* [PATCH v2] debugobjects: install cpu hotplug callback
@ 2020-08-27 5:06 qiang.zhang
2020-09-04 1:48 ` 回复: " Zhang, Qiang
0 siblings, 1 reply; 4+ messages in thread
From: qiang.zhang @ 2020-08-27 5:06 UTC (permalink / raw)
To: tglx, longman, elver; +Cc: linux-kernel
From: Zqiang <qiang.zhang@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.zhang@windriver.com>
---
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
^ permalink raw reply related [flat|nested] 4+ messages in thread
* 回复: [PATCH v2] debugobjects: install cpu hotplug callback
2020-08-27 5:06 [PATCH v2] debugobjects: install cpu hotplug callback qiang.zhang
@ 2020-09-04 1:48 ` Zhang, Qiang
2020-09-04 5:50 ` Ingo Molnar
0 siblings, 1 reply; 4+ messages in thread
From: Zhang, Qiang @ 2020-09-04 1:48 UTC (permalink / raw)
To: tglx, longman, elver, Ingo Molnar; +Cc: linux-kernel
tglx please review.
Thanks
Qiang
________________________________________
发件人: linux-kernel-owner@vger.kernel.org <linux-kernel-owner@vger.kernel.org> 代表 qiang.zhang@windriver.com <qiang.zhang@windriver.com>
发送时间: 2020年8月27日 13:06
收件人: tglx@linutronix.de; longman@redhat.com; elver@google.com
抄送: linux-kernel@vger.kernel.org
主题: [PATCH v2] debugobjects: install cpu hotplug callback
From: Zqiang <qiang.zhang@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.zhang@windriver.com>
---
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
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: 回复: [PATCH v2] debugobjects: install cpu hotplug callback
2020-09-04 1:48 ` 回复: " Zhang, Qiang
@ 2020-09-04 5:50 ` Ingo Molnar
2020-09-04 10:26 ` Thomas Gleixner
0 siblings, 1 reply; 4+ messages in thread
From: Ingo Molnar @ 2020-09-04 5:50 UTC (permalink / raw)
To: Zhang, Qiang; +Cc: tglx, longman, elver, linux-kernel
* Zhang, Qiang <Qiang.Zhang@windriver.com> wrote:
> tglx please review.
>
> Thanks
> Qiang
> ________________________________________
> 发件人: linux-kernel-owner@vger.kernel.org <linux-kernel-owner@vger.kernel.org> 代表 qiang.zhang@windriver.com <qiang.zhang@windriver.com>
> 发送时间: 2020年8月27日 13:06
> 收件人: tglx@linutronix.de; longman@redhat.com; elver@google.com
> 抄送: linux-kernel@vger.kernel.org
> 主题: [PATCH v2] debugobjects: install cpu hotplug callback
>
> From: Zqiang <qiang.zhang@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.
We capitalize 'CPU'. Also, please split this in at least two sentences.
>
> Signed-off-by: Zqiang <qiang.zhang@windriver.com>
> ---
> 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
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: 回复: [PATCH v2] debugobjects: install cpu hotplug callback
2020-09-04 5:50 ` Ingo Molnar
@ 2020-09-04 10:26 ` Thomas Gleixner
0 siblings, 0 replies; 4+ messages in thread
From: Thomas Gleixner @ 2020-09-04 10:26 UTC (permalink / raw)
To: Ingo Molnar, Zhang, Qiang; +Cc: longman, elver, linux-kernel
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
^ permalink raw reply [flat|nested] 4+ messages in thread
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2020-08-27 5:06 [PATCH v2] debugobjects: install cpu hotplug callback qiang.zhang
2020-09-04 1:48 ` 回复: " Zhang, Qiang
2020-09-04 5:50 ` Ingo Molnar
2020-09-04 10:26 ` Thomas Gleixner
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