On 2022/9/23 22:12, Naoya Horiguchi wrote: > 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> LGTM with some nits below. Thanks. Reviewed-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> > --- > 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)); clear_hwpoisoned_pages seems not a proper name now? PageHWPoison info is kept now. But this should be trivial. > 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) memblk_nr_poison() is only used inside this file. Make it static? Thanks, Miaohe Lin
