This patch adds a new kernel debug feature: CONFIG_DETECT_SOFTLOCKUP. When enabled then per-CPU watchdog threads are started, which try to run once per second. If they get delayed for more than 10 seconds then a callback from the timer interrupt detects this condition and prints out a warning message and a stack dump (once per lockup incident). The feature is otherwise non-intrusive, it doesnt try to unlock the box in any way, it only gets the debug info out, automatically, and on all CPUs affected by the lockup.
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| @@ -950,6 +950,7 @@ void do_timer(struct pt_regs *regs) · 949 unmodified lines | |||
| 950 | { | 950 | { |
| 951 | jiffies_64++; | 951 | jiffies_64++; |
| 952 | update_times(); | 952 | update_times(); |
| 953 | softlockup_tick(regs); | ||
| 953 | } | 954 | } |
| 954 | 955 | ||
| 955 | #ifdef __ARCH_WANT_SYS_ALARM | 956 | #ifdef __ARCH_WANT_SYS_ALARM |