lkml.org 
[lkml]   [2020]   [Sep]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject回复: [PATCH v3] debugobjects: install CPU ho tplug callback
Date


________________________________________
发件人: Waiman Long <longman@redhat.com>
发送时间: 2020年9月9日 2:23
收件人: Zhang, Qiang; tglx@linutronix.de; mingo@kernel.org; elver@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.zhang@windriver.com wrote:
> 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.
>
> 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 .

> +
> + return 0;
> +}
> +#endif
> +
> /*
> * We run out of memory. That means we probably have tons of objects
> * allocated.
> @@ -1367,6 +1386,11 @@ 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.


\
 
 \ /
  Last update: 2020-09-10 04:05    [W:0.119 / U:0.248 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site