From 88451f2cd3cec2abc30debdf129422d2699d1eba Mon Sep 17 00:00:00 2001 From: Zqiang Date: Tue, 8 Sep 2020 14:27:09 +0800 Subject: debugobjects: Free per CPU pool after CPU unplug If a CPU is offlined the debug objects per CPU pool is not cleaned up. If the CPU is never onlined again then the objects in the pool are wasted. Add a CPU hotplug callback which is invoked after the CPU is dead to free the pool. [ tglx: Massaged changelog and added comment about remote access safety ] Signed-off-by: Zqiang Signed-off-by: Thomas Gleixner Cc: Waiman Long Link: https://lore.kernel.org/r/20200908062709.11441-1-qiang.zhang@windriver.com --- lib/debugobjects.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'lib/debugobjects.c') diff --git a/lib/debugobjects.c b/lib/debugobjects.c index e2a3171b6c63..9e14ae02306b 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -19,6 +19,7 @@ #include #include #include +#include #define ODEBUG_HASH_BITS 14 #define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS) @@ -433,6 +434,25 @@ static void free_object(struct debug_obj *obj) } } +#ifdef CONFIG_HOTPLUG_CPU +static int object_cpu_offline(unsigned int cpu) +{ + struct debug_percpu_free *percpu_pool; + struct hlist_node *tmp; + struct debug_obj *obj; + + /* Remote access is safe as the CPU is dead already */ + percpu_pool = per_cpu_ptr(&percpu_obj_pool, cpu); + hlist_for_each_entry_safe(obj, tmp, &percpu_pool->free_objs, node) { + hlist_del(&obj->node); + kmem_cache_free(obj_cache, obj); + } + percpu_pool->obj_free = 0; + + return 0; +} +#endif + /* * We run out of memory. That means we probably have tons of objects * allocated. @@ -1367,6 +1387,11 @@ void __init debug_objects_mem_init(void) } else debug_objects_selftest(); +#ifdef CONFIG_HOTPLUG_CPU + cpuhp_setup_state_nocalls(CPUHP_DEBUG_OBJ_DEAD, "object:offline", NULL, + object_cpu_offline); +#endif + /* * Increase the thresholds for allocating and freeing objects * according to the number of possible CPUs available in the system. -- cgit