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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 26197C3A5A6 for ; Mon, 23 Sep 2019 06:00:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ED0D120820 for ; Mon, 23 Sep 2019 06:00:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392273AbfIWGAZ (ORCPT ); Mon, 23 Sep 2019 02:00:25 -0400 Received: from mga06.intel.com ([134.134.136.31]:43150 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387519AbfIWGAZ (ORCPT ); Mon, 23 Sep 2019 02:00:25 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Sep 2019 23:00:25 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,539,1559545200"; d="scan'208";a="363524324" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by orsmga005.jf.intel.com with ESMTP; 22 Sep 2019 23:00:23 -0700 Date: Mon, 23 Sep 2019 14:00:05 +0800 From: Wei Yang To: Dave Hansen Cc: Wei Yang , dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86/mm: fix return value of p[um]dp_set_access_flags Message-ID: <20190923060005.GB7750@richard> Reply-To: Wei Yang References: <20190919082549.3895-1-richardw.yang@linux.intel.com> <307c9866-c037-5d87-709f-840bdb577283@intel.com> <20190920021821.GA8472@richard> <2fde036a-f64e-ce58-65bf-a089e7c673aa@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2fde036a-f64e-ce58-65bf-a089e7c673aa@intel.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 20, 2019 at 09:16:12AM -0700, Dave Hansen wrote: >On 9/19/19 7:18 PM, Wei Yang wrote: >> Last but not least, since update_mmu_cache_pmd is empty, even return >> value is not correct, it doesn't break anything. > >In other words, this patch has no functional effect and does not provide >a "fix". What's the point of patching this stuff if it has no effect? It correct the function semantics. The return value of these function doesn't meet the requirement, which will be misleading and we still need to dig in the history to find out the correct answer. In case we would have a valid cache update mechanism, this would introduce a problem. So I suggest to fix the return value to reflect the true meaning. -- Wei Yang Help you, Help me