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 CAA22C4332F for ; Sat, 15 Oct 2022 02:28:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229622AbiJOC2I (ORCPT ); Fri, 14 Oct 2022 22:28:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33686 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229608AbiJOC2F (ORCPT ); Fri, 14 Oct 2022 22:28:05 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 927B363872 for ; Fri, 14 Oct 2022 19:28:03 -0700 (PDT) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4Mq6Xb4p3VzpVw7; Sat, 15 Oct 2022 10:24:47 +0800 (CST) Received: from [10.174.151.185] (10.174.151.185) 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 15.1.2375.31; Sat, 15 Oct 2022 10:28:01 +0800 Subject: Re: [PATCH v6 4/4] mm/hwpoison: introduce per-memory_block hwpoison counter To: Naoya Horiguchi , CC: Andrew Morton , David Hildenbrand , Mike Kravetz , Yang Shi , Oscar Salvador , Muchun Song , Jane Chu , Naoya Horiguchi , References: <20221007010706.2916472-1-naoya.horiguchi@linux.dev> <20221007010706.2916472-5-naoya.horiguchi@linux.dev> From: Miaohe Lin Message-ID: <3a6e403d-15d1-f419-698a-b1c825f59472@huawei.com> Date: Sat, 15 Oct 2022 10:28:00 +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: <20221007010706.2916472-5-naoya.horiguchi@linux.dev> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.151.185] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) 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 2022/10/7 9:07, Naoya Horiguchi wrote: > From: Naoya Horiguchi > > Currently PageHWPoison flag does not behave well when experiencing memory > hotremove/hotplug. Any data field in struct page is unreliable when the > associated memory is offlined, and the current mechanism can't tell whether > a memory block is onlined because a new memory devices is installed or > because previous failed offline operations are undone. Especially if > there's a hwpoisoned memory, it's unclear what the best option is. > > So introduce a new mechanism to make struct memory_block remember that > a memory block has hwpoisoned memory inside it. And make any online event > fail if the onlining memory block contains hwpoison. struct memory_block > is freed and reallocated over ACPI-based hotremove/hotplug, but not over > sysfs-based hotremove/hotplug. So the new counter can distinguish these > cases. > > Signed-off-by: Naoya Horiguchi > Reported-by: kernel test robot > --- > ChangeLog v5 -> v6: > - fix build errors over memblk_nr_poison_inc() and memblk_nr_poison_sub(), > - pass "struct memory_block *" to memblk_nr_poison() instead of pfn, > - removed clear_hwpoisoned_pages() and call num_poisoned_pages_sub() directly. > - add static keyword to the definition of memblk_nr_poison(). > - Mioahe added Reviewed-by for v5, but I have some non trivial changes in > v6, so let me hold to add it. > - unpoison_memory() properly cancels per-memblk hwpoison counter. > > ChangeLog v4 -> v5: > - add Reported-by of lkp bot, > - check both CONFIG_MEMORY_FAILURE and CONFIG_MEMORY_HOTPLUG in introduced #ifdefs, > intending to fix "undefined reference" errors in aarch64. > > ChangeLog v3 -> v4: > - fix build error (https://lore.kernel.org/linux-mm/202209231134.tnhKHRfg-lkp@intel.com/) > by using memblk_nr_poison() to access to the member ->nr_hwpoison > --- > drivers/base/memory.c | 40 ++++++++++++++++++++++++++++++++++++++++ > include/linux/memory.h | 3 +++ > include/linux/mm.h | 18 ++++++++++++++++++ > mm/internal.h | 8 -------- > mm/memory-failure.c | 36 +++++++++++------------------------- > mm/sparse.c | 2 -- > 6 files changed, 72 insertions(+), 35 deletions(-) > > diff --git a/drivers/base/memory.c b/drivers/base/memory.c > index 9aa0da991cfb..5d00d8a14c79 100644 > --- a/drivers/base/memory.c > +++ b/drivers/base/memory.c > @@ -175,6 +175,17 @@ int memory_notify(unsigned long val, void *v) > return blocking_notifier_call_chain(&memory_chain, val, v); > } > > +#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG) > +void memblk_nr_poison_inc(unsigned long pfn); > +void memblk_nr_poison_sub(unsigned long pfn, long i); > +static unsigned long memblk_nr_poison(struct memory_block *mem); > +#else > +static inline unsigned long memblk_nr_poison(struct memory_block *mem) > +{ > + return 0; > +} > +#endif > + > static int memory_block_online(struct memory_block *mem) > { > unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr); > @@ -183,6 +194,9 @@ static int memory_block_online(struct memory_block *mem) > struct zone *zone; > int ret; > > + if (memblk_nr_poison(mem)) > + return -EHWPOISON; > + > zone = zone_for_pfn_range(mem->online_type, mem->nid, mem->group, > start_pfn, nr_pages); > > @@ -864,6 +878,7 @@ void remove_memory_block_devices(unsigned long start, unsigned long size) > mem = find_memory_block_by_id(block_id); > if (WARN_ON_ONCE(!mem)) > continue; > + num_poisoned_pages_sub(-1UL, memblk_nr_poison(mem)); > unregister_memory_block_under_nodes(mem); > remove_memory_block(mem); > } > @@ -1164,3 +1179,28 @@ int walk_dynamic_memory_groups(int nid, walk_memory_groups_func_t func, > } > return ret; > } > + > +#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG) > +void memblk_nr_poison_inc(unsigned long pfn) > +{ > + const unsigned long block_id = pfn_to_block_id(pfn); > + struct memory_block *mem = find_memory_block_by_id(block_id); > + > + if (mem) > + atomic_long_inc(&mem->nr_hwpoison); > +} > + > +void memblk_nr_poison_sub(unsigned long pfn, long i) > +{ > + const unsigned long block_id = pfn_to_block_id(pfn); > + struct memory_block *mem = find_memory_block_by_id(block_id); > + > + if (mem) > + atomic_long_sub(i, &mem->nr_hwpoison); > +} > + > +static unsigned long memblk_nr_poison(struct memory_block *mem) > +{ > + return atomic_long_read(&mem->nr_hwpoison); > +} > +#endif > diff --git a/include/linux/memory.h b/include/linux/memory.h > index aa619464a1df..ad8cd9bb3239 100644 > --- a/include/linux/memory.h > +++ b/include/linux/memory.h > @@ -85,6 +85,9 @@ struct memory_block { > unsigned long nr_vmemmap_pages; > struct memory_group *group; /* group (if any) for this block */ > struct list_head group_next; /* next block inside memory group */ > +#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG) > + atomic_long_t nr_hwpoison; > +#endif > }; > > int arch_get_memory_phys_device(unsigned long start_pfn); > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 17119dbf8fad..f80269e90772 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -3280,6 +3280,7 @@ extern int soft_offline_page(unsigned long pfn, int flags); > extern int __get_huge_page_for_hwpoison(unsigned long pfn, int flags, > bool *migratable_cleared); > extern void num_poisoned_pages_inc(unsigned long pfn); > +extern void num_poisoned_pages_sub(unsigned long pfn, long i); The prototype of this function is: *inline* void num_poisoned_pages_sub(unsigned long pfn, long i). The combination of inline and extern looks weird to me. Is this a common use case? Anyway, this patch looks good to me. Thanks. Reviewed-by: Miaohe Lin Thanks, Miaohe Lin