From 76af6a054da4055305ddb28c5eb151b9ee4f74f9 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Mon, 18 Oct 2021 15:15:32 -0700 Subject: [PATCH] mm/migrate: add CPU hotplug to demotion #ifdef Once upon a time, the node demotion updates were driven solely by memory hotplug events. But now, there are handlers for both CPU and memory hotplug. However, the #ifdef around the code checks only memory hotplug. A system that has HOTPLUG_CPU=y but MEMORY_HOTPLUG=n would miss CPU hotplug events. Update the #ifdef around the common code. Add memory and CPU-specific #ifdefs for their handlers. These memory/CPU #ifdefs avoid unused function warnings when their Kconfig option is off. [arnd@arndb.de: rework hotplug_memory_notifier() stub] Link: https://lkml.kernel.org/r/20211013144029.2154629-1-arnd@kernel.org Link: https://lkml.kernel.org/r/20210924161255.E5FE8F7E@davehans-spike.ostc.intel.com Fixes: 884a6e5d1f93 ("mm/migrate: update node demotion order on hotplug events") Signed-off-by: Dave Hansen Signed-off-by: Arnd Bergmann Cc: "Huang, Ying" Cc: Michal Hocko Cc: Wei Xu Cc: Oscar Salvador Cc: David Rientjes Cc: Dan Williams Cc: David Hildenbrand Cc: Greg Thelen Cc: Yang Shi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memory.h | 5 ++++- mm/migrate.c | 42 +++++++++++++++++++++--------------------- mm/page_ext.c | 4 +--- mm/slab.c | 4 ++-- 4 files changed, 28 insertions(+), 27 deletions(-) diff --git a/include/linux/memory.h b/include/linux/memory.h index 7efc0a7..182c606 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -160,7 +160,10 @@ int walk_dynamic_memory_groups(int nid, walk_memory_groups_func_t func, #define register_hotmemory_notifier(nb) register_memory_notifier(nb) #define unregister_hotmemory_notifier(nb) unregister_memory_notifier(nb) #else -#define hotplug_memory_notifier(fn, pri) ({ 0; }) +static inline int hotplug_memory_notifier(notifier_fn_t fn, int pri) +{ + return 0; +} /* These aren't inline functions due to a GCC bug. */ #define register_hotmemory_notifier(nb) ({ (void)(nb); 0; }) #define unregister_hotmemory_notifier(nb) ({ (void)(nb); }) diff --git a/mm/migrate.c b/mm/migrate.c index a6311e4..700112c 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -3066,7 +3066,7 @@ void migrate_vma_finalize(struct migrate_vma *migrate) EXPORT_SYMBOL(migrate_vma_finalize); #endif /* CONFIG_DEVICE_PRIVATE */ -#if defined(CONFIG_MEMORY_HOTPLUG) +#if defined(CONFIG_HOTPLUG_CPU) /* Disable reclaim-based migration. */ static void __disable_all_migrate_targets(void) { @@ -3209,25 +3209,6 @@ static void set_migration_target_nodes(void) } /* - * React to hotplug events that might affect the migration targets - * like events that online or offline NUMA nodes. - * - * The ordering is also currently dependent on which nodes have - * CPUs. That means we need CPU on/offline notification too. - */ -static int migration_online_cpu(unsigned int cpu) -{ - set_migration_target_nodes(); - return 0; -} - -static int migration_offline_cpu(unsigned int cpu) -{ - set_migration_target_nodes(); - return 0; -} - -/* * This leaves migrate-on-reclaim transiently disabled between * the MEM_GOING_OFFLINE and MEM_OFFLINE events. This runs * whether reclaim-based migration is enabled or not, which @@ -3284,6 +3265,25 @@ static int __meminit migrate_on_reclaim_callback(struct notifier_block *self, return notifier_from_errno(0); } +/* + * React to hotplug events that might affect the migration targets + * like events that online or offline NUMA nodes. + * + * The ordering is also currently dependent on which nodes have + * CPUs. That means we need CPU on/offline notification too. + */ +static int migration_online_cpu(unsigned int cpu) +{ + set_migration_target_nodes(); + return 0; +} + +static int migration_offline_cpu(unsigned int cpu) +{ + set_migration_target_nodes(); + return 0; +} + static int __init migrate_on_reclaim_init(void) { int ret; @@ -3303,4 +3303,4 @@ static int __init migrate_on_reclaim_init(void) return 0; } late_initcall(migrate_on_reclaim_init); -#endif /* CONFIG_MEMORY_HOTPLUG */ +#endif /* CONFIG_HOTPLUG_CPU */ diff --git a/mm/page_ext.c b/mm/page_ext.c index dfb9165..2a52fd9 100644 --- a/mm/page_ext.c +++ b/mm/page_ext.c @@ -269,7 +269,7 @@ static int __meminit init_section_page_ext(unsigned long pfn, int nid) total_usage += table_size; return 0; } -#ifdef CONFIG_MEMORY_HOTPLUG + static void free_page_ext(void *addr) { if (is_vmalloc_addr(addr)) { @@ -374,8 +374,6 @@ static int __meminit page_ext_callback(struct notifier_block *self, return notifier_from_errno(ret); } -#endif - void __init page_ext_init(void) { unsigned long pfn; diff --git a/mm/slab.c b/mm/slab.c index d0f7256..874b3f8 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -1095,7 +1095,7 @@ static int slab_offline_cpu(unsigned int cpu) return 0; } -#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) +#if defined(CONFIG_NUMA) /* * Drains freelist for a node on each slab cache, used for memory hot-remove. * Returns -EBUSY if all objects cannot be drained so that the node is not @@ -1157,7 +1157,7 @@ static int __meminit slab_memory_callback(struct notifier_block *self, out: return notifier_from_errno(ret); } -#endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */ +#endif /* CONFIG_NUMA */ /* * swap the static kmem_cache_node with kmalloced memory -- 2.7.4