.de>
Cc: tglx@linutronix.de, fenghua.yu@intel.com, tony.luck@intel.com,
        gavin.hindman@intel.com, jithu.joseph@intel.com, mingo@redhat.com,
        hpa@zytor.com, x86@kernel.org, linux-kernel@vger.kernel.org,
        stable@vger.kernel.org
References: <b7b17432a80f95a1fa21a1698ba643014f58ad31.1544476425.git.reinette.chatre@intel.com>
 <20181211123404.GC27375@zn.tnic>
 <ece2581e-d5e5-c26c-53e5-0cef8b37e59f@intel.com>
 <20181211185059.GP27375@zn.tnic>
 <e4ef2e81-defd-c5ca-4892-a0361a4528ba@intel.com>
 <20181211204310.GQ27375@zn.tnic>
From: Reinette Chatre <reinette.chatre@intel.com>
Message-ID: <10fef6af-785e-c76f-d89b-ec115dcf460a@intel.com>
Date: Tue, 11 Dec 2018 12:51:12 -0800
MIME-Version: 1.0
In-Reply-To: <20181211204310.GQ27375@zn.tnic>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: stable-owner@vger.kernel.org
List-ID: <stable.vger.kernel.org>

Hi Boris,

On 12/11/2018 12:43 PM, Borislav Petkov wrote:
> On Tue, Dec 11, 2018 at 11:02:08AM -0800, Reinette Chatre wrote:
>> I just wanted to emphasize that it is not the schemata writing that
>> needs to be protected, but instead the pseudo-locking code that runs
>> after schemata programming that needs to run on a particular CPU. The
>> new patch subject could be interpreted to mean the former ... but that
>> is starting to sound like nitpicking by me.
> 
> Nah, that's not nitpicking - it is important that we sort out stuff
> fully before committing.

I really appreciate your patience.

> 
> Now, I'm trying to understand what you're telling me and I believe you
> mean what update_domains() does, yes?

Yes.

> 
> And I guess a more fitting subject in that case could be:
> 
>   x86/intel_rdt: Ensure a CPU remains online for the region's pseudo-locking sequence
> 
> or so, and then the commit message explains in more detail what that
> title actually means. :)
> 
> Hmmm.

That subject line matches exactly the goal of this patch. Thank you very
much. Would you prefer that I send a new version with this subject line
or would you rather make the change yourself while applying this patch?

Reinette