Date: Wed, 25 Nov 2015 03:39:49 +0000 From: bugzilla-noreply@freebsd.org To: emulation@FreeBSD.org Subject: [Bug 195819] TSC calibration can hang FreeBSD in Hyper-V Generation 2 VM Message-ID: <bug-195819-4077-WV2QfI5nbs@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-195819-4077@https.bugs.freebsd.org/bugzilla/> References: <bug-195819-4077@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=195819 Dexuan Cui <decui@microsoft.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |decui@microsoft.com, | |honzhan@microsoft.com --- Comment #16 from Dexuan Cui <decui@microsoft.com> --- (In reply to Mark Trettin from comment #11) > I believe what is happening is the TSC calibration is dropping to the i8254 PIT to > calibrate the TSC and I don't think the Generation 2 Hyper-V has that. Hi Mark, you're right. In Hyper-V generation-2 Linux VM, the ACPI timer is used to calibrate TSC. With "set machdep.disable_tsc_calibration=1", the bootup can go further but the VM still hangs later -- I guess this may be a bad side effect of disabling TSC calibration and I guess the TSC has to be calibrated here, e.g., by the ACPI timer? -- 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-195819-4077-WV2QfI5nbs>