Date: Sat, 14 Oct 2017 01:33:22 +0000 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!" Message-ID: <bug-222916-27103-EzSiUm5ttz@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-222916-27103@https.bugs.freebsd.org/bugzilla/> References: <bug-222916-27103@https.bugs.freebsd.org/bugzilla/>
next in thread | previous in thread | raw e-mail | index | archive | help
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D222916 Peter Grehan <grehan@FreeBSD.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |grehan@FreeBSD.org --- Comment #2 from Peter Grehan <grehan@FreeBSD.org> --- 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.=
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?bug-222916-27103-EzSiUm5ttz>