diff --git a/mm/share_pool.c b/mm/share_pool.c index 40147ef85ba5d518d14f69ef94af4f0bd6c52284..f33b4b308dcf23e7d39e437b394d4aaa97969970 100644 --- a/mm/share_pool.c +++ b/mm/share_pool.c @@ -4118,7 +4118,6 @@ static int idr_proc_stat_cb(int id, void *p, void *data) long sp_res, sp_res_nsize, non_sp_res, non_sp_shm; /* to prevent ABBA deadlock, first hold sp_group_sem */ - down_read(&sp_group_sem); mutex_lock(&spg_stat->lock); hash_for_each(spg_stat->hash, i, spg_proc_stat, gnode) { proc_stat = spg_proc_stat->proc_stat; @@ -4147,7 +4146,6 @@ static int idr_proc_stat_cb(int id, void *p, void *data) seq_putc(seq, '\n'); } mutex_unlock(&spg_stat->lock); - up_read(&sp_group_sem); return 0; } @@ -4165,10 +4163,16 @@ static int proc_stat_show(struct seq_file *seq, void *offset) byte2kb(atomic64_read(&kthread_stat.alloc_size)), byte2kb(atomic64_read(&kthread_stat.k2u_size))); - /* pay attention to potential ABBA deadlock */ + /* + * This ugly code is just for fixing the ABBA deadlock against + * sp_group_add_task. + */ + down_read(&sp_group_sem); down_read(&sp_spg_stat_sem); idr_for_each(&sp_spg_stat_idr, idr_proc_stat_cb, seq); up_read(&sp_spg_stat_sem); + up_read(&sp_group_sem); + return 0; }