Re: [patch 13/25] debugobjects: Rename and tidy up per CPU pools

From: Leizhen (ThunderTown)
Date: Thu Oct 10 2024 - 02:23:46 EST




On 2024/10/8 0:50, Thomas Gleixner wrote:
> No point in having a separate data structure. Reuse struct obj_pool and
> tidy up the code.

Reviewed-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>

>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> ---
> lib/debugobjects.c | 43 +++++++++++++++++--------------------------
> 1 file changed, 17 insertions(+), 26 deletions(-)
>
> --- a/lib/debugobjects.c
> +++ b/lib/debugobjects.c
> @@ -43,21 +43,12 @@ struct debug_bucket {
> raw_spinlock_t lock;
> };
>
> -/*
> - * Debug object percpu free list
> - * Access is protected by disabling irq
> - */
> -struct debug_percpu_free {
> - struct hlist_head free_objs;
> - int obj_free;
> -};
> -
> struct obj_pool {
> struct hlist_head objects;
> unsigned int cnt;
> } ____cacheline_aligned;
>
> -static DEFINE_PER_CPU(struct debug_percpu_free, percpu_obj_pool);
> +static DEFINE_PER_CPU(struct obj_pool, pool_pcpu);
>
> static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE];
>
> @@ -271,13 +262,13 @@ static struct debug_obj *__alloc_object(
> static struct debug_obj *
> alloc_object(void *addr, struct debug_bucket *b, const struct debug_obj_descr *descr)
> {
> - struct debug_percpu_free *percpu_pool = this_cpu_ptr(&percpu_obj_pool);
> + struct obj_pool *percpu_pool = this_cpu_ptr(&pool_pcpu);
> struct debug_obj *obj;
>
> if (likely(obj_cache)) {
> - obj = __alloc_object(&percpu_pool->free_objs);
> + obj = __alloc_object(&percpu_pool->objects);
> if (obj) {
> - percpu_pool->obj_free--;
> + percpu_pool->cnt--;
> goto init_obj;
> }
> } else {
> @@ -304,8 +295,8 @@ alloc_object(void *addr, struct debug_bu
> obj2 = __alloc_object(&pool_global.objects);
> if (!obj2)
> break;
> - hlist_add_head(&obj2->node, &percpu_pool->free_objs);
> - percpu_pool->obj_free++;
> + hlist_add_head(&obj2->node, &percpu_pool->objects);
> + percpu_pool->cnt++;
> obj_pool_used++;
> WRITE_ONCE(pool_global.cnt, pool_global.cnt - 1);
> }
> @@ -384,7 +375,7 @@ static void free_obj_work(struct work_st
> static void __free_object(struct debug_obj *obj)
> {
> struct debug_obj *objs[ODEBUG_BATCH_SIZE];
> - struct debug_percpu_free *percpu_pool;
> + struct obj_pool *percpu_pool;
> int lookahead_count = 0;
> bool work;
>
> @@ -398,10 +389,10 @@ static void __free_object(struct debug_o
> /*
> * Try to free it into the percpu pool first.
> */
> - percpu_pool = this_cpu_ptr(&percpu_obj_pool);
> - if (percpu_pool->obj_free < ODEBUG_POOL_PERCPU_SIZE) {
> - hlist_add_head(&obj->node, &percpu_pool->free_objs);
> - percpu_pool->obj_free++;
> + percpu_pool = this_cpu_ptr(&pool_pcpu);
> + if (percpu_pool->cnt < ODEBUG_POOL_PERCPU_SIZE) {
> + hlist_add_head(&obj->node, &percpu_pool->objects);
> + percpu_pool->cnt++;
> return;
> }
>
> @@ -410,10 +401,10 @@ static void __free_object(struct debug_o
> * of objects from the percpu pool and free them as well.
> */
> for (; lookahead_count < ODEBUG_BATCH_SIZE; lookahead_count++) {
> - objs[lookahead_count] = __alloc_object(&percpu_pool->free_objs);
> + objs[lookahead_count] = __alloc_object(&percpu_pool->objects);
> if (!objs[lookahead_count])
> break;
> - percpu_pool->obj_free--;
> + percpu_pool->cnt--;
> }
>
> raw_spin_lock(&pool_lock);
> @@ -494,10 +485,10 @@ static void put_objects(struct hlist_hea
> static int object_cpu_offline(unsigned int cpu)
> {
> /* Remote access is safe as the CPU is dead already */
> - struct debug_percpu_free *pcp = per_cpu_ptr(&percpu_obj_pool, cpu);
> + struct obj_pool *pcp = per_cpu_ptr(&pool_pcpu, cpu);
>
> - put_objects(&pcp->free_objs);
> - pcp->obj_free = 0;
> + put_objects(&pcp->objects);
> + pcp->cnt = 0;
> return 0;
> }
> #endif
> @@ -1076,7 +1067,7 @@ static int debug_stats_show(struct seq_f
> int cpu, obj_percpu_free = 0;
>
> for_each_possible_cpu(cpu)
> - obj_percpu_free += per_cpu(percpu_obj_pool.obj_free, cpu);
> + obj_percpu_free += per_cpu(pool_pcpu.cnt, cpu);
>
> seq_printf(m, "max_chain :%d\n", debug_objects_maxchain);
> seq_printf(m, "max_checked :%d\n", debug_objects_maxchecked);
>
> .
>

--
Regards,
Zhen Lei