[Lucid] Prepare virtual flavour to be usable for EC2
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Invalid
|
Wishlist
|
Unassigned | ||
Lucid |
Fix Released
|
Wishlist
|
Stefan Bader |
Bug Description
SRU Justification:
Impact:
Currently we ship a specially patched kernel in Lucid for EC2. This was due to a bug in the upstream kernel that caused the guest to crash when certain cpu features were available. This bug has been fixed upstream and in the Lucid kernel [1]. Since carrying that specially patched kernel causes more maintenance burden and may result in undetected security issues we should replace that kernel with the virtual flavour kernel (derived from server / generic-pae).
Fix:
Change Xen specific drivers to be built-in (as in the ec2 kernel now). Those drivers will not be used when not running under Xen and are therefore safe to have. They need to be built-in as they are not auto-probed. When all preparations are done, we will change the linux-meta-ec2 package to pull in the virtual binary package.
Testcase:
Replace the ec2 kernel by the virtual kernel on a ec2 system (depends on bug #1176159).
[1] commit cb72b3759fe5621
Author: Shan Haitao <email address hidden>
Date: Fri Sep 21 17:28:04 2012 +0200
xen: Allow PV-OPS kernel to detect whether XSAVE is supported
Changed in linux (Ubuntu Lucid): | |
status: | New → In Progress |
importance: | Undecided → Wishlist |
assignee: | nobody → Stefan Bader (stefan-bader-canonical) |
Changed in linux (Ubuntu): | |
status: | In Progress → Invalid |
assignee: | Stefan Bader (stefan-bader-canonical) → nobody |
Changed in linux (Ubuntu Lucid): | |
status: | In Progress → Fix Committed |
The EC2 kernel also had this revert applied:
Author: John Johansen <email address hidden>
Date: Fri Aug 20 10:16:53 2010 -0700
UBUNTU: SAUCE: Revert "sched: update load count only once per cpu in 10 tick
BugLink: http:// bugs.launchpad. net/bugs/ 574910
The final fix for that would be those two patches below. But as the ec2 problem only was caused by the fact that those kernels were not tickless, we should wait for real issues with the replacing kernels being tickless. The revert plus the two other patches were upstream in Karmic and later but we never had good reproducers.
Author: Peter Zijlstra <email address hidden>
Date: Thu Apr 22 21:50:19 2010 +0200
sched: Cure load average vs NO_HZ woes
Author: Peter Zijlstra <email address hidden>
Date: Tue Nov 30 19:48:45 2010 +0100
sched: Cure more NO_HZ load average woes