进程状态小记

PROCESS STATE CODES        Here are the different values that the s, stat and state output specifiers (header "STAT" or "S") will display to describe the state        of a process.        D    Uninterruptible sleep (usually IO)        R    Running or runnable (on run queue)        S    Interruptible sleep (waiting for an event to complete)        T    Stopped, either by a job control signal or because it is being traced.        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