Linux has at least four levels of decreasing pleasantry: -1, -2, -15, and -9, aka HangUP, INTerrupt, TERMinate and KILL or “Please stop”, “Hey! Quit it!”, “Stop it! NOW!” and *loud gunshot*.
Sometimes processes will clean up after themselves and leave when asked nicely. Or sternly told off. Of course, if you don’t need or want that, load up your, uh, -9 shooter.
You can try asking a process to round up its dead children, but unlike the quit signals, the number varies by platform. For most Linux users it’s -17, but using the text version -CHLD is probably a better choice (unless you’re on a really old system that absolutely has to have a number, in which case check the local documentation.)
If it’s a well-behaved process, that can do away with the need to kill it. In other cases, there might be some kind of restart mechanism built in that can be called instead - assuming sending it a SIGCHLD doesn’t trigger that behaviour anyway.
Case in point, the Cinnamon DE has at least a couple of ways to restart it, and at least one of those gets rid of its zombie child processes. It’s fairly rare that I need to do that, and I haven’t tried sending it a -17. I might do at some point.
Linux has at least four levels of decreasing pleasantry: -1, -2, -15, and -9, aka HangUP, INTerrupt, TERMinate and KILL or “Please stop”, “Hey! Quit it!”, “Stop it! NOW!” and *loud gunshot*.
Sometimes processes will clean up after themselves and leave when asked nicely. Or sternly told off. Of course, if you don’t need or want that, load up your, uh, -9 shooter.
To be fair, even in Linux it’s really hard to kill a zombie process. You have to tell the parent to own up to their kid, and then kill the parent.
“Stalled I/O” has entered the process list :D
You can try asking a process to round up its dead children, but unlike the quit signals, the number varies by platform. For most Linux users it’s -17, but using the text version -CHLD is probably a better choice (unless you’re on a really old system that absolutely has to have a number, in which case check the local documentation.)
If it’s a well-behaved process, that can do away with the need to kill it. In other cases, there might be some kind of restart mechanism built in that can be called instead - assuming sending it a SIGCHLD doesn’t trigger that behaviour anyway.
Case in point, the Cinnamon DE has at least a couple of ways to restart it, and at least one of those gets rid of its zombie child processes. It’s fairly rare that I need to do that, and I haven’t tried sending it a -17. I might do at some point.