From nobody Thu Apr 2 21:45:38 2026 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 6B6DDC32771 for ; Wed, 21 Sep 2022 09:17:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231178AbiIUJRR (ORCPT ); Wed, 21 Sep 2022 05:17:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50780 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231577AbiIUJQp (ORCPT ); Wed, 21 Sep 2022 05:16:45 -0400 Received: from out2.migadu.com (out2.migadu.com [IPv6:2001:41d0:2:aacc::]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BFC708E4CD for ; Wed, 21 Sep 2022 02:16:13 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1663751768; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=K3zq9Vv1YEJefxa5eePts00URoMHA6ZGQVN+sMjAFVQ=; b=og2aD95owl2UUJSYB7yl/LK1wbBgowpMLV3NHO5IIDxCxdxa5W0Vkz0XEyYAv/P0nrIkQo QK5+LOPnl5Oa9RceYDFbWZ37OdngjR6EsESWaRcwr+9uYJleD695+ZRJNWqlEqvLlkWUPl HLQoWb324EnTiQP5gTEYaMGvWH6yTtY= From: Naoya Horiguchi To: linux-mm@kvack.org Cc: Andrew Morton , Miaohe Lin , David Hildenbrand , Mike Kravetz , Yang Shi , Oscar Salvador , Muchun Song , Jane Chu , Naoya Horiguchi , linux-kernel@vger.kernel.org Subject: [PATCH v3 4/4] mm/hwpoison: introduce per-memory_block hwpoison counter Date: Wed, 21 Sep 2022 18:13:59 +0900 Message-Id: <20220921091359.25889-5-naoya.horiguchi@linux.dev> In-Reply-To: <20220921091359.25889-1-naoya.horiguchi@linux.dev> References: <20220921091359.25889-1-naoya.horiguchi@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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 section 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 onlined memory block contains hwpoison. struct memory_block is freed and reallocated over ACPI-based hotremove/hotplug, but not over sysfs-based hotremove/hotplug. So it's desirable to implement hwpoison counter on this struct. Note that clear_hwpoisoned_pages() is relocated to be called earlier than now, just before unregistering struct memory_block. Otherwise, the per-memory_block hwpoison counter is freed and we fail to adjust global hwpoison counter properly. Signed-off-by: Naoya Horiguchi --- drivers/base/memory.c | 36 ++++++++++++++++++++++++++++++++++++ include/linux/memory.h | 3 +++ include/linux/mm.h | 8 ++++++++ mm/internal.h | 8 -------- mm/memory-failure.c | 31 ++++++++++--------------------- mm/sparse.c | 2 -- 6 files changed, 57 insertions(+), 31 deletions(-) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 9aa0da991cfb..c9bde4c4ffdf 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -183,6 +183,9 @@ static int memory_block_online(struct memory_block *mem) struct zone *zone; int ret; =20 + if (atomic_long_read(&mem->nr_hwpoison)) + return -EHWPOISON; + zone =3D zone_for_pfn_range(mem->online_type, mem->nid, mem->group, start_pfn, nr_pages); =20 @@ -864,6 +867,7 @@ void remove_memory_block_devices(unsigned long start, u= nsigned long size) mem =3D find_memory_block_by_id(block_id); if (WARN_ON_ONCE(!mem)) continue; + clear_hwpoisoned_pages(atomic_long_read(&mem->nr_hwpoison)); unregister_memory_block_under_nodes(mem); remove_memory_block(mem); } @@ -1164,3 +1168,35 @@ int walk_dynamic_memory_groups(int nid, walk_memory_= groups_func_t func, } return ret; } + +#ifdef CONFIG_MEMORY_FAILURE + +void memblk_nr_poison_inc(unsigned long pfn) +{ + const unsigned long block_id =3D pfn_to_block_id(pfn); + struct memory_block *mem =3D 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 =3D pfn_to_block_id(pfn); + struct memory_block *mem =3D find_memory_block_by_id(block_id); + + if (mem) + atomic_long_sub(i, &mem->nr_hwpoison); +} + +unsigned long memblk_nr_poison(unsigned long pfn) +{ + const unsigned long block_id =3D pfn_to_block_id(pfn); + struct memory_block *mem =3D find_memory_block_by_id(block_id); + + if (mem) + return atomic_long_read(&mem->nr_hwpoison); + return 0; +} + +#endif diff --git a/include/linux/memory.h b/include/linux/memory.h index aa619464a1df..74e6b3ad947f 