From owner-freebsd-bugs@FreeBSD.ORG Sat Jan 28 18:30:14 2012 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D1AFC106564A for ; Sat, 28 Jan 2012 18:30:14 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id BBBDC8FC08 for ; Sat, 28 Jan 2012 18:30:14 +0000 (UTC) Received: from freefall.freebsd.org (localhost [127.0.0.1]) by freefall.freebsd.org (8.14.5/8.14.5) with ESMTP id q0SIUEWY076193 for ; Sat, 28 Jan 2012 18:30:14 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.5/8.14.5/Submit) id q0SIUEtC076188; Sat, 28 Jan 2012 18:30:14 GMT (envelope-from gnats) Date: Sat, 28 Jan 2012 18:30:14 GMT Message-Id: <201201281830.q0SIUEtC076188@freefall.freebsd.org> To: freebsd-bugs@FreeBSD.org From: Jilles Tjoelker Cc: Subject: Re: bin/164526: kill(1) can not kill process despite on -KILL X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Jilles Tjoelker List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 28 Jan 2012 18:30:14 -0000 The following reply was made to PR bin/164526; it has been noted by GNATS. From: Jilles Tjoelker To: bug-followup@FreeBSD.org, kes-kes@yandex.ru Cc: Subject: Re: bin/164526: kill(1) can not kill process despite on -KILL Date: Sat, 28 Jan 2012 19:24:07 +0100 > [stuck process cannot be killed, system hangs when reboot is > attempted] A signal cannot forcibly kill a process that is stuck in the kernel. Allowing this would put the integrity of the kernel data structures at risk and likely cause hangs, data corruption or panics later on. If a process is stuck in the kernel for a long time, this can be things like broken hardware, a non-responsive NFS server or a bug. A state 'T' (stopped) probably means the process is multi-threaded and is trying to suspend but one or more threads will not cooperate (non-interruptible sleep or running in the kernel). Useful commands to obtain more information (supposing pid is 45471): ps Hl45471 procstat -k 45471 Of course, this does not help if you already rebooted. -- Jilles Tjoelker