进程使用proc导出信息

STEP 1: Add a field named can_pick in task_struct. Now we want to export it to user space by proc file system.
 

struct task_struct{
...
int can_pick;
...
}

STEP 2: change to kernel source tree, in fs/proc/base.c, add following code at proper line.

2633     INF("can_pick",   S_IRUGO, proc_pid_can_pick),


and,

367 static int proc_pid_src_cpu(struct task_struct *task, char *buffer)
 368 {
 369 return sprintf(buffer,"%d\n",task->src_cpu);
 370 }


STEP 3: compile kernel. cat /proc/xxx/can_pick.