From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Wang Subject: Re: [PATCH] mm/page_poison: move PAGE_POISON to page_poison.c Date: Mon, 26 Feb 2018 12:37:58 +0800 Message-ID: <5A938F26.4040901@intel.com> References: <1518163694-27155-1-git-send-email-wei.w.wang@intel.com> <20180213101615.GO3443@dhcp22.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180213101615.GO3443@dhcp22.suse.cz> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Michal Hocko Cc: linux-mm@kvack.org, akpm@linux-foundation.org, mst@redhat.com, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org On 02/13/2018 06:16 PM, Michal Hocko wrote: > On Fri 09-02-18 16:08:14, Wei Wang wrote: >> The PAGE_POISON macro is used in page_poison.c only, so avoid exporting >> it. Also remove the "mm/debug-pagealloc.c" related comment, which is >> obsolete. > Why is this an improvement? I thought the whole point of poison.h is to > keep all the poison value at a single place to make them obviously > unique. There isn't a comment explaining why they are exposed. We did this because PAGE_POISON is used by page_poison.c only, it seems not necessary to expose the private values. Why would it be not unique if moved to page_poison.c (on condition that it is only used there)? Best, Wei From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f200.google.com (mail-pf0-f200.google.com [209.85.192.200]) by kanga.kvack.org (Postfix) with ESMTP id 79DC76B0005 for ; Sun, 25 Feb 2018 23:35:07 -0500 (EST) Received: by mail-pf0-f200.google.com with SMTP id u65so7795815pfd.7 for ; Sun, 25 Feb 2018 20:35:07 -0800 (PST) Received: from mga06.intel.com (mga06.intel.com. [134.134.136.31]) by mx.google.com with ESMTPS id p4si5058018pgf.656.2018.02.25.20.35.05 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 25 Feb 2018 20:35:06 -0800 (PST) Message-ID: <5A938F26.4040901@intel.com> Date: Mon, 26 Feb 2018 12:37:58 +0800 From: Wei Wang MIME-Version: 1.0 Subject: Re: [PATCH] mm/page_poison: move PAGE_POISON to page_poison.c References: <1518163694-27155-1-git-send-email-wei.w.wang@intel.com> <20180213101615.GO3443@dhcp22.suse.cz> In-Reply-To: <20180213101615.GO3443@dhcp22.suse.cz> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-mm@kvack.org, mst@redhat.com, akpm@linux-foundation.org On 02/13/2018 06:16 PM, Michal Hocko wrote: > On Fri 09-02-18 16:08:14, Wei Wang wrote: >> The PAGE_POISON macro is used in page_poison.c only, so avoid exporting >> it. Also remove the "mm/debug-pagealloc.c" related comment, which is >> obsolete. > Why is this an improvement? I thought the whole point of poison.h is to > keep all the poison value at a single place to make them obviously > unique. There isn't a comment explaining why they are exposed. We did this because PAGE_POISON is used by page_poison.c only, it seems not necessary to expose the private values. Why would it be not unique if moved to page_poison.c (on condition that it is only used there)? Best, Wei -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752164AbeBZEfH (ORCPT ); Sun, 25 Feb 2018 23:35:07 -0500 Received: from mga11.intel.com ([192.55.52.93]:20639 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751978AbeBZEfF (ORCPT ); Sun, 25 Feb 2018 23:35:05 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.47,396,1515484800"; d="scan'208";a="20336550" Message-ID: <5A938F26.4040901@intel.com> Date: Mon, 26 Feb 2018 12:37:58 +0800 From: Wei Wang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Michal Hocko CC: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-mm@kvack.org, mst@redhat.com, akpm@linux-foundation.org Subject: Re: [PATCH] mm/page_poison: move PAGE_POISON to page_poison.c References: <1518163694-27155-1-git-send-email-wei.w.wang@intel.com> <20180213101615.GO3443@dhcp22.suse.cz> In-Reply-To: <20180213101615.GO3443@dhcp22.suse.cz> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/13/2018 06:16 PM, Michal Hocko wrote: > On Fri 09-02-18 16:08:14, Wei Wang wrote: >> The PAGE_POISON macro is used in page_poison.c only, so avoid exporting >> it. Also remove the "mm/debug-pagealloc.c" related comment, which is >> obsolete. > Why is this an improvement? I thought the whole point of poison.h is to > keep all the poison value at a single place to make them obviously > unique. There isn't a comment explaining why they are exposed. We did this because PAGE_POISON is used by page_poison.c only, it seems not necessary to expose the private values. Why would it be not unique if moved to page_poison.c (on condition that it is only used there)? Best, Wei