hulk inclusion category: bugfix bugzilla: NA CVE: NA
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If system has many cpus (e.g. 128), it will spend a lot of time to print message to the console when execute echo q > /proc/sysrq-trigger. When /proc/sys/kernel/numa_balancing is enabled, if the migration threads is woke up, the thread cannot continue until the print finish, it will trigger a soft lockup.
PID: 619 TASK: ffffa02fdd8bec80 CPU: 121 COMMAND: "migration/121" #0 [ffff00000a103b10] __crash_kexec at ffff0000081bf200 #1 [ffff00000a103ca0] panic at ffff0000080ec93c #2 [ffff00000a103d80] watchdog_timer_fn at ffff0000081f8a14 #3 [ffff00000a103e00] __run_hrtimer at ffff00000819701c #4 [ffff00000a103e40] __hrtimer_run_queues at ffff000008197420 #5 [ffff00000a103ea0] hrtimer_interrupt at ffff00000819831c #6 [ffff00000a103f10] arch_timer_dying_cpu at ffff000008b53144 #7 [ffff00000a103f30] handle_percpu_devid_irq at ffff000008174e34 #8 [ffff00000a103f70] generic_handle_irq at ffff00000816c5e8 #9 [ffff00000a103f90] __handle_domain_irq at ffff00000816d1f4 #10 [ffff00000a103fd0] gic_handle_irq at ffff000008081860 --- <IRQ stack> --- #11 [ffff00000d6e3d50] el1_irq at ffff0000080834c8 #12 [ffff00000d6e3d60] multi_cpu_stop at ffff0000081d9964 #13 [ffff00000d6e3db0] cpu_stopper_thread at ffff0000081d9cfc #14 [ffff00000d6e3e10] smpboot_thread_fn at ffff00000811e0a8 #15 [ffff00000d6e3e70] kthread at ffff000008118988
To avoid this soft lockup, add touch_all_softlockup_watchdogs() in sysrq_timer_list_show()
Signed-off-by: Yang Yingliang yangyingliang@huawei.com Reviewed-By: Xie XiuQi xiexiuqi@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- kernel/time/timer_list.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index 07afcfe..3e74918 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -294,13 +294,17 @@ void sysrq_timer_list_show(void)
timer_list_header(NULL, now);
- for_each_online_cpu(cpu) + for_each_online_cpu(cpu) { + touch_all_softlockup_watchdogs(); print_cpu(NULL, cpu, now); + }
#ifdef CONFIG_GENERIC_CLOCKEVENTS timer_list_show_tickdevices_header(NULL); - for_each_online_cpu(cpu) + for_each_online_cpu(cpu) { + touch_all_softlockup_watchdogs(); print_tickdevice(NULL, tick_get_device(cpu), cpu); + } #endif return; }