Messages in this thread | | | Date | Wed, 12 Sep 2012 08:31:14 -0700 | From | "Paul E. McKenney" <> | Subject | Re: WARNING: at kernel/rcutree.c:1558 rcu_do_batch+0x386/0x3a0(), during CPU hotplug |
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On Wed, Sep 12, 2012 at 06:06:20PM +0530, Srivatsa S. Bhat wrote: > On 07/19/2012 10:45 PM, Paul E. McKenney wrote: > > On Thu, Jul 19, 2012 at 05:39:30PM +0530, Srivatsa S. Bhat wrote: > >> Hi Paul, > >> > >> While running a CPU hotplug stress test on v3.5-rc7+ > >> (mainline commit 8a7298b7805ab) I hit this warning. > >> I haven't tried to debug this yet... > >> > >> Line number 1550 maps to: > >> > >> WARN_ON_ONCE(cpu_is_offline(smp_processor_id())); > >> > >> inside rcu_do_batch(). > > > > Hello, Srivatsa, > > > > I believe that you need commit a16b7a69 (Prevent __call_rcu() from > > invoking RCU core on offline CPUs), which is currently in -tip, queued > > for 3.6. Please see below for the patch. > > > > Does this help? > > > > Hi Paul, > > I am hitting the cpu_is_offline() warning in rcu_do_batch() (see 2 of the > examples below) occasionally while testing CPU hotplug on Thomas' smp/hotplug > branch in -tip. It does contain the commit that you had mentioned above. > > The stack trace suggests that we are not hitting this from the __call_rcu() > path. So I guess this needs a different fix?
So there was an interrupt from stop_machine_stop(). Because RCU complained about offline, I presume that this was on exit from stop_machine_stop(). (Otherwise, on entry to stop_machine_stop(), the CPU has not yet marked itself offline, right?)
So my question is: Why didn't the CPU shut off all interrupts before coming out of stop_machine_stop()?
Or am I confused about what is really happening here?
Thanx, Paul
> Regards, > Srivatsa S. Bhat > > [ 53.882344] smpboot: CPU 7 is now offline > [ 53.891072] CPU 12 MCA banks CMCI:6 CMCI:8 > [ 53.895621] CPU 15 MCA banks CMCI:2 CMCI:3 CMCI:5 > [ 53.914738] Broke affinity for irq 81 > [ 53.917769] do_IRQ: 8.211 No irq handler for vector (irq -1) > [ 53.917769] ------------[ cut here ]------------ > [ 53.917769] WARNING: at kernel/rcutree.c:1558 rcu_do_batch+0x386/0x3a0() > [ 53.917769] Hardware name: IBM System x -[7870C4Q]- > [ 53.917769] Modules linked in: ipv6 cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf fuse loop dm_mod iTCO_wdt iTCO_vendor_support coretemp kvm_intel kvm cdc_ether usbnet ioatdma lpc_ich mfd_core crc32c_intel microcode mii pcspkr i2c_i801 shpchp i2c_core serio_raw bnx2 tpm_tis dca tpm pci_hotplug i7core_edac tpm_bios edac_core sg rtc_cmos button uhci_hcd ehci_hcd usbcore usb_common sd_mod crc_t10dif edd ext3 mbcache jbd fan processor mptsas mptscsih mptbase scsi_transport_sas scsi_mod thermal thermal_sys hwmon > [ 53.917769] Pid: 47, comm: migration/8 Not tainted 