From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751234Ab3FXUVv (ORCPT ); Mon, 24 Jun 2013 16:21:51 -0400 Received: from usindpps05.hds.com ([207.126.252.18]:42750 "EHLO usindpps05.hds.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750745Ab3FXUVt (ORCPT ); Mon, 24 Jun 2013 16:21:49 -0400 Message-ID: <51C8AA31.3070208@hds.com> Date: Mon, 24 Jun 2013 16:21:05 -0400 From: Seiji Aguchi User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130509 Thunderbird/17.0.6 MIME-Version: 1.0 To: linux-kernel@vger.kernel.org, x86@kernel.org, rostedt@goodmis.org, hpa@zytor.com CC: mingo@elte.hu, tglx@linutronix.de Subject: [PATCH -tip] x86,trace: Add rcu_irq_enter/exit() in smp_trace_reschedule_interrupt() Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Proofpoint-SPF-Result: pass X-Proofpoint-SPF-Record: v=spf1 mx ip4:207.126.244.0/26 ip4:207.126.252.0/25 include:mktomail.com include:cloud.hds.com ~all X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.10.8794,1.0.431,0.0.0000 definitions=2013-06-24_05:2013-06-24,2013-06-24,1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=outbound_policy score=0 kscore.is_bulkscore=1.24827925773729e-11 kscore.compositescore=0 circleOfTrustscore=0 compositescore=0.997215366458519 urlsuspect_oldscore=0.997215366458519 suspectscore=0 recipient_domain_to_sender_totalscore=0 phishscore=0 bulkscore=0 kscore.is_spamscore=0 recipient_to_sender_totalscore=0 recipient_domain_to_sender_domain_totalscore=0 rbsscore=0.997215366458519 spamscore=0 recipient_to_sender_domain_totalscore=0 urlsuspectscore=0.9 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=7.0.1-1305240000 definitions=main-1306240197 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Reschedule vector tracepoints may be called in cpu idle state. This causes lockdep check warning below. So, add rcu_irq_enter/exit() to smp_trace_reschedule_interrupt(). [ 50.720557] Testing event reschedule_exit: [ 50.721349] [ 50.721502] =============================== [ 50.721835] [ INFO: suspicious RCU usage. ] [ 50.722169] 3.10.0-rc6-00004-gcf910e8 #190 Not tainted [ 50.722582] ------------------------------- [ 50.722915] /c/kernel-tests/src/linux/arch/x86/include/asm/trace/irq_vectors.h:50 suspicious rcu_dereference_check() usage! [ 50.723770] [ 50.723770] other info that might help us debug this: [ 50.723770] [ 50.724385] [ 50.724385] RCU used illegally from idle CPU! [ 50.724385] rcu_scheduler_active = 1, debug_locks = 0 [ 50.725232] RCU used illegally from extended quiescent state! [ 50.725690] no locks held by swapper/0/0. [ 50.726010] [ 50.726010] stack backtrace: [ 50.726359] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.10.0-rc6-00004-gcf910e8 #190 [ 50.726965] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 50.727417] 00000001 00000001 79c53f04 798bd9f9 79c53f2c 79077a70 79b412c6 79b41fd1 [ 50.728159] 00000001 00000000 79c5ef8c 87147c58 00000000 79c55800 79c53f38 79010b65 [ 50.728849] 79c52000 79c53f7c 798c720e 79c52000 79c5ef8c 00000004 00000000 79c55800 [ 50.729532] Call Trace: [ 50.729730] [<798bd9f9>] dump_stack+0x16/0x18 [ 50.730072] [<79077a70>] lockdep_rcu_suspicious+0xf2/0xfa [ 50.730498] [<79010b65>] smp_trace_reschedule_interrupt+0x1c8/0x1d0 [ 50.730979] [<798c720e>] trace_reschedule_interrupt+0x36/0x3c [ 50.731214] [<7901875f>] ? native_safe_halt+0x5/0x7 [ 50.731214] [<790085cc>] default_idle+0xb1/0x1e2 [ 50.731214] [<79008d05>] arch_cpu_idle+0xe/0x10 [ 50.731214] [<79069ddf>] cpu_startup_entry+0x1e4/0x2c3 [ 50.731214] [<798adb34>] rest_init+0x12c/0x132 [ 50.731214] [<798ada08>] ? __read_lock_failed+0x14/0x14 [ 50.731214] [<79d309e4>] start_kernel+0x38d/0x393 [ 50.731214] [<79d30489>] ? repair_env_string+0x51/0x51 [ 50.731214] [<79d302c3>] i386_start_kernel+0x79/0x7d [ 50.771947] OK [ 50.772099] Testing event reschedule_entry: OK Signed-off-by: Seiji Aguchi --- arch/x86/kernel/smp.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c index f4fe0b8..b959056 100644 --- a/arch/x86/kernel/smp.c +++ b/arch/x86/kernel/smp.c @@ -268,9 +268,11 @@ void smp_reschedule_interrupt(struct pt_regs *regs) void smp_trace_reschedule_interrupt(struct pt_regs *regs) { ack_APIC_irq(); + rcu_irq_enter(); trace_reschedule_entry(RESCHEDULE_VECTOR); __smp_reschedule_interrupt(); trace_reschedule_exit(RESCHEDULE_VECTOR); + rcu_irq_exit(); /* * KVM uses this interrupt to force a cpu out of guest mode */ -- 1.7.1