From owner-freebsd-hackers@freebsd.org Sun Dec 11 17:54:57 2016 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 90863C72984 for ; Sun, 11 Dec 2016 17:54:57 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 05AF21A6A for ; Sun, 11 Dec 2016 17:54:56 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTPS id uBBHspX8072319 (version=TLSv1 cipher=DHE-RSA-CAMELLIA256-SHA bits=256 verify=NO); Sun, 11 Dec 2016 19:54:52 +0200 (EET) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua uBBHspX8072319 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id uBBHspDu072318; Sun, 11 Dec 2016 19:54:51 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Sun, 11 Dec 2016 19:54:51 +0200 From: Konstantin Belousov To: Jilles Tjoelker Cc: Jonathan de Boyne Pollard , FreeBSD Hackers , supervision@list.skarnet.org Subject: Re: NOTE_TRACK, EVFILT_PROC, kqueue, and subreapers Message-ID: <20161211175451.GV54029@kib.kiev.ua> References: <20161201124118.46778e2b@mydesk.domain.cxm> <20161201174837.GR3428@protected.rcdrun.com> <20161201125438.15230317@mydesk.domain.cxm> <20161206104020.6b2ebb30@eto-mona.office.smartweb.sk> <20161206102637.1ddd152a@mydesk.domain.cxm> <20161207155638.4b2dd629@eto-mona.office.smartweb.sk> <630ace89-e29b-d0d3-9f15-110d8dc3de08@NTLWorld.com> <20161208132842.5d7940bd@eto-mona.office.smartweb.sk> <20161211124637.GA17315@stack.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161211124637.GA17315@stack.nl> User-Agent: Mutt/1.7.1 (2016-10-04) X-Spam-Status: No, score=-2.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.1 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on tom.home X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 11 Dec 2016 17:54:57 -0000 On Sun, Dec 11, 2016 at 01:46:38PM +0100, Jilles Tjoelker wrote: > As reported in https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=213928 > reapers do not receive SIGCHLD when inheriting zombies, although they do > receive SIGCHLD when an inherited descendant process later terminates > and are awakened when in a wait call for a matching process. This should > probably be fixed. I agree, in principle. Could you update your tests/sys/kern/reaper.c to include this scenario ? Untested change to the kernel side is below. diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c index f4f453c3556..92899740eef 100644 --- a/sys/kern/kern_exit.c +++ b/sys/kern/kern_exit.c @@ -455,6 +455,12 @@ exit1(struct thread *td, int rval, int signo) if (!(q->p_flag & P_TRACED)) { proc_reparent(q, q->p_reaper); + if (q->p_state == PRS_ZOMBIE) { + PROC_LOCK(q->p_reaper); + pksignal(q->p_reaper, SIGCHLD, q->p_ksi); + wakeup(q->p_reaper); + PROC_UNLOCK(q->p_reaper); + } } else { /* * Traced processes are killed since their existence