linux timer using example

code:

#include <linux/init.h>#include <linux/module.h>#include <linux/hardirq.h>MODULE_LICENSE("Dual BSD/GPL");static struct timer_list timer_data;static int counter = 0;static void test_timer(unsigned long temp){int ret = 0;printk("test_timer()++\n");ret = in_interrupt();printk("in_interrupt ret = %d\n",ret);ret = in_atomic();printk("in_atomic ret = %d\n",ret);printk("counter = %d\n", counter++);mod_timer(&timer_data, jiffies + HZ);printk("test_timer()--\n");}char *ptest_str = "Hello test_timer\n";static int mmap_init(void){printk(KERN_ALERT"mmap_init()++\n");init_timer(&timer_data);timer_data.expires = jiffies + HZ;timer_data.data = (unsigned long) ptest_str;timer_data.function = test_timer;add_timer(&timer_data);printk(KERN_ALERT"mmap_init()--\n");return 0;}static void mmap_exit(void){printk(KERN_ALERT"mmap_exit()++\n");del_timer(&timer_data);printk(KERN_ALERT"mmap_exit()--\n");}module_init(mmap_init);module_exit(mmap_exit);

Makefile:

#obj-$(CONFIG_MMP_TEST)         += mmap.o  

obj-m := helloworld.o    
KERNELDR := /usr/src/linux-headers-2.6.32-38-generic/  
PWD := $(shell pwd)    
modules:    
    $(MAKE) -C $(KERNELDR) M=$(PWD) modules    
    echo "make modules"
moduels_install:    
$(MAKE) -C $(KERNELDR) M=$(PWD) modules_install    
clean:    
    rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions  

test enviroment: X86