Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756735Ab3HZO6s (ORCPT ); Mon, 26 Aug 2013 10:58:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:27311 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752002Ab3HZO6r (ORCPT ); Mon, 26 Aug 2013 10:58:47 -0400 Date: Mon, 26 Aug 2013 10:58:38 -0400 From: Dave Jones To: Linux Kernel Cc: Paul McKenney Subject: suspicious RCU usage (perf) Message-ID: <20130826145838.GA8377@redhat.com> Mail-Followup-To: Dave Jones , Linux Kernel , Paul McKenney MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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 Content-Length: 3404 Lines: 55 Another day, another rcu backtrace.. This says rc6, but it's pretty darn close to rc7, I think it was running a build from Friday. [260431.854524] =============================== [260431.855485] [ INFO: suspicious RCU usage. ] [260431.856437] 3.11.0-rc6+ #12 Not tainted [260431.857377] ------------------------------- [260431.858318] include/linux/rcupdate.h:779 rcu_read_lock() used illegally while idle! [260431.859278] other info that might help us debug this: [260431.862144] RCU used illegally from idle CPU! rcu_scheduler_active = 1, debug_locks = 0 [260431.864990] RCU used illegally from extended quiescent state! [260431.865949] 1 lock held by trinity-kid3/15917: [260431.866901] #0: (rcu_read_lock){.+.+..}, at: [] __perf_event_overflow+0x100/0x320 [260431.867896] stack backtrace: [260431.869815] CPU: 0 PID: 15917 Comm: trinity-kid3 Not tainted 3.11.0-rc6+ #12 [260431.871885] 0000000000000000 ffff8801095d3ad0 ffffffff816f9c6f ffff88023ce86950 [260431.872912] ffff8801095d3b00 ffffffff810be6a7 ffff880079695cd0 0000000000000000 [260431.873910] ffff8801095d3c00 0000000000000000 ffff8801095d3b80 ffffffff81146ef4 [260431.874909] Call Trace: [260431.875883] [] dump_stack+0x54/0x74 [260431.876869] [] lockdep_rcu_suspicious+0xe7/0x120 [260431.877852] [] __perf_event_overflow+0x2a4/0x320 [260431.878834] [] ? __perf_event_overflow+0x100/0x320 [260431.879811] [] ? __perf_event_overflow+0x1bc/0x320 [260431.880784] [] ? ftrace_call+0x5/0x2f [260431.881758] [] perf_swevent_overflow+0x51/0xe0 [260431.882728] [] perf_swevent_event+0x5f/0x90 [260431.883685] [] perf_tp_event+0x109/0x4f0 [260431.884637] [] ? perf_tp_event+0x322/0x4f0 [260431.885586] [] ? rcu_eqs_enter_common+0x5b/0x420 [260431.886539] [] ? task_work_run+0xe0/0xe0 [260431.887486] [] perf_ftrace_function_call+0xc0/0xd0 [260431.888417] [] ? ftrace_ops_control_func+0xe7/0x110 [260431.889353] [] ? task_work_run+0xe0/0xe0 [260431.890281] [] ? rcu_eqs_enter_common+0x5b/0x420 [260431.891191] [] ftrace_ops_control_func+0xe7/0x110 [260431.892088] [] ftrace_call+0x5/0x2f [260431.892975] [] ? ftrace_ops_control_func+0x6b/0x110 [260431.893862] [] ? ftrace_call+0x5/0x2f [260431.894745] [] ? local_clock+0x3f/0x50 [260431.895631] [] ? debug_lockdep_rcu_enabled+0x5/0x40 [260431.896516] [] ? debug_lockdep_rcu_enabled+0x5/0x40 [260431.897387] [] ? rcu_eqs_enter_common+0x5b/0x420 [260431.898264] [] rcu_eqs_enter+0x64/0xa0 [260431.899133] [] rcu_user_enter+0x13/0x20 [260431.899999] [] user_enter+0x6a/0xd0 [260431.900859] [] syscall_trace_leave+0x78/0x150 [260431.901712] [] int_check_syscall_exit_work+0x34/0x3d -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/