qemu appears to be built without CONFIG_NUMA defined

It looks like it is mainly disabled because it is in Debian, see
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=758189

The reasons for disabling it in Debian don't strictly apply in
ubuntu, so it may be ok for us to enable it.

 status: triaged
 importance: high

Looks like libnuma is not supported on arm. That complicates the enablement.

Is it possible to conditionally enable it based on architecture? Or does Ubuntu try to keep the packages configured the same across all architectures?

Yup, we should be able to do Build-depends: libnuam-dev [ x86 arm64 ... ]

I will test something along those lines tomorrow.

This bug was fixed in the package qemu - 1:2.2+dfsg-5expubuntu5

---------------
qemu (1:2.2+dfsg-5expubuntu5) vivid; urgency=medium

  * debian/control-in: enable numa on architectures where numa is built
    (LP: #1417937)
 -- Serge Hallyn <email address hidden> Thu, 12 Feb 2015 23:18:58 -0600

would this be back-port to utopic ?

Quoting li,chen (<email address hidden>):
> would this be back-port to utopic ?

It's a new features, so doesn't strictly fall under SRU guidelines.
(See https://wiki.ubuntu.com/StableReleaseUpdates)

One could argue that the NUMA functionality wasn't intentionally turned off (it was inherited from debian) and thus re-enabling it would be fixing a bug.

Just as some background...the kilo release of OpenStack (currently under way) introduced support for NUMA guests (per-NUMA node hugepage support, guests with multiple NUMA nodes, pinning guest NUMA node to host NUMA node, etc.). If Ubuntu (which is currently one of the more popular OpenStack host distros) doesn't support NUMA in qemu by default, it's going to complicate things.

Quoting Chris Friesen (<email address hidden>):
> One could argue that the NUMA functionality wasn't intentionally turned
> off (it was inherited from debian) and thus re-enabling it would be
> fixing a bug.

That would definitely be the case if it had been on in precise or trusty,
but that doesn't seem to be the case.

> Just as some background...the kilo release of OpenStack (currently under
> way) introduced support for NUMA guests (per-NUMA node hugepage support,
> guests with multiple NUMA nodes, pinning guest NUMA node to host NUMA
> node, etc.). If Ubuntu (which is currently one of the more popular
> OpenStack host distros) doesn't support NUMA in qemu by default, it's
> going to complicate things.

If you only want this in utopic, I think I feel comfortable trying for
that. For trusty I'd be more hesitant, but we can still try - with
a lot of testing.

I don't want to give you more work than necessary.

If we can get it for utopic that'd be great...at least then we'd have one formally released version of Ubuntu that supported it.

Hello Chris, or anyone else affected,

Accepted qemu into utopic-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/qemu/2.1+dfsg-4ubuntu6.5 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

Verified on utopic.

This bug was fixed in the package qemu - 2.1+dfsg-4ubuntu6.5

---------------
qemu (2.1+dfsg-4ubuntu6.5) utopic-proposed; urgency=medium

  * debian/control-in: enable numa on architectures where numa is built
    (LP: #1417937)
 -- Serge Hallyn <email address hidden> Tue, 17 Feb 2015 14:13:00 -0600

The verification of the Stable Release Update for qemu has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.