From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757922Ab3BEWUU (ORCPT ); Tue, 5 Feb 2013 17:20:20 -0500 Received: from e8.ny.us.ibm.com ([32.97.182.138]:34714 "EHLO e8.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757557Ab3BEWUR (ORCPT ); Tue, 5 Feb 2013 17:20:17 -0500 Message-ID: <5111859B.7060004@linux.vnet.ibm.com> Date: Tue, 05 Feb 2013 14:20:11 -0800 From: Cody P Schafer User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: Andrew Morton CC: Linux MM , David Hansen , LKML , Catalin Marinas Subject: Re: [PATCH 6/9] mm/page_alloc: add informative debugging message in page_outside_zone_boundaries() References: <1358463181-17956-1-git-send-email-cody@linux.vnet.ibm.com> <1358463181-17956-7-git-send-email-cody@linux.vnet.ibm.com> <20130201162848.74bdb2a7.akpm@linux-foundation.org> <20130201162957.3ec618cf.akpm@linux-foundation.org> In-Reply-To: <20130201162957.3ec618cf.akpm@linux-foundation.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13020522-9360-0000-0000-000010335783 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/01/2013 04:29 PM, Andrew Morton wrote: > On Fri, 1 Feb 2013 16:28:48 -0800 > Andrew Morton wrote: > >>> + if (ret) >>> + pr_debug("page %lu outside zone [ %lu - %lu ]\n", >>> + pfn, start_pfn, start_pfn + sp); >>> + >>> return ret; >>> } >> >> As this condition leads to a VM_BUG_ON(), "pr_debug" seems rather wimpy >> and I doubt if we need to be concerned about flooding the console. >> >> I'll switch it to pr_err. > > otoh, as nobody has ever hit that VM_BUG_ON() (yes?), do we really need > the patch? I've hit this bug while developing some code that moves pages between zones. As it helped me debug that issue with my own code, I could see how another developer might be helped by it. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx182.postini.com [74.125.245.182]) by kanga.kvack.org (Postfix) with SMTP id 1F4EE6B0007 for ; Tue, 5 Feb 2013 17:20:18 -0500 (EST) Received: from /spool/local by e8.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 5 Feb 2013 17:20:17 -0500 Received: from d01relay03.pok.ibm.com (d01relay03.pok.ibm.com [9.56.227.235]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id 6BED46E801C for ; Tue, 5 Feb 2013 17:20:11 -0500 (EST) Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay03.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r15MKCiV296036 for ; Tue, 5 Feb 2013 17:20:12 -0500 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r15MKCbC000850 for ; Tue, 5 Feb 2013 20:20:12 -0200 Message-ID: <5111859B.7060004@linux.vnet.ibm.com> Date: Tue, 05 Feb 2013 14:20:11 -0800 From: Cody P Schafer MIME-Version: 1.0 Subject: Re: [PATCH 6/9] mm/page_alloc: add informative debugging message in page_outside_zone_boundaries() References: <1358463181-17956-1-git-send-email-cody@linux.vnet.ibm.com> <1358463181-17956-7-git-send-email-cody@linux.vnet.ibm.com> <20130201162848.74bdb2a7.akpm@linux-foundation.org> <20130201162957.3ec618cf.akpm@linux-foundation.org> In-Reply-To: <20130201162957.3ec618cf.akpm@linux-foundation.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Linux MM , David Hansen , LKML , Catalin Marinas On 02/01/2013 04:29 PM, Andrew Morton wrote: > On Fri, 1 Feb 2013 16:28:48 -0800 > Andrew Morton wrote: > >>> + if (ret) >>> + pr_debug("page %lu outside zone [ %lu - %lu ]\n", >>> + pfn, start_pfn, start_pfn + sp); >>> + >>> return ret; >>> } >> >> As this condition leads to a VM_BUG_ON(), "pr_debug" seems rather wimpy >> and I doubt if we need to be concerned about flooding the console. >> >> I'll switch it to pr_err. > > otoh, as nobody has ever hit that VM_BUG_ON() (yes?), do we really need > the patch? I've hit this bug while developing some code that moves pages between zones. As it helped me debug that issue with my own code, I could see how another developer might be helped by it. -- 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