commit bd44874d1f058ace12633cf7987d8cae86480618
author Kyle Yan <kyan@codeaurora.org> Mon Aug 21 15:10:31 2017 -0700
committer Kyle Yan <kyan@codeaurora.org> Mon Aug 28 11:25:03 2017 -0700
tree 1497d45153157a00adade4f1f2950f1a59c1f2d9
parent f3fbc3a370988b092f18589c7585955a83160e9a

ANDROID: hardlockup: detect hard lockups without NMIs using secondary cpus

This patch adds back the hardlockup detection without NMIs from
<aaf78ec6c898b72>("ANDROID: hardlockup: detect hard lockups without NMIs
using secondary cpus") which was reverted after the hard lockup detection
logic was moved to a separate file in <b969a240448bfd8>("kernel/watchdog.c:
move hardlockup detector to separate file").

Change-Id: If6a24b379d29fa582344fe57d26df4bd2b8cc89f
Signed-off-by: Kyle Yan <kyan@codeaurora.org>

kernel/watchdog.c

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index cffb5f2..cfbf027 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -81,10 +81,10 @@
 static DEFINE_PER_CPU(unsigned int, watchdog_en);
 static DEFINE_PER_CPU(bool, softlockup_touch_sync);
 static DEFINE_PER_CPU(bool, soft_watchdog_warn);
-static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts);
 static DEFINE_PER_CPU(unsigned long, soft_lockup_hrtimer_cnt);
 static DEFINE_PER_CPU(struct task_struct *, softlockup_task_ptr_saved);
-static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved);
+DEFINE_PER_CPU(unsigned long, hrtimer_interrupts);
+DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved);
 static unsigned long soft_lockup_nmi_warn;
 
 unsigned int __read_mostly softlockup_panic =
@@ -254,6 +254,10 @@
 {
 }
 
+void __weak watchdog_check_hardlockup_other_cpu(void)
+{
+}
+
 static int watchdog_enable_all_cpus(void);
 static void watchdog_disable_all_cpus(void);
 
@@ -271,6 +275,9 @@
 	/* kick the hardlockup detector */
 	watchdog_interrupt_count();
 
+	/* test for hardlockups on the next cpu */
+	watchdog_check_hardlockup_other_cpu();
+
 	/* kick the softlockup detector */
 	wake_up_process(__this_cpu_read(softlockup_watchdog));