On 2022/10/7 9:07, Naoya Horiguchi wrote: > From: Naoya Horiguchi <naoya.horiguchi@xxxxxxx> > > 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 <naoya.horiguchi@xxxxxxx> > Reported-by: kernel test robot <lkp@xxxxxxxxx> > --- > 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@xxxxxxxxx/) > 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 <linmiaohe@xxxxxxxxxx> Thanks, Miaohe Lin
