Hi Viresh, 0day kernel testing robot got the below dmesg and the first bad commit is git://git.linaro.org/people/vireshk/linux tick/ONESHOT-STOPPED commit d5a085970b0b88b8c82303d2c45f09c9427fd02a Author: Viresh Kumar AuthorDate: Tue Jun 10 13:52:25 2014 +0530 Commit: Viresh Kumar CommitDate: Thu Jun 19 10:35:12 2014 +0530 clockevents: x86: add support for ONESHOT_STOPPED mode Clockevent devices can be stopped from core (hrtimers/tick) when they aren't used anymore. This will mostly happen on a idle or tickless cpu. This is done to avoid getting spurious interrupts when core doesn't want to handle them anymore. For stopping clockevent devices, core requests drivers to switch to a special optional mode: CLOCK_EVT_MODE_ONESHOT_STOPPED. At this time platforms can also save some power by disabling these devices. This patch adds support for handling CLOCK_EVT_MODE_ONESHOT_STOPPED mode for x86 drivers. Signed-off-by: Viresh Kumar +-----------------------------------------------------------------+------------+------------+ | | f4f5df6f14 | d5a085970b | +-----------------------------------------------------------------+------------+------------+ | boot_successes | 120 | 9 | | boot_failures | 0 | 31 | | WARNING:CPU:PID:at_kernel/time/tick-oneshot.c:tick_stop_event() | 0 | 31 | | backtrace:cpu_startup_entry | 0 | 19 | +-----------------------------------------------------------------+------------+------------+ [ 0.247455] WARNING: CPU: 0 PID: 0 at kernel/time/tick-oneshot.c:32 tick_stop_event+0x43/0x50() [ 0.247455] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.16.0-rc1-00016-gd5a0859 #1 [ 0.247455] 0000000000000009 ffff880012203eb0 ffffffff81658a72 0000000000000000 [ 0.247455] ffff880012203ee8 ffffffff8108c128 ffff88001220ca80 7fffffffffffffff [ 0.247455] 000000000e82ddd2 7fffffffffffffff ffff8800123cd560 ffff880012203ef8 [ 0.247455] Call Trace: [ 0.247455] [] dump_stack+0x4d/0x66 [ 0.247455] [] warn_slowpath_common+0x78/0xa0 [ 0.247455] [] warn_slowpath_null+0x1a/0x20 [ 0.247455] [] tick_stop_event+0x43/0x50 [ 0.247455] [] __tick_nohz_idle_enter+0x515/0x580 [ 0.247455] [] ? tick_nohz_irq_exit+0x29/0x30 [ 0.247455] [] tick_nohz_irq_exit+0x29/0x30 [ 0.247455] [] irq_exit+0xb5/0xd0 [ 0.247455] [] smp_call_function_single_interrupt+0x35/0x40 [ 0.247455] [] call_function_single_interrupt+0x72/0x80 [ 0.247455] [] ? native_safe_halt+0x6/0x10 [ 0.247455] [] default_idle+0x24/0xe0 [ 0.247455] [] arch_cpu_idle+0xf/0x20 [ 0.247455] [] cpu_startup_entry+0x386/0x4f0 [ 0.247455] [] rest_init+0xc6/0xd0 [ 0.247455] [] ? rest_init+0x5/0xd0 [ 0.247455] [] start_kernel+0x41e/0x429 [ 0.247455] [] ? set_init_arg+0x53/0x53 [ 0.247455] [] ? early_idt_handlers+0x120/0x120 [ 0.247455] [] x86_64_start_reservations+0x2a/0x2c [ 0.247455] [] x86_64_start_kernel+0x12e/0x13d git bisect start 1ded43568e7bee60c6548e5fb3b4bd6d1d0783b1 a497c3ba1d97fc69c1e78e7b96435ba8c2cb42ee -- git bisect good 5f069b44108f255ab9a881ff366c793bc1cda5e9 # 14:27 21+ 0 Merge 'ipvs-next/master' into devel-hourly-2014062313 git bisect good 70eab242a357abfe990c30656a396f1b0a0ba465 # 14:33 21+ 0 Merge 'cifs/for-next' into devel-hourly-2014062313 git bisect good 64550da9a486e3766b85928f442756f29c39437a # 14:40 21+ 0 Merge 'rcu/rcu_cond_resched.2014.06.20c' into devel-hourly-2014062313 git bisect bad bf774a68a67dd0c0f938258f56346763d619bdbf # 14:44 0- 6 Merge 'vireshk/tick/lowres-go-tickless' into devel-hourly-2014062313 git bisect bad b1efa076fdd9532ba3fdf0bddb475ed968f33c13 # 14:50 2- 1 Merge 'vireshk/tick/ONESHOT-STOPPED' into devel-hourly-2014062313 git bisect good f935474b892829a400f31ec076385b792034a32e # 15:02 40+ 0 clockevents: Introduce CLOCK_EVT_MODE_ONESHOT_STOPPED mode git bisect good f4f5df6f142f6797c9aae44d8b570843544dcca9 # 15:12 40+ 0 clockevents: mips: add support for ONESHOT_STOPPED mode git bisect bad 2d74fb379fa8c9d388fcce15e84772713ac7331d # 15:16 5- 8 clockevents: misc: add support for ONESHOT_STOPPED mode git bisect bad 6e9ed902730ca7f5cde9fcf47c6b1ca2a143babf # 15:33 1- 14 clockevents: drivers: add support for ONESHOT_STOPPED mode git bisect bad d5a085970b0b88b8c82303d2c45f09c9427fd02a # 15:43 1- 2 clockevents: x86: add support for ONESHOT_STOPPED mode # first bad commit: [d5a085970b0b88b8c82303d2c45f09c9427fd02a] clockevents: x86: add support for ONESHOT_STOPPED mode git bisect good f4f5df6f142f6797c9aae44d8b570843544dcca9 # 15:46 120+ 0 clockevents: mips: add support for ONESHOT_STOPPED mode git bisect bad 1ded43568e7bee60c6548e5fb3b4bd6d1d0783b1 # 15:46 0- 11 0day head guard for 'devel-hourly-2014062313' git bisect good a497c3ba1d97fc69c1e78e7b96435ba8c2cb42ee # 15:49 120+ 0 Linux 3.16-rc2 git bisect good 58ae500a03a6bf68eee323c342431bfdd3f460b6 # 15:56 120+ 0 Add linux-next specific files for 20140623 This script may reproduce the error. ----------------------------------------------------------------------------- #!/bin/bash kernel=$1 initrd=yocto-minimal-i386.cgz wget --no-clobber https://github.com/fengguang/reproduce-kernel-bug/blob/master/initrd/$initrd kvm=( qemu-system-x86_64 -cpu kvm64 -enable-kvm -kernel $kernel -initrd $initrd -smp 2 -m 256M -net nic,vlan=0,macaddr=00:00:00:00:00:00,model=virtio -net user,vlan=0 -net nic,vlan=1,model=e1000 -net user,vlan=1 -boot order=nc -no-reboot -watchdog i6300esb -serial stdio -display none -monitor null ) append=( debug sched_debug apic=debug ignore_loglevel sysrq_always_enabled panic=10 prompt_ramdisk=0 earlyprintk=ttyS0,115200 console=ttyS0,115200 console=tty0 vga=normal root=/dev/ram0 rw ) "${kvm[@]}" --append "${append[*]}" ----------------------------------------------------------------------------- Thanks, Jet