From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753365Ab1LGHj6 (ORCPT ); Wed, 7 Dec 2011 02:39:58 -0500 Received: from mail-iy0-f174.google.com ([209.85.210.174]:57498 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753221Ab1LGHj5 (ORCPT ); Wed, 7 Dec 2011 02:39:57 -0500 Date: Wed, 7 Dec 2011 15:39:43 +0800 From: Yong Zhang To: linux-kernel@vger.kernel.org Cc: a.p.zijlstra@chello.nl, mingo@elte.hu, Suresh Siddha Subject: [BUG -tip/sched] INFO: suspicious RCU usage Message-ID: <20111207073942.GA12029@zhy> Reply-To: Yong Zhang MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org =============================== [ INFO: suspicious RCU usage. ] ------------------------------- /build/linux/kernel/sched/fair.c:5091 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 1 1 lock held by swapper/0/1: #0: (&sb->s_type->i_mutex_key#2){+.+.+.}, at: [] debugfs_create_file+0x8c/0x270 stack backtrace: Pid: 1, comm: swapper/0 Not tainted 3.2.0-rc1-00339-gcd490c5 #14 Call Trace: [] ? _raw_spin_unlock_irqrestore+0x38/0x80 [] lockdep_rcu_suspicious+0xbf/0xe0 [] trigger_load_balance+0x5b8/0x5c0 [] scheduler_tick+0x104/0x160 [] update_process_times+0x6e/0x90 [] tick_periodic+0x2c/0x70 [] tick_handle_periodic+0x24/0x80 [] ? T.562+0xf7/0x170 [] smp_apic_timer_interrupt+0x66/0x98 [] apic_timer_interrupt+0x70/0x80 [] ? lock_release+0xe4/0x2b0 [] _raw_spin_unlock+0x23/0x60 [] T.562+0xf7/0x170 [] debugfs_create_file+0xf1/0x270 [] trace_create_file+0x19/0x50 [] tracer_init_debugfs+0x2bd/0x3c0 [] ? trace_create_file+0x19/0x50 [] ? clear_boot_tracer+0x2d/0x2d [] do_one_initcall+0x43/0x180 [] kernel_init+0xd0/0x156 [] kernel_thread_helper+0x4/0x10 [] ? finish_task_switch+0x88/0xf0 [] ? _raw_spin_unlock_irq+0x3b/0x70 [] ? retint_restore_args+0xe/0xe [] ? parse_early_options+0x20/0x20 [] ? gs_change+0xb/0xb Seems due to commit [0b005cf5: sched, nohz: Implement sched group, domain aware nohz idle load balancing] Thanks, Yong