From owner-freebsd-current@freebsd.org Tue Nov 5 17:44:24 2019 Return-Path: Delivered-To: freebsd-current@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 0596C1AEC37 for ; Tue, 5 Nov 2019 17:44:24 +0000 (UTC) (envelope-from brennan@umanwizard.com) Received: from smtp.umanwizard.com (smtp.umanwizard.com [54.203.248.109]) by mx1.freebsd.org (Postfix) with ESMTP id 476xqq0cMgz3KrX for ; Tue, 5 Nov 2019 17:44:22 +0000 (UTC) (envelope-from brennan@umanwizard.com) X-Fes-Encrypted: true X-Fes-Ehlo-Domain: [10.30.91.165] From: Brennan Vincent Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.11\)) Subject: Kernel panics sometimes resulting in no core dump. Message-Id: <9C7D409D-7305-4E3A-9F66-F518A8D321B8@umanwizard.com> Date: Tue, 5 Nov 2019 12:44:06 -0500 To: freebsd-current@freebsd.org X-Mailer: Apple Mail (2.3445.104.11) X-Rspamd-Queue-Id: 476xqq0cMgz3KrX X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of brennan@umanwizard.com designates 54.203.248.109 as permitted sender) smtp.mailfrom=brennan@umanwizard.com X-Spamd-Result: default: False [-2.98 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; FROM_HAS_DN(0.00)[]; R_SPF_ALLOW(-0.20)[+a]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; TO_DN_NONE(0.00)[]; DMARC_NA(0.00)[umanwizard.com]; RCPT_COUNT_ONE(0.00)[1]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; IP_SCORE(-1.18)[ipnet: 54.202.0.0/15(-4.47), asn: 16509(-1.39), country: US(-0.05)]; MV_CASE(0.50)[]; RCVD_COUNT_ZERO(0.00)[0]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:16509, ipnet:54.202.0.0/15, country:US]; MID_RHS_MATCH_FROM(0.00)[] X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 05 Nov 2019 17:44:24 -0000 (Note: I have also posted this to the forums, but upon reading the forum = guidelines more carefully I realized the mailing list is probably a = better venue. So if you are also a forum reader, I apologize for the = extra churn.) Hello, I am running 13-CURRENT (compiled recently from source using = default build settings) and recently I have been kernel panics every so = often. They can happen at any time but seem to be more likely when the = system is running a graphical environment and is at high load (e.g., = during `make -j64 buildworld`). I have configured my system to collect core dumps: my swap partition is = 50 GB (large enough to contain any conceivable minidump), `dumpon` = reports that it is indeed configured as a dump partition, and I have = `savecore_enable=3D"YES"` in /etc/rc.conf. I also have the sysctl = `debug.debugger_on_panic` set to 0, which seems to be necessary for core = dumps to happen (instead of breaking into the debugger on panic). = Before, when that sysctl was set to 1, my graphical environment would = hand; now it reboots. The changing behavior depending on the value of = `debug.debugger_on_panic` is what makes me think this really is a kernel = panic, as opposed to some other possible issue that could cause a crash. The weird thing is that when I manually cause a panic via `sudo sysctl = debug.kdb.panic=3D1` , my system reboots as expected, and a core dump = **does** get generated and saved in /var/crash! So it's only the = mysterious random crashes that aren't causing core dumps. Can anyone help me figure out why core dumps are not getting generated, = and how I can possibly debug what is going on?=