Red Hat Bugzilla – Bug 770153
vdsm-bootstrap should not set max_cstate=1 to the kernel command line
Last modified: 2016-04-26 22:08:23 EDT
+++ This bug was initially created as a clone of Bug #770123 +++
+++ This bug was initially created as a clone of Bug #770122 +++
Description of problem:
max_cstate=1 was added to kernel defaults for oVirt Node due to a large portion of hardware having issues w/ time sync in kvm.
As long as hardware has a stable/constant tsc, it should be safe to remove this restriction. People with older hardware can always manually add it back in.
Need to remove it from vdsm-bootstrap:
[root@rhevm-3 vdsm-bootstrap]# grep -R cstate *
vds_bootstrap.py: args += ['processor.max_cstate=1']
This was requested by rhev-3.0 bug 579705, so I'd be keeping max_cstate for rhel6.
(In reply to comment #1)
> This was requested by rhev-3.0 bug 579705, so I'd be keeping max_cstate for
I believe it's no longer needed.
Note that ovirt-node have removed it already - https://bugzilla.redhat.com/show_bug.cgi?id=770123
And the logic to set/remove it - https://bugzilla.redhat.com/show_bug.cgi?id=770123#c2
I am not at all sure that ovirt-node has satisfied Andy's requirement of https://bugzilla.redhat.com/show_bug.cgi?id=770123#c1
.. we check /proc/cpuinfo flags for constant_tsc and if it's NOT present we add the max_cstate otherwise we leave it off.
This is a logic that vdsmd does not have. Sp this patch is partial.
I agree this should not be used. Will be removed unless someone has any new input.
new bootstrap will warn if no constant_tsc.
3.2 beta built, moving to ON_QA status to allow testing