From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755032Ab3F1OCX (ORCPT ); Fri, 28 Jun 2013 10:02:23 -0400 Received: from usindpps05.hds.com ([207.126.252.18]:50010 "EHLO usindpps05.hds.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754987Ab3F1OCV (ORCPT ); Fri, 28 Jun 2013 10:02:21 -0400 From: Seiji Aguchi To: Seiji Aguchi , "linux-kernel@vger.kernel.org" , "x86@kernel.org" , "rostedt@goodmis.org" , "hpa@zytor.com" CC: "mingo@elte.hu" , "tglx@linutronix.de" , Fengguang Wu Subject: RE: [PATCH -tip] x86,trace: Add rcu_irq_enter/exit() in smp_trace_reschedule_interrupt() Thread-Topic: [PATCH -tip] x86,trace: Add rcu_irq_enter/exit() in smp_trace_reschedule_interrupt() Thread-Index: AQHOcRh6tLsjeasi80i72tgopT7X3plLLckg Date: Fri, 28 Jun 2013 14:01:46 +0000 Message-ID: References: <51C8AA31.3070208@hds.com> In-Reply-To: <51C8AA31.3070208@hds.com> Accept-Language: ja-JP, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.74.73.11] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 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=2013-06-28_06:2013-06-28,2013-06-28,1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=outbound_policy score=0 spamscore=0 suspectscore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=7.0.1-1305240000 definitions=main-1306280082 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id r5SE2U33021321 Any comments? > -----Original Message----- > From: linux-kernel-owner@vger.kernel.org [mailto:linux-kernel-owner@vger.kernel.org] On Behalf Of Seiji Aguchi > Sent: Monday, June 24, 2013 4:21 PM > 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() > > 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 > > -- > 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/ {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I