From: Seiji Aguchi <seiji.aguchi@hds.com>
To: Seiji Aguchi <seiji.aguchi@hds.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>,
"rostedt@goodmis.org" <rostedt@goodmis.org>,
"hpa@zytor.com" <hpa@zytor.com>
Cc: "mingo@elte.hu" <mingo@elte.hu>,
"tglx@linutronix.de" <tglx@linutronix.de>,
Fengguang Wu <fengguang.wu@intel.com>
Subject: RE: [PATCH -tip] x86,trace: Add rcu_irq_enter/exit() in smp_trace_reschedule_interrupt()
Date: Fri, 28 Jun 2013 14:01:46 +0000 [thread overview]
Message-ID: <A5ED84D3BB3A384992CBB9C77DEDA4D443E0FBE2@USINDEM103.corp.hds.com> (raw)
In-Reply-To: <51C8AA31.3070208@hds.com>
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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 <seiji.aguchi@hds.com>
> ---
> 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
>
> --
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next prev parent reply other threads:[~2013-06-28 14:02 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-24 20:21 [PATCH -tip] x86,trace: Add rcu_irq_enter/exit() in smp_trace_reschedule_interrupt() Seiji Aguchi
2013-06-28 14:01 ` Seiji Aguchi [this message]
2013-06-28 14:21 ` Steven Rostedt
2013-06-28 15:13 ` Seiji Aguchi
2013-06-28 15:36 ` Steven Rostedt
2013-06-28 15:48 ` Seiji Aguchi
2013-06-28 15:19 ` Peter Zijlstra
2013-06-28 15:37 ` Steven Rostedt
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