diff options
| -rw-r--r-- | arch/x86/kernel/apic/hw_nmi.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c index 2b40a60..72ec29e 100644 --- a/arch/x86/kernel/apic/hw_nmi.c +++ b/arch/x86/kernel/apic/hw_nmi.c @@ -28,10 +28,20 @@ u64 hw_nmi_get_sample_period(void) /* For reliability, we're prepared to waste bits here. */ static DECLARE_BITMAP(backtrace_mask, NR_CPUS) __read_mostly; +/* "in progress" flag of arch_trigger_all_cpu_backtrace */ +static unsigned long backtrace_flag; + void arch_trigger_all_cpu_backtrace(void) { int i; + if (test_and_set_bit(0, &backtrace_flag)) + /* + * If there is already a trigger_all_cpu_backtrace() in progress + * (backtrace_flag == 1), don't output double cpu dump infos. + */ + return; + cpumask_copy(to_cpumask(backtrace_mask), cpu_online_mask); printk(KERN_INFO "sending NMI to all CPUs:\n"); @@ -43,6 +53,9 @@ void arch_trigger_all_cpu_backtrace(void) break; mdelay(1); } + + clear_bit(0, &backtrace_flag); + smp_mb__after_clear_bit(); } static int __kprobes |