nmi: provide the option to issue an NMI back trace to every cpu but current

[cascardo/linux.git] / arch / x86 / kernel / apic / hw_nmi.c

diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c
index c3fcb5d..6a1e71b 100644 (file)
--- a/arch/x86/kernel/apic/hw_nmi.c
+++ b/arch/x86/kernel/apic/hw_nmi.c
@@ -33,31 +33,41 @@ 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)
+void arch_trigger_all_cpu_backtrace(bool include_self)
 {
        int i;
+       int cpu = get_cpu();
 
-       if (test_and_set_bit(0, &backtrace_flag))
+       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.
                 */
+               put_cpu();
                return;
+       }
 
        cpumask_copy(to_cpumask(backtrace_mask), cpu_online_mask);
+       if (!include_self)
+               cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask));
 
-       printk(KERN_INFO "sending NMI to all CPUs:\n");
-       apic->send_IPI_all(NMI_VECTOR);
+       if (!cpumask_empty(to_cpumask(backtrace_mask))) {
+               pr_info("sending NMI to %s CPUs:\n",
+                       (include_self ? "all" : "other"));
+               apic->send_IPI_mask(to_cpumask(backtrace_mask), NMI_VECTOR);
+       }
 
        /* Wait for up to 10 seconds for all CPUs to do the backtrace */
        for (i = 0; i < 10 * 1000; i++) {
                if (cpumask_empty(to_cpumask(backtrace_mask)))
                        break;
                mdelay(1);
+               touch_softlockup_watchdog();
        }
 
        clear_bit(0, &backtrace_flag);
        smp_mb__after_atomic();
+       put_cpu();
 }
 
 static int