There seems another build error in aarch64 with MEMORY_HOTPLUG disabled. https://lore.kernel.org/lkml/20220923110144.GA1413812@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ , so let me revise this patch again to handle it. - Naoya Horiguchi --- From: Naoya Horiguchi <naoya.horiguchi@xxxxxxx> Date: Fri, 23 Sep 2022 22:51:20 +0900 Subject: [PATCH v5 4/4] mm/hwpoison: introduce per-memory_block hwpoison counter 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 <naoya.horiguchi@xxxxxxx> Reported-by: kernel test robot <lkp@xxxxxxxxx> --- 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@xxxxxxxxx/) by using memblk_nr_poison() to access to the member ->nr_hwpoison --- drivers/base/memory.c | 34 ++++++++++++++++++++++++++++++++++ include/linux/memory.h | 3 +++ include/linux/mm.h | 24 ++++++++++++++++++++++++ mm/internal.h | 8 -------- mm/memory-failure.c | 31 ++++++++++--------------------- mm/sparse.c | 2 -- 6 files changed, 71 insertions(+), 31 deletions(-) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 9aa0da991cfb..99e0e789616c 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; + if (memblk_nr_poison(start_pfn)) + return -EHWPOISON; + zone = zone_for_pfn_range(mem->online_type, mem->nid, mem->group, start_pfn, nr_pages); @@ -864,6 +867,7 @@ 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; + clear_hwpoisoned_pages(memblk_nr_poison(start)); unregister_memory_block_under_nodes(mem); remove_memory_block(mem); } @@ -1164,3 +1168,33 @@ 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); +} + +unsigned long memblk_nr_poison(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) + return atomic_long_read(&mem->nr_hwpoison); + return 0; +} +#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 2bb5d1596041..936864d6f8be 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); #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 clear_hwpoisoned_pages(long nr_poison); #else static inline int __get_huge_page_for_hwpoison(unsigned long pfn, int flags) { @@ -3289,6 +3290,29 @@ static inline int __get_huge_page_for_hwpoison(unsigned long pfn, int flags) static inline void num_poisoned_pages_inc(unsigned long pfn) { } + +static inline void clear_hwpoisoned_pages(long nr_poison) +{ +} +#endif + +#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG) +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); +#else +static inline void memblk_nr_poison_inc(unsigned long pfn) +{ +} + +static inline void memblk_nr_poison_sub(unsigned long pfn, long i) +{ +} + +static inline unsigned long memblk_nr_poison(unsigned long pfn) +{ + return 0; +} #endif #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; -#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_pages) -{ -} -#endif - extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long, 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 = ATOMIC_LONG_INIT(0); static bool hw_memory_failure __read_mostly = false; -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); } static inline void num_poisoned_pages_sub(unsigned long pfn, long i) { atomic_long_sub(i, &num_poisoned_pages); + if (pfn != -1UL) + memblk_nr_poison_sub(pfn, i); } /* @@ -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; } -void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) +void clear_hwpoisoned_pages(long nr_poison) { - int i, total = 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) == 0) - return; - - for (i = 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, unsigned 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 */ -- 2.37.3.518.g79f2338b37
