If sysctl_hardlockup_all_cpu_backtrace is enabled, there is no need to
IPI stuck CPUs for backtrace before trigger_allbutself_cpu_backtrace(),
which does the same thing again.
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
arch/powerpc/kernel/watchdog.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/kernel/watchdog.c b/arch/powerpc/kernel/watchdog.c
index 532a1adbe89b..920e61c79f47 100644
--- a/arch/powerpc/kernel/watchdog.c
+++ b/arch/powerpc/kernel/watchdog.c
@@ -133,15 +133,18 @@ static void watchdog_smp_panic(int cpu, u64 tb)
pr_emerg("Watchdog CPU:%d detected Hard LOCKUP other CPUS:%*pbl\n",
cpu, cpumask_pr_args(&wd_smp_cpus_pending));
- /*
- * Try to trigger the stuck CPUs.
- */
- for_each_cpu(c, &wd_smp_cpus_pending) {
- if (c == cpu)
- continue;
- smp_send_nmi_ipi(c, wd_lockup_ipi, 1000000);
+ if (!sysctl_hardlockup_all_cpu_backtrace) {
+ /*
+ * Try to trigger the stuck CPUs, unless we are going to
+ * get a backtrace on all of them anyway.
+ */
+ for_each_cpu(c, &wd_smp_cpus_pending) {
+ if (c == cpu)
+ continue;
+ smp_send_nmi_ipi(c, wd_lockup_ipi, 1000000);
+ }
+ smp_flush_nmi_ipi(1000000);
}
- smp_flush_nmi_ipi(1000000);
/* Take the stuck CPUs out of the watch group */
set_cpumask_stuck(&wd_smp_cpus_pending, tb);
--
2.13.3
