From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751421AbeA2SJG (ORCPT ); Mon, 29 Jan 2018 13:09:06 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:55584 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751072AbeA2SJF (ORCPT ); Mon, 29 Jan 2018 13:09:05 -0500 Subject: Re: [PATCH v1] mm: hwpoison: disable memory error handling on 1GB hugepage To: Michal Hocko , Naoya Horiguchi Cc: Andrew Morton , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , Anshuman Khandual , "Aneesh Kumar K.V" References: <1517207283-15769-1-git-send-email-n-horiguchi@ah.jp.nec.com> <20180129063054.GA5205@hori1.linux.bs1.fc.nec.co.jp> <20180129095425.GA21609@dhcp22.suse.cz> From: Mike Kravetz Message-ID: Date: Mon, 29 Jan 2018 10:08:53 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 MIME-Version: 1.0 In-Reply-To: <20180129095425.GA21609@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8789 signatures=668655 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=9 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1801290235 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/29/2018 01:54 AM, Michal Hocko wrote: > On Mon 29-01-18 06:30:55, Naoya Horiguchi wrote: >> My apology, I forgot to CC to the mailing lists. >> >> On Mon, Jan 29, 2018 at 03:28:03PM +0900, Naoya Horiguchi wrote: >>> Recently the following BUG was reported: >>> >>> Injecting memory failure for pfn 0x3c0000 at process virtual address 0x7fe300000000 >>> Memory failure: 0x3c0000: recovery action for huge page: Recovered >>> BUG: unable to handle kernel paging request at ffff8dfcc0003000 >>> IP: gup_pgd_range+0x1f0/0xc20 >>> PGD 17ae72067 P4D 17ae72067 PUD 0 >>> Oops: 0000 [#1] SMP PTI >>> ... >>> CPU: 3 PID: 5467 Comm: hugetlb_1gb Not tainted 4.15.0-rc8-mm1-abc+ #3 >>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-1.fc25 04/01/2014 >>> >>> You can easily reproduce this by calling madvise(MADV_HWPOISON) twice on >>> a 1GB hugepage. This happens because get_user_pages_fast() is not aware >>> of a migration entry on pud that was created in the 1st madvise() event. > > Do pgd size pages work properly? Adding Anshuman and Aneesh as they added pgd support for power. And, this patch will disable that as well IIUC. This patch makes sense for x86. My only concern/question is for other archs which may have huge page sizes defined which are > MAX_ORDER and < PUD_SIZE. These would also be classified as gigantic and impacted by this patch. Do these also have the same issue? -- Mike Kravetz >>> I think that conversion to pud-aligned migration entry is working, >>> but other MM code walking over page table isn't prepared for it. >>> We need some time and effort to make all this work properly, so >>> this patch avoids the reported bug by just disabling error handling >>> for 1GB hugepage. > > Can we also get some documentation which would describe all requirements > for HWPoison pages to work properly please? > >>> Signed-off-by: Naoya Horiguchi > > Acked-by: Michal Hocko > > We probably want a backport to stable as well. Although regular process > cannot get giga pages easily without admin help it is still not nice to > oops like this. > >>> --- >>> include/linux/mm.h | 1 + >>> mm/memory-failure.c | 7 +++++++ >>> 2 files changed, 8 insertions(+) >>> >>> diff --git v4.15-rc8-mmotm-2018-01-18-16-31/include/linux/mm.h v4.15-rc8-mmotm-2018-01-18-16-31_patched/include/linux/mm.h >>> index 63f7ba1..166864e 100644 >>> --- v4.15-rc8-mmotm-2018-01-18-16-31/include/linux/mm.h >>> +++ v4.15-rc8-mmotm-2018-01-18-16-31_patched/include/linux/mm.h >>> @@ -2607,6 +2607,7 @@ enum mf_action_page_type { >>> MF_MSG_POISONED_HUGE, >>> MF_MSG_HUGE, >>> MF_MSG_FREE_HUGE, >>> + MF_MSG_GIGANTIC, >>> MF_MSG_UNMAP_FAILED, >>> MF_MSG_DIRTY_SWAPCACHE, >>> MF_MSG_CLEAN_SWAPCACHE, >>> diff --git v4.15-rc8-mmotm-2018-01-18-16-31/mm/memory-failure.c v4.15-rc8-mmotm-2018-01-18-16-31_patched/mm/memory-failure.c >>> index d530ac1..c497588 100644 >>> --- v4.15-rc8-mmotm-2018-01-18-16-31/mm/memory-failure.c >>> +++ v4.15-rc8-mmotm-2018-01-18-16-31_patched/mm/memory-failure.c >>> @@ -508,6 +508,7 @@ static const char * const action_page_types[] = { >>> [MF_MSG_POISONED_HUGE] = "huge page already hardware poisoned", >>> [MF_MSG_HUGE] = "huge page", >>> [MF_MSG_FREE_HUGE] = "free huge page", >>> + [MF_MSG_GIGANTIC] = "gigantic page", >>> [MF_MSG_UNMAP_FAILED] = "unmapping failed page", >>> [MF_MSG_DIRTY_SWAPCACHE] = "dirty swapcache page", >>> [MF_MSG_CLEAN_SWAPCACHE] = "clean swapcache page", >>> @@ -1090,6 +1091,12 @@ static int memory_failure_hugetlb(unsigned long pfn, int trapno, int flags) >>> return 0; >>> } >>> >>> + if (hstate_is_gigantic(page_hstate(head))) { >>> + action_result(pfn, MF_MSG_GIGANTIC, MF_IGNORED); >>> + res = -EBUSY; >>> + goto out; >>> + } >>> + >>> if (!hwpoison_user_mappings(p, pfn, trapno, flags, &head)) { >>> action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED); >>> res = -EBUSY; >>> -- >>> 2.7.0 >>> >>> >> -- >> 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 >