From a3b9e191f5fc11fa93176a4074a919d33d64c5fe Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 7 Oct 2024 18:50:10 +0200 Subject: [PATCH] debugobjects: Rework object freeing __free_object() is uncomprehensibly complex. The same can be achieved by: 1) Adding the object to the per CPU pool 2) If that pool is full, move a batch of objects into the global pool or if the global pool is full into the to free pool This also prepares for batch processing. Signed-off-by: Thomas Gleixner Reviewed-by: Zhen Lei Link: https://lore.kernel.org/all/20241007164913.955542307@linutronix.de --- lib/debugobjects.c | 99 +++++++++++----------------------------------- 1 file changed, 24 insertions(+), 75 deletions(-) diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 3b18d5dcbf6e..3700ddfcf76a 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -199,6 +199,27 @@ static struct debug_obj *pcpu_alloc(void) } } +static void pcpu_free(struct debug_obj *obj) +{ + struct obj_pool *pcp = this_cpu_ptr(&pool_pcpu); + + lockdep_assert_irqs_disabled(); + + hlist_add_head(&obj->node, &pcp->objects); + pcp->cnt++; + + /* Pool full ? */ + if (pcp->cnt < ODEBUG_POOL_PERCPU_SIZE) + return; + + /* Remove a batch from the per CPU pool */ + guard(raw_spinlock)(&pool_lock); + /* Try to fit the batch into the pool_global first */ + if (!pool_move_batch(&pool_global, pcp)) + pool_move_batch(&pool_to_free, pcp); + obj_pool_used -= ODEBUG_BATCH_SIZE; +} + static void free_object_list(struct hlist_head *head) { struct hlist_node *tmp; @@ -375,83 +396,11 @@ static void free_obj_work(struct work_struct *work) static void __free_object(struct debug_obj *obj) { - struct debug_obj *objs[ODEBUG_BATCH_SIZE]; - struct obj_pool *percpu_pool; - int lookahead_count = 0; - bool work; - guard(irqsave)(); - - if (unlikely(!obj_cache)) { + if (likely(obj_cache)) + pcpu_free(obj); + else hlist_add_head(&obj->node, &pool_boot); - return; - } - - /* - * Try to free it into the percpu pool first. - */ - 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; - } - - /* - * As the percpu pool is full, look ahead and pull out a batch - * 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->objects); - if (!objs[lookahead_count]) - break; - percpu_pool->cnt--; - } - - raw_spin_lock(&pool_lock); - work = (pool_global.cnt > pool_global.max_cnt) && obj_cache && - (pool_to_free.cnt < ODEBUG_FREE_WORK_MAX); - obj_pool_used--; - - if (work) { - WRITE_ONCE(pool_to_free.cnt, pool_to_free.cnt + 1); - hlist_add_head(&obj->node, &pool_to_free.objects); - if (lookahead_count) { - WRITE_ONCE(pool_to_free.cnt, pool_to_free.cnt + lookahead_count); - obj_pool_used -= lookahead_count; - while (lookahead_count) { - hlist_add_head(&objs[--lookahead_count]->node, - &pool_to_free.objects); - } - } - - if ((pool_global.cnt > pool_global.max_cnt) && - (pool_to_free.cnt < ODEBUG_FREE_WORK_MAX)) { - int i; - - /* - * Free one more batch of objects from obj_pool. - */ - for (i = 0; i < ODEBUG_BATCH_SIZE; i++) { - obj = __alloc_object(&pool_global.objects); - hlist_add_head(&obj->node, &pool_to_free.objects); - WRITE_ONCE(pool_global.cnt, pool_global.cnt - 1); - WRITE_ONCE(pool_to_free.cnt, pool_to_free.cnt + 1); - } - } - } else { - WRITE_ONCE(pool_global.cnt, pool_global.cnt + 1); - hlist_add_head(&obj->node, &pool_global.objects); - if (lookahead_count) { - WRITE_ONCE(pool_global.cnt, pool_global.cnt + lookahead_count); - obj_pool_used -= lookahead_count; - while (lookahead_count) { - hlist_add_head(&objs[--lookahead_count]->node, - &pool_global.objects); - } - } - } - raw_spin_unlock(&pool_lock); } /*