https://bugzilla.novell.com/show_bug.cgi?id=623680 https://bugzilla.novell.com/show_bug.cgi?id=623680#c50 --- Comment #50 from Jan Beulich <jbeulich@novell.com> 2011-04-12 07:11:20 UTC --- (In reply to comment #47)
With this fix, the XEN hypervisor stops after printing (XEN) TSC: 0:0:0 (XEN) TSC: 000b48cf9339:000048cf9394:000048cf937c (XEN) TSC only partially writable
Very bad, and completely unexpected. On my dual PentiumIII system, this works just fine (just that it doesn't have any C states, and hence the actual intended effect can't be verified), so for the moment it escapes me why it would hang for you. Will need to add some more debugging code to see whether we can spot where it actually dies (I expect this is not immediately after the printed message). (In reply to comment #49)
Jan, if I'm reading your patch correctly, it would simply disable C2 and higher on my system (if it worked). But I could do the same easier with the max_cstate=1 parameter, as we discovered early on.
Yes, but the goal is to have Xen notice this by itself instead of needing a command line option, the more that we're dealing with fully specified behavior here.
OTOH, the Linux kernel runs just fine on this system with C2 and C3. What is the deeper reason behind Xen's need to write the TSC when C2/C3 are enabled?
The reason for this lies in how Xen manages time, which is completely different from Linux. Making C2/C3 usable under Xen on this systems of yours is certainly theoretically doable, but I see no point in spending time here - you'll have to acknowledge your system is not the youngest anymore ;-) . -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.