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| author | Zqiang <qiang.zhang@windriver.com> | 2020-09-08 14:27:09 +0800 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-10-01 16:13:54 +0200 |
| commit | 88451f2cd3cec2abc30debdf129422d2699d1eba (patch) | |
| tree | adde4c22e62edfd77bbbc8bee9579a37d75fa849 | |
| parent | f9e62f318fd706a54b7ce9b28e5c7e49bbde8788 (diff) | |
| download | lwn-88451f2cd3cec2abc30debdf129422d2699d1eba.tar.gz lwn-88451f2cd3cec2abc30debdf129422d2699d1eba.zip | |
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 <qiang.zhang@windriver.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20200908062709.11441-1-qiang.zhang@windriver.com
| -rw-r--r-- | include/linux/cpuhotplug.h | 1 | ||||
| -rw-r--r-- | lib/debugobjects.c | 25 |
2 files changed, 26 insertions, 0 deletions
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index bf9181cef444..6f524bbf71a2 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -36,6 +36,7 @@ enum cpuhp_state { CPUHP_X86_MCE_DEAD, CPUHP_VIRT_NET_DEAD, CPUHP_SLUB_DEAD, + CPUHP_DEBUG_OBJ_DEAD, CPUHP_MM_WRITEBACK_DEAD, CPUHP_MM_VMSTAT_DEAD, CPUHP_SOFTIRQ_DEAD, 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 <linux/slab.h> #include <linux/hash.h> #include <linux/kmemleak.h> +#include <linux/cpu.h> #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. |