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 */ +#ifdef CONFIG_MEMORY_FAILURE + atomic_long_t nr_hwpoison; +#endif }; =20 int arch_get_memory_phys_device(unsigned long start_pfn); diff --git a/include/linux/mm.h b/include/linux/mm.h index 2bb5d1596041..2fe42bb9a517 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3280,6 +3280,10 @@ extern int soft_offline_page(unsigned long pfn, int = flags); #ifdef CONFIG_MEMORY_FAILURE extern int __get_huge_page_for_hwpoison(unsigned long pfn, int flags); extern void num_poisoned_pages_inc(unsigned long pfn); +extern void memblk_nr_poison_inc(unsigned long pfn); +extern void memblk_nr_poison_sub(unsigned long pfn, long i); +extern unsigned long memblk_nr_poison(unsigned long pfn); +extern void clear_hwpoisoned_pages(long nr_poison); #else static inline int __get_huge_page_for_hwpoison(unsigned long pfn, int flag= s) { @@ -3289,6 +3293,10 @@ static inline int __get_huge_page_for_hwpoison(unsig= ned long pfn, int flags) static inline void num_poisoned_pages_inc(unsigned long pfn) { } + +static inline void clear_hwpoisoned_pages(long nr_poison) +{ +} #endif =20 #ifndef arch_memory_failure diff --git a/mm/internal.h b/mm/internal.h index b3002e03c28f..42ba8b96cab5 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -708,14 +708,6 @@ extern u64 hwpoison_filter_flags_value; extern u64 hwpoison_filter_memcg; extern u32 hwpoison_filter_enable; =20 -#ifdef CONFIG_MEMORY_FAILURE -void clear_hwpoisoned_pages(struct page *memmap, int nr_pages); -#else -static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_page= s) -{ -} -#endif - extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned l= ong, unsigned long, unsigned long, unsigned long, unsigned long); diff --git a/mm/memory-failure.c b/mm/memory-failure.c index a069d43bc87f..03479895086d 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -74,14 +74,17 @@ atomic_long_t num_poisoned_pages __read_mostly =3D ATOM= IC_LONG_INIT(0); =20 static bool hw_memory_failure __read_mostly =3D false; =20 -static inline void num_poisoned_pages_inc(unsigned long pfn) +void num_poisoned_pages_inc(unsigned long pfn) { atomic_long_inc(&num_poisoned_pages); + memblk_nr_poison_inc(pfn); } =20 static inline void num_poisoned_pages_sub(unsigned long pfn, long i) { atomic_long_sub(i, &num_poisoned_pages); + if (pfn !=3D -1UL) + memblk_nr_poison_sub(pfn, i); } =20 /* @@ -2414,6 +2417,10 @@ int unpoison_memory(unsigned long pfn) unlock_mutex: mutex_unlock(&mf_mutex); if (!ret || freeit) { + /* + * TODO: per-memory_block counter might break when the page + * size to be unpoisoned is larger than a memory_block. + */ num_poisoned_pages_sub(pfn, count); unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n", page_to_pfn(p), &unpoison_rs); @@ -2618,25 +2625,7 @@ int soft_offline_page(unsigned long pfn, int flags) return ret; } =20 -void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) +void clear_hwpoisoned_pages(long nr_poison) { - int i, total =3D 0; - - /* - * A further optimization is to have per section refcounted - * num_poisoned_pages. But that would need more space per memmap, so - * for now just do a quick global check to speed up this routine in the - * absence of bad pages. - */ - if (atomic_long_read(&num_poisoned_pages) =3D=3D 0) - return; - - for (i =3D 0; i < nr_pages; i++) { - if (PageHWPoison(&memmap[i])) { - total++; - ClearPageHWPoison(&memmap[i]); - } - } - if (total) - num_poisoned_pages_sub(total); + num_poisoned_pages_sub(-1UL, nr_poison); } diff --git a/mm/sparse.c b/mm/sparse.c index e5a8a3a0edd7..2779b419ef2a 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -926,8 +926,6 @@ void sparse_remove_section(struct mem_section *ms, unsi= gned long pfn, unsigned long nr_pages, unsigned long map_offset, struct vmem_altmap *altmap) { - clear_hwpoisoned_pages(pfn_to_page(pfn) + map_offset, - nr_pages - map_offset); section_deactivate(pfn, nr_pages, altmap); } #endif /* CONFIG_MEMORY_HOTPLUG */ --=20 2.25.1