Any comments?
> -----Original Message----- > From: linux-kernel-ow...@vger.kernel.org > [mailto:linux-kernel-ow...@vger.kernel.org] On Behalf Of Seiji Aguchi > Sent: Monday, June 24, 2013 4:21 PM > To: linux-kernel@vger.kernel.org; x...@kernel.org; rost...@goodmis.org; > h...@zytor.com > Cc: mi...@elte.hu; t...@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.agu...@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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
