On 9/9/20 9:48 PM, Zhang, Qiang wrote:
________________________________________
发件人: Waiman Long <long...@redhat.com>
发送时间: 2020年9月9日 2:23
收件人: Zhang, Qiang; t...@linutronix.de; mi...@kernel.org; el...@google.com
抄送: linux-kernel@vger.kernel.org
主题: Re: [PATCH v3] debugobjects: install CPU hotplug callback
On 9/8/20 2:27 AM, qiang.zh...@windriver.com wrote:
From: Zqiang <qiang.zh...@windriver.com>
Due to CPU hotplug, it may never be online after it's offline,
some objects in percpu pool is never free. in order to avoid
this happening, install CPU hotplug callback, call this callback
func to free objects in percpu pool when CPU going offline.
Signed-off-by: Zqiang <qiang.zh...@windriver.com>
---
v1->v2:
Modify submission information.
v2->v3:
In CPU hotplug callback func, add clear percpu pool "obj_free" operation.
capitalize 'CPU', and use shorter preprocessor sequence.
include/linux/cpuhotplug.h | 1 +
lib/debugobjects.c | 24 ++++++++++++++++++++++++
2 files changed, 25 insertions(+)
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 3215023d4852..0c39d57e5342 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 fe4557955d97..bb69a02c3e7b 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 +434,24 @@ 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;
+
+ 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;
For pointer, it is better to use NULL for clarity.
Cheers,
Longman
Do you mean "->obj_free" variable ? this represents the number of free
objects in percpu_pool .
You are right. I got confused. Sorry for the noise.
Cheers,
Longman
