KS2012: Kernel Summit feedback

Ted Ts'o led the final session of this year's Kernel Summit (KS), which was targeted at discussing the summit itself. Over the years, there have been various changes to the format and this year was no exception. The summit was co-located with and overlapped one day of the Linux Plumbers Conference (LPC); the minisummits were moved into the middle of the summit as well. Ts'o and others wondered how well that worked and looked for input on how the meetings should be structured in the future.

Putting the minisummits on day two (Tuesday August 28) turned that day into an "all-day hallway track" for those who weren't participating, Ts'o said. That had both good and bad points, but was in general well-received. The all-day hallway track and minisummits both got a boost from the early arrival of LPC attendees.

The topic choices for day one were good, according to H. Peter Anvin and others. A little more notice of the schedule would have been useful, Anvin said, so that participants could prepare for the discussions. Mel Gorman said that the summit was "sedate" overall, though he thought the topics were well selected. It was not very "entertaining", though, because there wasn't any fighting. Christoph Hellwig noted that the people "we fight with" weren't invited.

James Bottomley wondered if it would have been better to have a "cage fight" on the first day over the two competing NUMA scheduling approaches. Linus Torvalds noted that some may have avoided the memcg minisummit (where that discussion took place), even though they were interested in NUMA scheduling, so they "didn't have to hear about memcg". But Gorman said that particular problem may have been best handled "relatively privately" in the smaller memory-management-focused group at the memcg minisummit. Opening the discussion up to larger participation might have "made a bad situation a hell of lot worse".

Torvalds had his own complaint about the minisummits: their schedules. He would rather have had shorter sessions, rather than all-day meetings, because it made it harder to switch between them. He sat in on the PCI minisummit but felt like he would have been coming into the middle of the ARM minisummit by switching to attend the AArch64 discussion. He would rather see two-hour pre-announced BoF-like sessions.

Ts'o said some of the minisummit schedules came out quite late, which left no time to negotiate changes to reduce conflicts. Hellwig said that what Torvalds was suggesting, perhaps, was the elimination of the minisummits and instead to roll those discussions into longer LPC sessions. That might mean that KS and LPC should always be combined, Bottomley said. But, Arnd Bergmann was not convinced that the influx of LPC attendees was helpful for the ARM minisummit, which was already too big, he said, and got overrun with the additional people.

Others saw few problems in the overlap with LPC, to the point where juxtaposing KS and LPC each year was discussed. One problem with that is that LPC is a North American conference, whereas KS moves around the globe. Next year, LPC will be co-located with LinuxCon in New Orleans, while KS will either be in Edinburgh with LinuxCon Europe or somewhere in Asia, possibly Hong Kong. But, it doesn't matter what the conference is called, Hellwig said, but that the format remains and the same types of attendees are present. Anvin cautioned against tying LPC to KS, noting that it can be bad for the other conference in the long run, citing the KS/Ottawa Linux Symposium combination as an example.

It might be possible to see if LPC had any interest in moving to locations outside of North America, or setting up meetings like LPC wherever KS is being held. Chris Mason noted that KS can be a draw for plumbing layer developers no matter where it is held. Dirk Hohndel thought that the same kind of KS/LPC meetings could be set up anywhere and draw in developers from afar as well as those nearby, noting that Korea or Japan would be good candidates. Ts'o agreed that these kinds of meetings bring new people into the community. He said that Hong Kong is under consideration to draw in more Chinese developers, for example.

While the co-location with LPC was seen to be mostly beneficial, the addition of LinuxCon and CloudOpen was a bit much. Those conferences started on Wednesday, which resulted in a large influx of people. That led to some confusion: the rooms where meetings had been held the previous two days were no longer available, it was unclear where to get the lunch available for KS attendees (and there was confusion over who was allowed to eat), and so on. Most in the room were not in favor of doing quite that much overlap in the future. Hohndel noted that the Linux Foundation staff were going "insane" trying to make it all work, so it is unlikely something like that will happen again.

In answer to a question from Bottomley, most present were in favor of moving the KS location each year, and there were suggestions of other possible venues down the road. Some were less likely (e.g. Cuba), while others seem quite possible (e.g. South America, Korea, or Japan again). Changing the usual (northern hemisphere) summer to fall dates for KS was discussed, but the logistics of moving to spring were considered difficult. It would have to be done in stages so that the distance between summits was kept to roughly a year. That also means, for example, that co-locating with linux.conf.au sometime (which was suggested) would be hard to do because it is held in January.

The largely minor complaints aside, the general sense from the discussion was that this year's summit had served its purpose. It got kernel hackers together to discuss areas where the kernel development process could be improved. There will undoubtedly be more tweaks to the format over the years, but the summit itself—like the kernel development process—is working pretty well.