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powerpc/watchdog: provide more data in watchdog messages

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Provide timebase and timebase of last heartbeat in watchdog lockup
messages. Also provide a stack trace of when a CPU becomes un-stuck,
which can be useful -- it could be where irqs are re-enabled, so it
may be the end of the critical section which is responsible for the
latency which is useful information.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Nicholas Piggin 2018-05-05 17:26:00 +10:00 committed by Michael Ellerman
parent 5a951c4e7e
commit 4e49226ea8
1 changed files with 25 additions and 3 deletions
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28
arch/powerpc/kernel/watchdog.c
View file

@ -111,7 +111,13 @@ static inline void wd_smp_unlock(unsigned long *flags)
static void wd_lockup_ipi(struct pt_regs *regs)
{
pr_emerg("CPU %d Hard LOCKUP\n", raw_smp_processor_id());
int cpu = raw_smp_processor_id();
u64 tb = get_tb();
pr_emerg("CPU %d Hard LOCKUP\n", cpu);
pr_emerg("CPU %d TB:%lld, last heartbeat TB:%lld (%lldms ago)\n",
cpu, tb, per_cpu(wd_timer_tb, cpu),
tb_to_ns(tb - per_cpu(wd_timer_tb, cpu)) / 1000000);
print_modules();
print_irqtrace_events(current);
if (regs)
@ -154,6 +160,9 @@ static void watchdog_smp_panic(int cpu, u64 tb)
pr_emerg("CPU %d detected hard LOCKUP on other CPUs %*pbl\n",
cpu, cpumask_pr_args(&wd_smp_cpus_pending));
pr_emerg("CPU %d TB:%lld, last SMP heartbeat TB:%lld (%lldms ago)\n",
cpu, tb, wd_smp_last_reset_tb,
tb_to_ns(tb - wd_smp_last_reset_tb) / 1000000);
if (!sysctl_hardlockup_all_cpu_backtrace) {
/*
@ -194,10 +203,19 @@ static void wd_smp_clear_cpu_pending(int cpu, u64 tb)
{
if (!cpumask_test_cpu(cpu, &wd_smp_cpus_pending)) {
if (unlikely(cpumask_test_cpu(cpu, &wd_smp_cpus_stuck))) {
struct pt_regs *regs = get_irq_regs();
unsigned long flags;
pr_emerg("CPU %d became unstuck\n", cpu);
wd_smp_lock(&flags);
pr_emerg("CPU %d became unstuck TB:%lld\n",
cpu, tb);
print_irqtrace_events(current);
if (regs)
show_regs(regs);
else
dump_stack();
cpumask_clear_cpu(cpu, &wd_smp_cpus_stuck);
wd_smp_unlock(&flags);
}
@ -252,7 +270,11 @@ void soft_nmi_interrupt(struct pt_regs *regs)
}
set_cpu_stuck(cpu, tb);
pr_emerg("CPU %d self-detected hard LOCKUP @ %pS\n", cpu, (void *)regs->nip);
pr_emerg("CPU %d self-detected hard LOCKUP @ %pS\n",
cpu, (void *)regs->nip);
pr_emerg("CPU %d TB:%lld, last heartbeat TB:%lld (%lldms ago)\n",
cpu, tb, per_cpu(wd_timer_tb, cpu),
tb_to_ns(tb - per_cpu(wd_timer_tb, cpu)) / 1000000);
print_modules();
print_irqtrace_events(current);
show_regs(regs);