2022-06-11 13:45:39

by wuchi

Subject: [PATCH] lib/debugobjects: Fix stat count and optimize debug_objects_mem_init.

1. Var debug_objects_allocated tracks valid kmem_cache_alloc calls, so
track it in debug_objects_replace_static_objects. Do similar things in
object_cpu_offline.

2. In debug_objects_mem_init, there is no need to call function
cpuhp_setup_state_nocalls when debug_objects_enabled = 0 (out of memory).

Signed-off-by: wuchi <[email protected]>
---
lib/debugobjects.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/lib/debugobjects.c b/lib/debugobjects.c
index 337d797a7141..6f8e5dd1dcd0 100644
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -437,6 +437,7 @@ static int object_cpu_offline(unsigned int cpu)
struct debug_percpu_free *percpu_pool;
struct hlist_node *tmp;
struct debug_obj *obj;
+ unsigned long flags;

/* Remote access is safe as the CPU is dead already */
percpu_pool = per_cpu_ptr(&percpu_obj_pool, cpu);
@@ -444,6 +445,12 @@ static int object_cpu_offline(unsigned int cpu)
hlist_del(&obj->node);
kmem_cache_free(obj_cache, obj);
}
+
+ raw_spin_lock_irqsave(&pool_lock, flags);
+ obj_pool_used -= percpu_pool->obj_free;
+ debug_objects_freed += percpu_pool->obj_free;
+ raw_spin_unlock_irqrestore(&pool_lock, flags);
+
percpu_pool->obj_free = 0;

return 0;
@@ -1318,6 +1325,8 @@ static int __init debug_objects_replace_static_objects(void)
hlist_add_head(&obj->node, &objects);
}

+ debug_objects_allocated += i;
+
/*
* debug_objects_mem_init() is now called early that only one CPU is up
* and interrupts have been disabled, so it is safe to replace the
@@ -1386,6 +1395,7 @@ void __init debug_objects_mem_init(void)
debug_objects_enabled = 0;
kmem_cache_destroy(obj_cache);
pr_warn("out of memory.\n");
+ return;
} else
debug_objects_selftest();

--
2.20.1

2022-07-18 00:42:17

by Andrew Morton

Subject: Re: [PATCH] lib/debugobjects: Fix stat count and optimize debug_objects_mem_init.

On Sat, 11 Jun 2022 21:06:34 +0800 wuchi <[email protected]> wrote:

> 1. Var debug_objects_allocated tracks valid kmem_cache_alloc calls, so
> track it in debug_objects_replace_static_objects. Do similar things in
> object_cpu_offline.
>
> 2. In debug_objects_mem_init, there is no need to call function
> cpuhp_setup_state_nocalls when debug_objects_enabled = 0 (out of memory).
>

Could we please have some review input here?

> --- a/lib/debugobjects.c
> +++ b/lib/debugobjects.c
> @@ -437,6 +437,7 @@ static int object_cpu_offline(unsigned int cpu)
> struct debug_percpu_free *percpu_pool;
> struct hlist_node *tmp;
> struct debug_obj *obj;
> + unsigned long flags;
>
> /* Remote access is safe as the CPU is dead already */
> percpu_pool = per_cpu_ptr(&percpu_obj_pool, cpu);
> @@ -444,6 +445,12 @@ static int object_cpu_offline(unsigned int cpu)
> hlist_del(&obj->node);
> kmem_cache_free(obj_cache, obj);
> }
> +
> + raw_spin_lock_irqsave(&pool_lock, flags);
> + obj_pool_used -= percpu_pool->obj_free;
> + debug_objects_freed += percpu_pool->obj_free;
> + raw_spin_unlock_irqrestore(&pool_lock, flags);
> +
> percpu_pool->obj_free = 0;
>
> return 0;
> @@ -1318,6 +1325,8 @@ static int __init debug_objects_replace_static_objects(void)
> hlist_add_head(&obj->node, &objects);
> }
>
> + debug_objects_allocated += i;
> +
> /*
> * debug_objects_mem_init() is now called early that only one CPU is up
> * and interrupts have been disabled, so it is safe to replace the
> @@ -1386,6 +1395,7 @@ void __init debug_objects_mem_init(void)
> debug_objects_enabled = 0;
> kmem_cache_destroy(obj_cache);
> pr_warn("out of memory.\n");
> + return;
> } else
> debug_objects_selftest();
>