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 D9E28C43334 for ; Mon, 11 Jul 2022 07:11:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229951AbiGKHLi (ORCPT ); Mon, 11 Jul 2022 03:11:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56110 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229931AbiGKHKz (ORCPT ); Mon, 11 Jul 2022 03:10:55 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8F0F1C924 for ; Mon, 11 Jul 2022 00:09:04 -0700 (PDT) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4LhFKy0c51zhZ3Q; Mon, 11 Jul 2022 15:06:30 +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, 11 Jul 2022 15:09:01 +0800 Subject: Re: [mm-unstable PATCH v5 4/8] mm, hwpoison: make unpoison aware of raw error info in hwpoisoned hugepage To: Naoya Horiguchi , CC: Andrew Morton , David Hildenbrand , Mike Kravetz , Liu Shixin , Yang Shi , Oscar Salvador , Muchun Song , Naoya Horiguchi , References: <20220708053653.964464-1-naoya.horiguchi@linux.dev> <20220708053653.964464-5-naoya.horiguchi@linux.dev> From: Miaohe Lin Message-ID: <3c66e7f6-e499-9802-409a-a32404fc87cc@huawei.com> Date: Mon, 11 Jul 2022 15:09:01 +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: <20220708053653.964464-5-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 2022/7/8 13:36, Naoya Horiguchi wrote: > From: Naoya Horiguchi > > Raw error info list needs to be removed when hwpoisoned hugetlb is > unpoisoned. And unpoison handler needs to know how many errors there > are in the target hugepage. So add them. > > HPageVmemmapOptimized(hpage) and HPageRawHwpUnreliable(hpage)) can't be > unpoisoned, so let's skip them. > > Signed-off-by: Naoya Horiguchi > Reported-by: kernel test robot > --- > v4 -> v5: > - fix type of return value of free_raw_hwp_pages() > (found by kernel test robot), > - prevent unpoison for HPageVmemmapOptimized and HPageRawHwpUnreliable. > --- > include/linux/swapops.h | 9 ++++++++ > mm/memory-failure.c | 50 ++++++++++++++++++++++++++++++++++++----- > 2 files changed, 53 insertions(+), 6 deletions(-) > > diff --git a/include/linux/swapops.h b/include/linux/swapops.h > index a01aeb3fcc0b..ddc98f96ad2c 100644 > --- a/include/linux/swapops.h > +++ b/include/linux/swapops.h > @@ -498,6 +498,11 @@ static inline void num_poisoned_pages_dec(void) > atomic_long_dec(&num_poisoned_pages); > } > > +static inline void num_poisoned_pages_sub(long i) > +{ > + atomic_long_sub(i, &num_poisoned_pages); > +} > + > #else > > static inline swp_entry_t make_hwpoison_entry(struct page *page) > @@ -518,6 +523,10 @@ static inline struct page *hwpoison_entry_to_page(swp_entry_t entry) > static inline void num_poisoned_pages_inc(void) > { > } > + > +static inline void num_poisoned_pages_sub(long i) > +{ > +} > #endif > > static inline int non_swap_entry(swp_entry_t entry) > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index 6833c5e4b410..89e74ec8a95f 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -1720,22 +1720,41 @@ static int hugetlb_set_page_hwpoison(struct page *hpage, struct page *page) > return ret; > } > > -int hugetlb_clear_page_hwpoison(struct page *hpage) > +static long free_raw_hwp_pages(struct page *hpage, bool move_flag) NO strong opinion: Maybe the return type should be "unsigned" as it always >= 0 ? > { > struct llist_head *head; > struct llist_node *t, *tnode; > + long count = 0; > > - if (!HPageRawHwpUnreliable(hpage)) > - ClearPageHWPoison(hpage); > + /* > + * HPageVmemmapOptimized hugepages can't be unpoisoned because > + * struct pages for tail pages are required to free hwpoisoned > + * hugepages. HPageRawHwpUnreliable hugepages shouldn't be > + * unpoisoned by definition. > + */ > + if (HPageVmemmapOptimized(hpage) || HPageRawHwpUnreliable(hpage)) > + return 0; > head = raw_hwp_list_head(hpage); > llist_for_each_safe(tnode, t, head->first) { > struct raw_hwp_page *p = container_of(tnode, struct raw_hwp_page, node); > > - SetPageHWPoison(p->page); > + if (move_flag) > + SetPageHWPoison(p->page); > kfree(p); > + count++; > } > llist_del_all(head); > - return 0; > + return count; > +} > + > +int hugetlb_clear_page_hwpoison(struct page *hpage) It seems the return value is unused? > +{ > + int ret = -EBUSY; > + > + if (!HPageRawHwpUnreliable(hpage)) > + ret = !TestClearPageHWPoison(hpage); > + free_raw_hwp_pages(hpage, true); > + return ret; > } > > /* > @@ -1879,6 +1898,10 @@ static inline int try_memory_failure_hugetlb(unsigned long pfn, int flags, int * > return 0; > } > > +static inline long free_raw_hwp_pages(struct page *hpage, bool move_flag) If return type is changed, remember to change here too. > +{ > + return 0; > +} > #endif /* CONFIG_HUGETLB_PAGE */ > > static int memory_failure_dev_pagemap(unsigned long pfn, int flags, > @@ -2284,6 +2307,7 @@ int unpoison_memory(unsigned long pfn) > struct page *p; > int ret = -EBUSY; > int freeit = 0; > + long count = 1; > static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL, > DEFAULT_RATELIMIT_BURST); > > @@ -2331,6 +2355,13 @@ int unpoison_memory(unsigned long pfn) > > ret = get_hwpoison_page(p, MF_UNPOISON); > if (!ret) { > + if (PageHuge(p)) { > + count = free_raw_hwp_pages(page, false); It seems the current behavior is: if any subpage of a hugetlb page is unpoisoned, then all of the hwpoisoned subpages will be unpoisoned. I'm not sure whether this is what we want. Thanks. > + if (count == 0) { > + ret = -EBUSY; > + goto unlock_mutex; > + } > + } > ret = TestClearPageHWPoison(page) ? 0 : -EBUSY; > } else if (ret < 0) { > if (ret == -EHWPOISON) { > @@ -2339,6 +2370,13 @@ int unpoison_memory(unsigned long pfn) > unpoison_pr_info("Unpoison: failed to grab page %#lx\n", > pfn, &unpoison_rs); > } else { > + if (PageHuge(p)) { > + count = free_raw_hwp_pages(page, false); > + if (count == 0) { > + ret = -EBUSY; > + goto unlock_mutex; > + } > + } > freeit = !!TestClearPageHWPoison(p); > > put_page(page); > @@ -2351,7 +2389,7 @@ int unpoison_memory(unsigned long pfn) > unlock_mutex: > mutex_unlock(&mf_mutex); > if (!ret || freeit) { > - num_poisoned_pages_dec(); > + num_poisoned_pages_sub(count); > unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n", > page_to_pfn(p), &unpoison_rs); > } >