From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761411AbcALEHO (ORCPT ); Mon, 11 Jan 2016 23:07:14 -0500 Received: from TYO201.gate.nec.co.jp ([210.143.35.51]:41961 "EHLO tyo201.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758927AbcALEHL convert rfc822-to-8bit (ORCPT ); Mon, 11 Jan 2016 23:07:11 -0500 From: Naoya Horiguchi To: Andrew Morton CC: Andi Kleen , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , Naoya Horiguchi Subject: Re: [PATCH v1] mm: soft-offline: check return value in second __get_any_page() call Thread-Topic: [PATCH v1] mm: soft-offline: check return value in second __get_any_page() call Thread-Index: AQHRSeVeoHqUS9zphkuJSPbajvTt157wqDsAgAEH4gCABPgggA== Date: Tue, 12 Jan 2016 03:29:35 +0000 Message-ID: <20160112032932.GA8314@hori1.linux.bs1.fc.nec.co.jp> References: <1452237748-10822-1-git-send-email-n-horiguchi@ah.jp.nec.com> <20160108075158.GA28640@hori1.linux.bs1.fc.nec.co.jp> <20160108153626.16332573d71cdfcdbc1637cd@linux-foundation.org> In-Reply-To: <20160108153626.16332573d71cdfcdbc1637cd@linux-foundation.org> Accept-Language: ja-JP, en-US Content-Language: ja-JP X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.128.101.32] Content-Type: text/plain; charset="iso-2022-jp" Content-ID: Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 08, 2016 at 03:36:26PM -0800, Andrew Morton wrote: > On Fri, 8 Jan 2016 07:51:59 +0000 Naoya Horiguchi wrote: > > > > [ 52.600579] [] SyS_madvise+0x6bc/0x6f0 > > > [ 52.600579] [] ? fpu__restore_sig+0xcc/0x320 > > > [ 52.600579] [] ? do_sigaction+0x73/0x1b0 > > > [ 52.600579] [] ? __set_task_blocked+0x32/0x70 > > > [ 52.600579] [] entry_SYSCALL_64_fastpath+0x12/0x6a > > > [ 52.600579] Code: 8b fc ff ff 5b 5d c3 48 89 df e8 b0 fa ff ff 48 89 df 31 f6 e8 c6 7d ff ff 5b 5d c3 48 c7 c6 08 54 a2 81 48 89 df e8 a4 c5 01 00 <0f> 0b 66 90 66 66 66 66 90 55 48 89 e5 41 55 41 54 53 48 8b 47 > > > [ 52.600579] RIP [] put_page+0x5c/0x60 > > > [ 52.600579] RSP > > > > > > The root cause resides in get_any_page() which retries to get a refcount of > > > the page to be soft-offlined. This function calls put_hwpoison_page(), expecting > > > that the target page is putback to LRU list. But it can be also freed to buddy. > > > So the second check need to care about such case. > > > > > > Fixes: af8fae7c0886 ("mm/memory-failure.c: clean up soft_offline_page()") > > > Signed-off-by: Naoya Horiguchi > > > Cc: stable@vger.kernel.org # v3.9+ > > Please don't top-post. I manually fixed it here. sorry, I keep this rule in mind. > > Sorry, I forgot to notice that this specific problem is already fixed in > > mmotm with patch "mm: hwpoison: adjust for new thp refcounting", but > > considering backporting to -stable, it's easier to handle this separately. > > > > So Andrew, could you separate out the code of this patch from > > "mm: hwpoison: adjust for new thp refcounting"? > > I don't understand what you're asking for. Please be very > specific and carefully identify patches by filename or Subject:. OK, so what I really wanted is that (1) applying this patch just before http://ozlabs.org/~akpm/mmots/broken-out/mm-hwpoison-adjust-for-new-thp-refcounting.patch and (2) removing the following chunk from the mm-hwpoison-adjust-for-new-thp-refcounting.patch: @@ -1575,7 +1540,7 @@ static int get_any_page(struct page *pag * Did it turn free? */ ret = __get_any_page(page, pfn, 0); - if (!PageLRU(page)) { + if (ret == 1 && !PageLRU(page)) { /* Drop page reference which is from __get_any_page() */ put_hwpoison_page(page); pr_info("soft_offline: %#lx: unknown non LRU page type %lx\n", Thanks, Naoya Horiguchi