回复: [PATCH] debugobjects: install cpu hotplug callback

From: Zhang, Qiang
Date: Tue Aug 25 2020 - 00:53:32 EST



________________________________________
发件人: linux-kernel-owner@xxxxxxxxxxxxxxx <linux-kernel-owner@xxxxxxxxxxxxxxx> 代表 qiang.zhang@xxxxxxxxxxxxx <qiang.zhang@xxxxxxxxxxxxx>
发送时间: 2020年8月20日 11:24
收件人: tglx@xxxxxxxxxxxxx; elver@xxxxxxxxxx; longman@xxxxxxxxxx
抄送: linux-kernel@xxxxxxxxxxxxxxx
主题: [PATCH] debugobjects: install cpu hotplug callback

From: Zqiang <qiang.zhang@xxxxxxxxxxxxx>

When a cpu going offline, we should free objects in "percpu_obj_pool"
free_objs list which corresponding to this cpu.

Signed-off-by: Zqiang <qiang.zhang@xxxxxxxxxxxxx>
---
include/linux/cpuhotplug.h | 1 +
lib/debugobjects.c | 23 +++++++++++++++++++++++
2 files changed, 24 insertions(+)

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index a2710e654b64..2e77db655cfa 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..50e21ed0519e 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 +434,23 @@ static void free_object(struct debug_obj *obj)
}
}

+#if defined(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);
+ }
+
+ return 0;
+}
+#endif
+
/*
* We run out of memory. That means we probably have tons of objects
* allocated.
@@ -1367,6 +1385,11 @@ void __init debug_objects_mem_init(void)
} else
debug_objects_selftest();

+#if defined(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.
--
2.17.1