在makefile中创建的一个shell脚本，应该测试程序，我有一个“killall -QUIT -w chatty”行。 我已经阅读了文档，它说killall -w仅在目标进程终止时返回。
killall -QUIT -w chatty
HANDLER : Recieved SIGQUIT
DISPATCHER : Shutting down...
WORKER 0 : Shutting down...
WORKER 1 : Shutting down...
WORKER 3 : Shutting down...
WORKER 6 : Shutting down...
WORKER 2 : Shutting down...
WORKER 5 : Shutting down...
WORKER 7 : Shutting down...
WORKER 4 : Shutting down...
HANDLER : Terminating
-------------------- CHATTY TERMINATIG --------------------
# this is where the process terminates, and where the killall should
# terminate too, but it remains active.
ps
PID TTY TIME CMD
9094 pts/2 00:00:00 bash
21398 pts/2 00:00:00 make
21469 pts/2 00:00:00 killall
21471 pts/2 00:00:00 ps
可能导致此问题的原因是什么？ 我已经检查了僵尸进程，但它不存在。