From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 67BE0CCA473 for ; Mon, 27 Jun 2022 08:39:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233584AbiF0Ijt (ORCPT ); Mon, 27 Jun 2022 04:39:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232724AbiF0Ijr (ORCPT ); Mon, 27 Jun 2022 04:39:47 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8005662FA for ; Mon, 27 Jun 2022 01:39:45 -0700 (PDT) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.56]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4LWh3D3qGGz9s9Q; Mon, 27 Jun 2022 16:39:04 +0800 (CST) Received: from [10.174.177.76] (10.174.177.76) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Mon, 27 Jun 2022 16:39:42 +0800 Subject: Re: [PATCH v2 6/9] mm, hwpoison: set PG_hwpoison for busy hugetlb pages To: Naoya Horiguchi , CC: Andrew Morton , David Hildenbrand , Mike Kravetz , Liu Shixin , Yang Shi , Oscar Salvador , Muchun Song , Naoya Horiguchi , References: <20220623235153.2623702-1-naoya.horiguchi@linux.dev> <20220623235153.2623702-7-naoya.horiguchi@linux.dev> From: Miaohe Lin Message-ID: Date: Mon, 27 Jun 2022 16:39:42 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20220623235153.2623702-7-naoya.horiguchi@linux.dev> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.76] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/6/24 7:51, Naoya Horiguchi wrote: > From: Naoya Horiguchi > > If memory_failure() fails to grab page refcount on a hugetlb page > because it's busy, it returns without setting PG_hwpoison on it. > This not only loses a chance of error containment, but breaks the rule > that action_result() should be called only when memory_failure() do > any of handling work (even if that's just setting PG_hwpoison). > This inconsistency could harm code maintainability. > > So set PG_hwpoison and call hugetlb_set_page_hwpoison() for such a case. > > Fixes: 405ce051236c ("mm/hwpoison: fix race between hugetlb free/demotion and memory_failure_hugetlb()") > Signed-off-by: Naoya Horiguchi Reviewed-by: Miaohe Lin Thanks! > --- > include/linux/mm.h | 1 + > mm/memory-failure.c | 8 ++++---- > 2 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 4346e51484ba..044dc5a2e361 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -3233,6 +3233,7 @@ enum mf_flags { > MF_SOFT_OFFLINE = 1 << 3, > MF_UNPOISON = 1 << 4, > MF_SW_SIMULATED = 1 << 5, > + MF_NO_RETRY = 1 << 6, > }; > extern int memory_failure(unsigned long pfn, int flags); > extern void memory_failure_queue(unsigned long pfn, int flags); > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index 6005e953d011..ce045d0d6115 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -1632,7 +1632,8 @@ int __get_huge_page_for_hwpoison(unsigned long pfn, int flags) > count_increased = true; > } else { > ret = -EBUSY; > - goto out; > + if (!(flags & MF_NO_RETRY)) > + goto out; > } > > if (hugetlb_set_page_hwpoison(head, page)) { > @@ -1659,7 +1660,6 @@ static int try_memory_failure_hugetlb(unsigned long pfn, int flags, int *hugetlb > struct page *p = pfn_to_page(pfn); > struct page *head; > unsigned long page_flags; > - bool retry = true; > > *hugetlb = 1; > retry: > @@ -1675,8 +1675,8 @@ static int try_memory_failure_hugetlb(unsigned long pfn, int flags, int *hugetlb > } > return res; > } else if (res == -EBUSY) { > - if (retry) { > - retry = false; > + if (!(flags & MF_NO_RETRY)) { > + flags |= MF_NO_RETRY; > goto retry; > } > action_result(pfn, MF_MSG_UNKNOWN, MF_IGNORED); >