3.6.0-rc1-tglx-hotplug-0.0.0.28.36b5ec9-default #1 > [ 53.917769] Call Trace: > [ 53.917769] <IRQ> [<ffffffff810e7806>] ? rcu_do_batch+0x386/0x3a0 > [ 53.917769] [<ffffffff810e7806>] ? rcu_do_batch+0x386/0x3a0 > [ 53.917769] [<ffffffff8104338a>] warn_slowpath_common+0x7a/0xb0 > [ 53.917769] [<ffffffff810433d5>] warn_slowpath_null+0x15/0x20 > [ 53.917769] [<ffffffff810e7806>] rcu_do_batch+0x386/0x3a0 > [ 53.917769] [<ffffffff810ac8a0>] ? trace_hardirqs_on_caller+0x70/0x1b0 > [ 53.917769] [<ffffffff810ac9ed>] ? trace_hardirqs_on+0xd/0x10 > [ 53.917769] [<ffffffff810e9143>] __rcu_process_callbacks+0x1a3/0x200 > [ 53.917769] [<ffffffff810e9228>] rcu_process_callbacks+0x88/0x240 > [ 53.917769] [<ffffffff8104dc79>] __do_softirq+0x159/0x400 > [ 53.917769] [<ffffffff814c627c>] call_softirq+0x1c/0x30 > [ 53.917769] [<ffffffff810044f5>] do_softirq+0x95/0xd0 > [ 53.917769] [<ffffffff8104d745>] irq_exit+0xe5/0x100 > [ 53.917769] [<ffffffff81003c14>] do_IRQ+0x64/0xe0 > [ 53.917769] [<ffffffff814bc12f>] common_interrupt+0x6f/0x6f > [ 53.917769] <EOI> [<ffffffff810cfe7a>] ? stop_machine_cpu_stop+0xda/0x130 > [ 53.917769] [<ffffffff810cfda0>] ? stop_one_cpu_nowait+0x50/0x50 > [ 53.917769] [<ffffffff810cfab9>] cpu_stopper_thread+0xd9/0x1b0 > [ 53.917769] [<ffffffff814bbe4f>] ? _raw_spin_unlock_irqrestore+0x3f/0x80 > [ 53.917769] [<ffffffff810cf9e0>] ? res_counter_init+0x50/0x50 > [ 53.917769] [<ffffffff810ac95d>] ? trace_hardirqs_on_caller+0x12d/0x1b0 > [ 53.917769] [<ffffffff810ac9ed>] ? trace_hardirqs_on+0xd/0x10 > [ 53.917769] [<ffffffff810cf9e0>] ? res_counter_init+0x50/0x50 > [ 53.917769] [<ffffffff8106deae>] kthread+0xde/0xf0 > [ 53.917769] [<ffffffff814c6184>] kernel_thread_helper+0x4/0x10 > [ 53.917769] [<ffffffff814bc1f0>] ? retint_restore_args+0x13/0x13 > [ 53.917769] [<ffffffff8106ddd0>] ? __init_kthread_worker+0x70/0x70 > [ 53.917769] [<ffffffff814c6180>] ? gs_change+0x13/0x13 > [ 53.917769] ---[ end trace f60a282810c4ce78 ]--- > [ 54.170634] smpboot: CPU 8 is now offline > [ 54.192259] NOHZ: local_softirq_pending 200 > [ 54.197936] smpboot: CPU 9 is now offline > [ 54.219707] NOHZ: local_softirq_pending 200 > [ 54.225795] smpboot: CPU 10 is now offline > > > --- > > [ 372.482434] smpboot: CPU 11 is now offline > [ 372.534211] smpboot: CPU 12 is now offline > [ 372.539786] CPU 13 MCA banks CMCI:6 CMCI:8 > [ 372.582474] smpboot: CPU 13 is now offline > [ 372.591006] CPU 14 MCA banks CMCI:6 CMCI:8 > [ 372.629745] ------------[ cut here ]------------ > [ 372.633736] WARNING: at kernel/rcutree.c:1558 rcu_do_batch+0x386/0x3a0() > [ 372.633736] Hardware name: IBM System x -[7870C4Q]- > [ 372.633736] Modules linked in: ipv6 cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf fuse loop dm_mod iTCO_wdt iTCO_vendor_support coretemp kvm_intel kvm crc32c_intel > microcode serio_raw tpm_tis i7core_edac