From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ie0-f174.google.com (mail-ie0-f174.google.com [209.85.223.174]) by kanga.kvack.org (Postfix) with ESMTP id A2B9390001D for ; Tue, 11 Nov 2014 21:10:37 -0500 (EST) Received: by mail-ie0-f174.google.com with SMTP id x19so12743547ier.19 for ; Tue, 11 Nov 2014 18:10:37 -0800 (PST) Received: from mail-ig0-x22e.google.com (mail-ig0-x22e.google.com. [2607:f8b0:4001:c05::22e]) by mx.google.com with ESMTPS id y8si34524105icl.32.2014.11.11.18.10.36 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 11 Nov 2014 18:10:36 -0800 (PST) Received: by mail-ig0-f174.google.com with SMTP id hn18so2164651igb.1 for ; Tue, 11 Nov 2014 18:10:36 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20141111142344.b4eb11c6e3c240d345fdd995@linux-foundation.org> References: <000001cff998$ee0b31d0$ca219570$%yang@samsung.com> <20141111142344.b4eb11c6e3c240d345fdd995@linux-foundation.org> Date: Wed, 12 Nov 2014 10:10:36 +0800 Message-ID: Subject: Re: [PATCH 1/2] mm: page_isolation: check pfn validity before access From: Weijie Yang Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Weijie Yang , kamezawa.hiroyu@jp.fujitsu.com, Minchan Kim , mgorman@suse.de, mina86@mina86.com, linux-kernel , Linux-MM , isimatu.yasuaki@jp.fujitsu.com On Wed, Nov 12, 2014 at 6:23 AM, Andrew Morton wrote: > On Thu, 06 Nov 2014 16:08:02 +0800 Weijie Yang wrote: > >> In the undo path of start_isolate_page_range(), we need to check >> the pfn validity before access its page, or it will trigger an >> addressing exception if there is hole in the zone. >> > > There is not enough information in the chagnelog for me to decide how > to handle the patch. 3.19? 3.18? 3.18+stable? > > When fixing bugs, please remember to fully explain the end-user impact > of the bug. Under what circumstances does it occur? I'm sorry to disturb you. This issue is found by code-review not a test-trigger. In "CONFIG_HOLES_IN_ZONE" environment, there is a certain chance that it would casue an addressing exception when start_isolate_page_range() fails, this could affect CMA, hugepage and memory-hotplug function. -- 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