systemtap显示调用树

脚本：

function trace(entry_p) {
   if(tid() in trace)
       printf("%s%s%s\n",thread_indent(entry_p),
                         (entry_p>0?"->":"<-"),
                         probefunc())
}

global trace
probe kernel.function(@1).call {
   if (execname() == "stapio") next # skip our own helper process
   trace[tid()] = 1
   trace(1)
}
probe kernel.function(@1).return {
   trace(-1)
   delete trace[tid()]
}

probe kernel.function(@2).call { trace(1) }
probe kernel.function(@2).return { trace(-1) }

结果：

# stap para-callgraph.stp sys_read '*@fs/*.c'
[...]
     0 klogd(1391):->sys_read
    14 klogd(1391): ->fget_light
    22 klogd(1391): <-fget_light
    27 klogd(1391): ->vfs_read
    35 klogd(1391):  ->rw_verify_area
    43 klogd(1391):  <-rw_verify_area
    49 klogd(1391):  ->kmsg_read
     0 sendmail(1696):->sys_read
    17 sendmail(1696): ->fget_light
    26 sendmail(1696): <-fget_light
    34 sendmail(1696): ->vfs_read
    44 sendmail(1696):  ->rw_verify_area
    52 sendmail(1696):  <-rw_verify_area
    58 sendmail(1696):  ->proc_file_read
    70 sendmail(1696):   ->loadavg_read_proc
    84 sendmail(1696):    ->proc_calc_metrics
    92 sendmail(1696):    <-proc_calc_metrics
    95 sendmail(1696):   <-loadavg_read_proc
   101 sendmail(1696):  <-proc_file_read
   106 sendmail(1696):  ->dnotify_parent
   115 sendmail(1696):  <-dnotify_parent
   119 sendmail(1696):  ->inotify_dentry_parent_queue_event
   127 sendmail(1696):  <-inotify_dentry_parent_queue_event
   133 sendmail(1696):  ->inotify_inode_queue_event
   141 sendmail(1696):  <-inotify_inode_queue_event
   146 sendmail(1696): <-vfs_read
   151 sendmail(1696):<-sys_read
[...]
^C

引用地址：http://sourceware.org/systemtap/wiki/WSCallGraph?highlight=