From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 10 Dec 2001 15:31:23 -0500 From: Daniel Jacobowitz To: Kevin Hendricks Cc: linuxppc-dev@lists.linuxppc.org Subject: Re: unkillable zombies from using gdb and kernel 2.4.15 and higher? Message-ID: <20011210153123.A11283@nevyn.them.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Mon, Dec 10, 2001 at 09:11:30AM -0500, Kevin Hendricks wrote: > > Hi, > > I have been debugging a glibc-2.2.4 issue that involves forking and > reaping and threads using gdb. Unfortunately, every time I run things > under gdb I create an "unkillable" zombie process that (even after gdb > has gone away) is impossible to remove. This should never happen. There is a known bug in the kernel, for which Mark Kettenis has sent patches several times but they keep slipping through cracks, which makes exited threads live until the GDB controlling them exits. I can send you the patch if you need it. > ps -Af | grep idlc > kbhend 25532 1 0 Dec08 ? 00:00:00 [idlc] > kbhend 25529 1 0 Dec08 ? 00:00:00 [idlc] > kbhend 25541 1 0 Dec08 ? 00:00:00 [idlc] > kbhend 25543 1 0 Dec08 ? 00:00:00 [idlc] > kbhend 25540 1 0 Dec08 ? 00:00:00 [idlc] > kbhend 25552 1 0 Dec08 ? 00:00:00 [idlc] > kbhend 25554 1 0 Dec08 ? 00:00:00 [idlc] > kbhend 25551 1 0 Dec08 ? 00:00:00 [idlc] > kbhend 14796 10716 0 09:11 pts/4 00:00:00 grep idlc Have you tried rebooting and repeating? Could your init be fried? It ought to reap them. Also check /proc/pid/status on a zombie. What does it say? > [root@localhost program]# kill -9 25530 25532 25529 > [root@localhost program]# ps -Af | grep idlc > .... > kbhend 25530 1 0 Dec08 ? 00:00:00 [idlc] > kbhend 25532 1 0 Dec08 ? 00:00:00 [idlc] > kbhend 25529 1 0 Dec08 ? 00:00:00 [idlc] > > So these zombies are ignoring kill -9 signals which I thought was a big > no-no? > > Did something change in signal handling lately that allows this to > happen? You're not sending them signals. They're already dead :P -- Daniel Jacobowitz Carnegie Mellon University MontaVista Software Debian GNU/Linux Developer ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/