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 --- include/linux/sched.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index 4cae9b81a1f..54cbabf3b87 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -293,6 +293,9 @@ extern void sched_show_task(struct task_struct *p); extern void softlockup_tick(void); extern void touch_softlockup_watchdog(void); extern void touch_all_softlockup_watchdogs(void); +extern int proc_dosoftlockup_thresh(struct ctl_table *table, int write, + struct file *filp, void __user *buffer, + size_t *lenp, loff_t *ppos); extern unsigned int softlockup_panic; extern unsigned long sysctl_hung_task_check_count; extern unsigned long sysctl_hung_task_timeout_secs; -- cgit v1.2.3-70-g09d2 From 336f6c322d87806ef93afad6308ac65083a865e5 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 22 Jan 2009 09:50:44 +0100 Subject: debugobjects: add and use INIT_WORK_ON_STACK Impact: Fix debugobjects warning debugobject enabled kernels spit out a warning in hpet code due to a workqueue which is initialized on stack. Add INIT_WORK_ON_STACK() which calls init_timer_on_stack() and use it in hpet. Signed-off-by: Thomas Gleixner --- arch/x86/kernel/hpet.c | 3 ++- include/linux/workqueue.h | 6 ++++++ 2 files changed, 8 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c index cd759ad9069..64d5ad0b8ad 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -628,11 +628,12 @@ static int hpet_cpuhp_notify(struct notifier_block *n, switch (action & 0xf) { case CPU_ONLINE: - INIT_DELAYED_WORK(&work.work, hpet_work); + INIT_DELAYED_WORK_ON_STACK(&work.work, hpet_work); init_completion(&work.complete); /* FIXME: add schedule_work_on() */ schedule_delayed_work_on(cpu, &work.work, 0); wait_for_completion(&work.complete); + destroy_timer_on_stack(&work.work.timer); break; case CPU_DEAD: if (hdev) { diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index b36291130f2..20b59eb1fac 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -124,6 +124,12 @@ struct execute_work { init_timer_deferrable(&(_work)->timer); \ } while (0) +#define INIT_DELAYED_WORK_ON_STACK(_work, _func) \ + do { \ + INIT_WORK(&(_work)->work, (_func)); \ + init_timer_on_stack(&(_work)->timer); \ + } while (0) + /** * work_pending - Find out whether a work item is currently pending * @work: The work item in question -- cgit v1.2.3-70-g09d2