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 <dave.hansen@linux.intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 @@
#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 @@
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 @@
}
/*
- * 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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
out:
return notifier_from_errno(ret);
}
-#endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */
+#endif /* CONFIG_NUMA */
/*
* swap the static kmem_cache_node with kmalloced memory
