From: Zqiang <[email protected]>
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 <[email protected]>
---
v1->v2:
Modify submission information.
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
tglx please review.
Thanks
Qiang
________________________________________
??????: [email protected] <[email protected]> ???? [email protected] <[email protected]>
????ʱ??: 2020??8??27?? 13:06
?ռ???: [email protected]; [email protected]; [email protected]
????: [email protected]
????: [PATCH v2] debugobjects: install cpu hotplug callback
From: Zqiang <[email protected]>
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 <[email protected]>
---
v1->v2:
Modify submission information.
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
* Zhang, Qiang <[email protected]> wrote:
> tglx please review.
>
> Thanks
> Qiang
> ________________________________________
> 发件人: [email protected] <[email protected]> 代表 [email protected] <[email protected]>
> 发送时间: 2020年8月27日 13:06
> 收件人: [email protected]; [email protected]; [email protected]
> 抄送: [email protected]
> 主题: [PATCH v2] debugobjects: install cpu hotplug callback
>
> From: Zqiang <[email protected]>
>
> 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.
We capitalize 'CPU'. Also, please split this in at least two sentences.
>
> Signed-off-by: Zqiang <[email protected]>
> ---
> v1->v2:
> Modify submission information.
>
> 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
What happens to ->obj_free, if the CPU is brought back online? Won't it be
out of sync at that point?
> +#if defined(CONFIG_HOTPLUG_CPU)
There's a shorter preprocessor sequence for that pattern.
Thanks,
Ingo
On Fri, Sep 04 2020 at 07:50, Ingo Molnar wrote:
>> +#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
>
> What happens to ->obj_free, if the CPU is brought back online? Won't it be
> out of sync at that point?
Yes and it's going to do the completely wrong thing.
Thanks,
tglx