From: Tang Yizhou <tangyizhou@huawei.com> ascend inclusion category: perf bugzilla: https://gitee.com/openeuler/kernel/issues/I4EUVI CVE: NA ------------------------------------------------- __sp_group_drop_locked() actually doesn't need to be protected by any locks. Signed-off-by: Tang Yizhou <tangyizhou@huawei.com> Reviewed-by: Ding Tianhong <dingtianhong@huawei.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Reviewed-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- mm/share_pool.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/mm/share_pool.c b/mm/share_pool.c index 167f990d8d9e2..16aadd3ebefa3 100644 --- a/mm/share_pool.c +++ b/mm/share_pool.c @@ -503,7 +503,7 @@ static void sp_munmap_task_areas(struct mm_struct *mm, struct list_head *stop) } /* The caller must hold sp_mutex. */ -static void __sp_group_drop_locked(struct sp_group *spg) +static void sp_group_drop(struct sp_group *spg) { if (atomic_dec_and_test(&spg->use_count)) free_sp_group(spg); @@ -732,7 +732,7 @@ int sp_group_add_task(int pid, int spg_id) out_drop_group: if (unlikely(ret)) - __sp_group_drop_locked(spg); + sp_group_drop(spg); out_put_mm: /* No need to put the mm if the sp group adds this mm successfully */ if (unlikely(ret)) @@ -781,7 +781,7 @@ void sp_group_post_exit(struct mm_struct *mm) idr_remove(&sp_stat_idr, mm->sp_stat_id); up_write(&sp_stat_sem); - __sp_group_drop_locked(spg); + sp_group_drop(spg); kfree(stat); } @@ -2922,6 +2922,7 @@ void sp_group_exit(struct mm_struct *mm) */ down_write(&spg->rw_lock); if (spg_valid(spg) && atomic_read(&mm->mm_users) == MM_WOULD_FREE) { + /* a dead group should NOT be reactive again */ if (list_is_singular(&spg->procs)) is_alive = spg->is_alive = false; list_del(&mm->sp_node); /* affect spg->procs */ -- 2.25.1