From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f71.google.com (mail-wm0-f71.google.com [74.125.82.71]) by kanga.kvack.org (Postfix) with ESMTP id F2D076B0038 for ; Tue, 12 Sep 2017 16:58:38 -0400 (EDT) Received: by mail-wm0-f71.google.com with SMTP id b68so11435131wme.4 for ; Tue, 12 Sep 2017 13:58:38 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id q25si9607140wrc.186.2017.09.12.13.58.38 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 12 Sep 2017 13:58:38 -0700 (PDT) Date: Tue, 12 Sep 2017 13:58:35 -0700 From: Andrew Morton Subject: Re: [PATCH] mm, hugetlb, soft_offline: save compound page order before page migration Message-Id: <20170912135835.0b48340ead5570e50529f676@linux-foundation.org> In-Reply-To: <20170912135448.341359676c6f8045f4a622f0@linux-foundation.org> References: <20170912204306.GA12053@gmail.com> <20170912135448.341359676c6f8045f4a622f0@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Alexandru Moise <00moses.alexander00@gmail.com>, linux-kernel@vger.kernel.org, khandual@linux.vnet.ibm.com, mhocko@suse.com, aarcange@redhat.com, minchan@kernel.org, hillf.zj@alibaba-inc.com, shli@fb.com, rppt@linux.vnet.ibm.com, kirill.shutemov@linux.intel.com, mgorman@techsingularity.net, rientjes@google.com, riel@redhat.com, linux-mm@kvack.org, Naoya Horiguchi On Tue, 12 Sep 2017 13:54:48 -0700 Andrew Morton wrote: > On Tue, 12 Sep 2017 22:43:06 +0200 Alexandru Moise <00moses.alexander00@gmail.com> wrote: > > > This fixes a bug in madvise() where if you'd try to soft offline a > > hugepage via madvise(), while walking the address range you'd end up, > > using the wrong page offset due to attempting to get the compound > > order of a former but presently not compound page, due to dissolving > > the huge page (since c3114a8). > > What are the user visible effects of the bug? The wrong page is > offlined? No offlining occurs? This also affects MADV_HWPOISON? -- 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