Hi, I am test out a simple schedule_timeout() code. When I insert the module kernel goes in a infinite loop printing this in the log : Jul 6 22:04:35 ubuntupc kernel: [ 5738.281659] Pid: 0, comm: swapper Not tainted 2.6.35-22-generic #33-Ubuntu Jul 6 22:04:35 ubuntupc kernel: [ 5738.281663] Call Trace: Jul 6 22:04:35 ubuntupc kernel: [ 5738.281671] [<ffffffff8104d15a>] dequeue_task_idle+0x3a/0x50 Jul 6 22:04:35 ubuntupc kernel: [ 5738.281679] [<ffffffff81052d6a>] dequeue_task+0x9a/0xb0 Jul 6 22:04:35 ubuntupc kernel: [ 5738.281687] [<ffffffff81052dae>] deactivate_task+0x2e/0x40 Jul 6 22:04:35 ubuntupc kernel: [ 5738.281693] [<ffffffff81586ba9>] schedule+0x4a9/0x830 Jul 6 22:04:35 ubuntupc kernel: [ 5738.281702] [<ffffffff81008ddb>] cpu_idle+0xeb/0x110 Jul 6 22:04:35 ubuntupc kernel: [ 5738.281710] [<ffffffff815832ad>] start_secondary+0x100/0x102 Any ideas on what is going on ? ---------------------------------- <testmod.c> ---------------------------------- #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/timer.h> #include <linux/delay.h> #include <linux/sched.h> struct timer_list tim; void timfunc(unsigned long data) { printk("hi this is a timer %lu\n", data); set_current_state(TASK_INTERRUPTIBLE); schedule_timeout(10 * HZ); printk("hi again this is a timer after timeout %lu\n", data); } static int __init init_testmod(void) { init_timer(&tim); tim.expires = jiffies + HZ*5; tim.data = 1000; tim.function = timfunc; add_timer(&tim); return 0; } static void __exit exit_testmod(void) { printk("end of module\n"); return; } module_init(init_testmod); module_exit(exit_testmod); MODULE_LICENSE("GPL"); ------------------------------ </testmod.c> ---------------------------------- ---------------------------------- <Makefile> ---------------------------------- obj-m += testmod.o KERNELDIR ?= /lib/modules/$(shell uname -r)/build PWD := $(shell pwd) default: $(MAKE) -C $(KERNELDIR) M=$(PWD) clean: rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions depend .depend dep: $(CC) $(CFLAGS) -M *.c > .depend ifeq (.depend,$(wildcard .depend)) include .depend endif ---------------------------------- </Makefile> ----------------------------------