From baf48f6577e581a9adb8fe849dc80e24b21d171d Mon Sep 17 00:00:00 2001 From: Mandeep Singh Baines Date: Mon, 12 Jan 2009 21:15:17 -0800 Subject: softlock: fix false panic which can occur if softlockup_thresh is reduced At run-time, if softlockup_thresh is changed to a much lower value, touch_timestamp is likely to be much older than the new softlock_thresh. This will cause a false softlockup to be detected. If softlockup_panic is enabled, the system will panic. The fix is to touch all watchdogs before changing softlockup_thresh. Signed-off-by: Mandeep Singh Baines Signed-off-by: Ingo Molnar --- kernel/softlockup.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'kernel/softlockup.c') diff --git a/kernel/softlockup.c b/kernel/softlockup.c index d9188c66278a..85d5a2455103 100644 --- a/kernel/softlockup.c +++ b/kernel/softlockup.c @@ -16,6 +16,7 @@ #include #include #include +#include #include @@ -88,6 +89,14 @@ void touch_all_softlockup_watchdogs(void) } EXPORT_SYMBOL(touch_all_softlockup_watchdogs); +int proc_dosoftlockup_thresh(struct ctl_table *table, int write, + struct file *filp, void __user *buffer, + size_t *lenp, loff_t *ppos) +{ + touch_all_softlockup_watchdogs(); + return proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos); +} + /* * This callback runs from the timer interrupt, and checks * whether the watchdog thread has hung or not: -- cgit v1.2.3