From owner-freebsd-fs@freebsd.org Fri Aug 3 08:57:08 2018 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 273431062AB3 for ; Fri, 3 Aug 2018 08:57:08 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.ysv.freebsd.org (mailman.ysv.freebsd.org [IPv6:2001:1900:2254:206a::50:5]) by mx1.freebsd.org (Postfix) with ESMTP id A278E77BF1 for ; Fri, 3 Aug 2018 08:57:07 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.ysv.freebsd.org (Postfix) id 6497A1062AB1; Fri, 3 Aug 2018 08:57:07 +0000 (UTC) Delivered-To: fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 42A4D1062AB0 for ; Fri, 3 Aug 2018 08:57:07 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.ysv.freebsd.org (mxrelay.ysv.freebsd.org [IPv6:2001:1900:2254:206a::19:3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mxrelay.ysv.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id C459277BEF for ; Fri, 3 Aug 2018 08:57:06 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.ysv.freebsd.org (Postfix) with ESMTPS id 18989A8B7 for ; Fri, 3 Aug 2018 08:57:06 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id w738v5NQ047714 for ; Fri, 3 Aug 2018 08:57:05 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id w738v5o2047713 for fs@FreeBSD.org; Fri, 3 Aug 2018 08:57:05 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: fs@FreeBSD.org Subject: [Bug 229986] Terminating virtualbox or ctld + zfs scrub + gstat leads to deadlock Date: Fri, 03 Aug 2018 08:57:05 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 11.2-RELEASE X-Bugzilla-Keywords: regression X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: d8zNeCFG@aon.at X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: fs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 Aug 2018 08:57:08 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D229986 --- Comment #9 from Martin Birgmeier --- Actually I am quite sure that the system *is* in a kind of memory deadlock = at least in the case where it ultimately gets stuck completely (comment #4). In that case, if I remember correctly, it also used quite some swap (around 5%= of 20G configured). But for the issue with scrubbing interacting badly with shutting down VMs a= nd stopping ctld, this happens without too much memory pressure. Specifically, I have: - 16G main memory; this initially gives vfs.zfs.arc_max: 15371956224, which= is high, considering that dmesg.boot shows real memory =3D 17179869184 (16384 MB) avail memory =3D 16344322048 (15587 MB) - Then use sysctl vfs.zfs.arc_max=3D9000000000 - The VM run directly on this machine has 3G simulated physical memory The scrub has completed in the meantime, and I don't really want to restart= it, having taken 360 hours in total, and with it being very taxing on the disks= . So it is difficult to replay the scenario now. However, what is still happening and may be related to memory pressure agai= n: When I shut down ctld after many hours of operation of this machine using 'service ctld onestop' (see comment #2), in contrast to 11.1 this operation= may take several minutes. I believe this happens especially if I forget to redu= ce arc_max. In this case again it looks to me like memory pressure and that the system takes a long time to get some free memory which seems to be required for th= is operation. Maybe it is related to zvols, both the VM running directly on the machine as well as the ctld reference zvols. -- Martin --=20 You are receiving this mail because: You are the assignee for the bug.=