The following commit has been merged into the core/debugobjects branch of tip:
Commit-ID: 88451f2cd3cec2abc30debdf129422d2699d1eba
Gitweb: https://git.kernel.org/tip/88451f2cd3cec2abc30debdf129422d2699d1eba
Author: Zqiang <qiang.zhang@xxxxxxxxxxxxx>
AuthorDate: Tue, 08 Sep 2020 14:27:09 +08:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Thu, 01 Oct 2020 16:13:54 +02:00
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@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Waiman Long <longman@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200908062709.11441-1-qiang.zhang@xxxxxxxxxxxxx
---
include/linux/cpuhotplug.h | 1 +
lib/debugobjects.c | 25 +++++++++++++++++++++++++
2 files changed, 26 insertions(+)
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index bf9181c..6f524bb 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 e2a3171..9e14ae0 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.
|