Increasing testing of unreleased kernels.

This past weekend I’ve been thinking of reviving an idea that has come up countless times. Producing RPM builds of the rawhide kernel for our already released Fedoras. The reason for not doing them so far has come down to bandwidth. (in terms of build system throughput, disk space, mirroring, and people bandwidth).

What I’m toying with doing is some devel kernels for Fedora 11 that are built outside of the Fedora build system. The Fedora kernel team now has enough build bandwidth for x86-[64] that we can actually get builds for those architectures done faster than koji.

Disk space – I’m thinking of just keeping the last 2-3 builds available.

Mirroring – Instead of having these be part of Fedora proper, I think an external repo on something like will suffice.

Which just leaves people bandwidth. For the most part the work is going to be just regularly syncing the devel/ branch with a CVS branch of F-11/ For some of this work, some scripting could be done to alleviate some of the pain. Also the frequency at which we push out these builds will determine the pain point. Perhaps every -git isn’t particularly valuable anyway. One build every handful of -git’s should be sufficient for bisecting.

There does remain one additional barrier. Occasionally we introduce something in rawhide builds which just won’t work on F11. For example, the kernel modesetting patches are tied closely to Xorg packages. Sometimes upstream changes require changes in mkinitrd or udev or some other ‘plumbing’. Some of these are regressions, and hopefully by identifying them sooner we can get them reverted/fixed upstream. Sometimes however, things get deprecated, and we need to change these packages. I’m not sure how to cope with this yet in a devel-for-F11 scenario.

One other thing that might be fun to throw into this would be the generation of -vanilla packages. The only reasons we don’t do these as part of the regular kernel builds is the various bandwidth concerns above. The specfile copes with spitting out RPMs with very little work needed. Josh Boyer has been occasionally doing these builds, though there hasn’t been a huge uptake. It’s unclear if this is due to lack of interest, or just a lack of publicity.

Another question to be answered is whether we go the route of enabling debugging in all builds as we do in rawhide, or do separate -debug builds. I’m leaning towards the latter.

I’m not committing anything to this for sure just yet, but it’s something I’ve been giving quite a bit of thought. There are still a bunch of unanswered questions.

2 thoughts on “Increasing testing of unreleased kernels.”

  1. RPM builds of the rawhide kernel for already released Fedoras is excellent
    idea. Sometimes I need new kernel to test new features, but I’m too lazy to
    reinstall my relatively stable workstation to rawhide or manually rebuild
    Linus’ kernel tree ;-)

  2. I think that presto should be considered to save space and/or bandwidth on those tests, maybe using as a base the latest normal kernel, for instance.

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