Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752711AbdFNPzD (ORCPT ); Wed, 14 Jun 2017 11:55:03 -0400 Received: from mga14.intel.com ([192.55.52.115]:14935 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752141AbdFNPzB (ORCPT ); Wed, 14 Jun 2017 11:55:01 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.39,340,1493708400"; d="scan'208";a="1141254978" Subject: Re: [PATCH v2 03/10] x86/mm: Give each mm TLB flush generation a unique ID To: Andy Lutomirski , x86@kernel.org References: <65ee83f8ef7259053e117355b0597b03ce096e07.1497415951.git.luto@kernel.org> Cc: linux-kernel@vger.kernel.org, Borislav Petkov , Linus Torvalds , Andrew Morton , Mel Gorman , "linux-mm@kvack.org" , Nadav Amit , Rik van Riel , Arjan van de Ven , Peter Zijlstra From: Dave Hansen Message-ID: <06ea73a2-f724-5b3e-5d9d-143d91ba94ae@intel.com> Date: Wed, 14 Jun 2017 08:54:55 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: <65ee83f8ef7259053e117355b0597b03ce096e07.1497415951.git.luto@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 313 Lines: 10 On 06/13/2017 09:56 PM, Andy Lutomirski wrote: > typedef struct { > + /* > + * ctx_id uniquely identifies this mm_struct. A ctx_id will never > + * be reused, and zero is not a valid ctx_id. > + */ > + u64 ctx_id; Ahh, and you need this because an mm itself might get reused by being freed and reallocated?