static int mutex_test_read(char *page, char **start, off_t off, int count, int *eof, void *data)
{
printk_dbg("========== try to get mutext...\n");
mutex_lock_interruptible(&gMutexLock);
printk_dbg("---------- has got mutext.\n");
foo(taskTime); // work task
printk_dbg("---------- try to release mutext...\n");
mutex_unlock(&gMutexLock);
printk_dbg("========== has released mutext.\n\n");
{
int len;
if (off > 0) {
*eof = 1;
return 0;
}
len = sprintf(page, "taskTime=%d.\n\n", taskTime);
return len;
}
}