cdc_ether usbnet ioatdma mii lpc_ich pcspkr edac_core mfd_core bnx2 shpchp pci_hotplug i2c_i801 i2c_core dca tpm sg tpm_bios rtc_cmos button uhci_hcd ehci_hcd > usbcore usb_common sd_mod crc_t10dif edd ext3 mbcache jbd fan processor mptsas mptscsih mptbase scsi_transport_sas scsi_mod thermal thermal_sys hwmon > [ 372.633736] Pid: 8625, comm: migration/14 Not tainted 3.6.0-rc1-tglx-hotplug-0.0.0.28.36b5ec9-default #1 > [ 372.633736] Call Trace: > [ 372.633736] <IRQ> [<ffffffff810e7806>] ? rcu_do_batch+0x386/0x3a0 > [ 372.633736] [<ffffffff810e7806>] ? rcu_do_batch+0x386/0x3a0 > [ 372.633736] [<ffffffff8104338a>] warn_slowpath_common+0x7a/0xb0 > [ 372.633736] [<ffffffff810433d5>] warn_slowpath_null+0x15/0x20 > [ 372.633736] [<ffffffff810e7806>] rcu_do_batch+0x386/0x3a0 > [ 372.633736] [<ffffffff810ac8a0>] ? trace_hardirqs_on_caller+0x70/0x1b0 > [ 372.633736] [<ffffffff810ac9ed>] ? trace_hardirqs_on+0xd/0x10 > [ 372.633736] [<ffffffff810e9143>] __rcu_process_callbacks+0x1a3/0x200 > [ 372.633736] [<ffffffff810e9228>] rcu_process_callbacks+0x88/0x240 > [ 372.633736] [<ffffffff8104dc79>] __do_softirq+0x159/0x400 > [ 372.633736] [<ffffffff814c627c>] call_softirq+0x1c/0x30 > [ 372.633736] [<ffffffff810044f5>] do_softirq+0x95/0xd0 > [ 372.633736] [<ffffffff8104d745>] irq_exit+0xe5/0x100 > [ 372.633736] [<ffffffff81028df9>] smp_apic_timer_interrupt+0x69/0xa0 > [ 372.633736] [<ffffffff814c5aef>] apic_timer_interrupt+0x6f/0x80 > [ 372.633736] <EOI> [<ffffffff810cfe7a>] ? stop_machine_cpu_stop+0xda/0x130 > [ 372.633736] [<ffffffff810cfda0>] ? stop_one_cpu_nowait+0x50/0x50 > [ 372.633736] [<ffffffff810cfab9>] cpu_stopper_thread+0xd9/0x1b0 > [ 372.633736] [<ffffffff814bbe4f>] ? _raw_spin_unlock_irqrestore+0x3f/0x80 > [ 372.633736] [<ffffffff810cf9e0>] ? res_counter_init+0x50/0x50 > [ 372.633736] [<ffffffff810ac95d>] ? trace_hardirqs_on_caller+0x12d/0x1b0 > [ 372.633736] [<ffffffff810ac9ed>] ? trace_hardirqs_on+0xd/0x10 > [ 372.633736] [<ffffffff810cf9e0>] ? res_counter_init+0x50/0x50 > [ 372.633736] [<ffffffff8106deae>] kthread+0xde/0xf0 > [ 372.633736] [<ffffffff814c6184>] kernel_thread_helper+0x4/0x10 > [ 372.633736] [<ffffffff814bc1f0>] ? retint_restore_args+0x13/0x13 > [ 372.633736] [<ffffffff8106ddd0>] ? __init_kthread_worker+0x70/0x70 > [ 372.633736] [<ffffffff814c6180>] ? gs_change+0x13/0x13 > [ 372.633736] ---[ end trace a4296a31284c846d ]--- > [ 372.883063] smpboot: CPU 14 is now offline > [ 372.892721] CPU 15 MCA banks CMCI:6 CMCI:8 > [ 372.907250] smpboot: CPU 15 is now offline > [ 372.911545] SMP alternatives: lockdep: fixing up alternatives > [ 372.917292] SMP alternatives: switching to UP code > [ 372.941917] SMP alternatives: lockdep: fixing up alternatives > > -- > 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/ >
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