From owner-freebsd-virtualization@freebsd.org Sat Oct 14 01:33:22 2017 Return-Path: Delivered-To: freebsd-virtualization@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 B2C3AE3396E for ; Sat, 14 Oct 2017 01:33:22 +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 mx1.freebsd.org (Postfix) with ESMTPS id A10338120E for ; Sat, 14 Oct 2017 01:33:22 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id v9E1XMmC004850 for ; Sat, 14 Oct 2017 01:33:22 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-virtualization@FreeBSD.org Subject: [Bug 222916] [bhyve] Debian guest kernel panics with message "CPU#0 stuck for Xs!" Date: Sat, 14 Oct 2017 01:33:22 +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: 11.1-RELEASE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: grehan@FreeBSD.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-virtualization@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc 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-virtualization@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Discussion of various virtualization techniques FreeBSD supports." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 14 Oct 2017 01:33:22 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D222916 Peter Grehan changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |grehan@FreeBSD.org --- Comment #2 from Peter Grehan --- The "CPU stuck" messages generally occurr when a system is oversubscribed i= .e. the guest has been given more virtual resources than are physically availab= le. In this case, the guest has been assigned the same number of vCPUs as the h= ost (assuming Intel-ARK is correct here: https://ark.intel.com/products/97478/Intel-Xeon-Processor-E3-1275-v6-8M-Cac= he-3_80-GHz) so if there is a time when both the host and guest require all CPUs, there = is only 4 available to service the needs of 8 assumed available (4 host, 4 gue= st). In addition, the guest has been assigned 32G of RAM, and ZFS is being used = on the host. The issue there is that the default ZFS setup on FreeBSD will all= ow use of all RAM minus 1GB for ZFS ARC. This competes with use by bhyve (swap-backed RAM), and can result in excessive swapping by the bhyve proces= s. This can also result in "CPU stuck" messages as vCPUs are halted while awai= ting guest physical memory to be paged in. A recommendation would be to a) restrict ZFS ARC usage to less than that required by the host and bhy= ve guests. In this case, perhaps 16-24G (if the mobo has 64G) ? This can be do= ne using the vfs.zfs.arc_max parameter in /boot/loader.conf b) Only use 2 vCPUs for the guest, or, enable hyperthreading. --=20 You are receiving this mail because: You are the assignee for the bug.=