Question

Linux实用程序＆＃34; strace＆＃34;显示运行strace后启动的系统调用列表。我怎样才能看到在当前时刻按进程运行的系统调用？在strace开始之前。

Answer 1

proc提供了一些有关内核当前正在做什么的信息＆＃34;对于＆＃34;一个过程
/proc/${pid}/syscall /proc/${pid}/stack

更多信息：

Answer 2

假设您知道进程的PID，则只需使用strace即可实时跟踪所有正在执行的系统调用。

strace -p PID

Answer 3

你发现使用ps：

ps -p PID_OF_PROC -ocmd,stat,wchan

wchan是关键所在。来自man ps：

wchan WCHAN 进程正在休眠的内核函数的名称，＆＃34; - ＆＃34;如果进程正在运行，或者a ＆＃34; *＆＃34;如果进程是多线程的，并且ps没有显示线程。

处理状态代码 以下是s，stat和state输出说明符（标题＆＃34; STAT＆＃34;或＆＃34; S＆＃34;）将显示的不同值过程的状态：

           D    uninterruptible sleep (usually IO)
           R    running or runnable (on run queue)
           S    interruptible sleep (waiting for an event to complete)
           T    stopped by job control signal
           t    stopped by debugger during the tracing
           W    paging (not valid since the 2.6.xx kernel)
           X    dead (should never be seen)
           Z    defunct ("zombie") process, terminated but not reaped by its parent

  For BSD formats and when the stat keyword is used, additional characters may be displayed:

          <    high-priority (not nice to other users)
          N    low-priority (nice to other users)
          L    has pages locked into memory (for real-time and custom IO)
          s    is a session leader
          l    is multi-threaded (using CLONE_THREAD, like NPTL pthreads do)
          +    is in the foreground process group

如何查看按进程在当前时间执行的系统调用？

3 个答案: