Andrew Morton is well-known in the kernel community for doing a wide variety of different tasks: maintaining the -mm tree for patches that may be on their way to the mainline, reviewing lots of patches, giving presentations about working with the community, and, in general, handling lots of important and visible kernel development chores. Things are changing in the way he does things, though, so we asked him a few questions by email. He responded at length about the -mm tree and how that is changing with the advent of linux-next, kernel quality, and what folks can do to help make the kernel better.

Years ago, there was a great deal of worry about the possibility of burning out Linus. Life seems to have gotten easier for him since then; now instead, I've heard concerns about burning out Andrew. It seems that you do a lot; how do you keep the pace and how long can we expect you to stay at it?

I do less than I used to. Mainly because I have to - you can't do the same thing at a high level of intensity for over five years and stay sane.

I'm still keeping up with the reviewing and merging but the -mm release periods are now far too long.

There are of course many things which I should do but which I do not.

Over the years my role has fortunately decreased - more maintainers are running their own trees and the introduction of the linux-next tree (operated by Stephen Rothwell) has helped a lot.

The linux-next tree means that 85 per cent of the code which I used to redistribute for external testing is now being redistributed by Stephen. Some time in the next month or two I will dive into my scripts and will find a way to get the sufficiently-stable parts of the -mm tree into linux-next and then I will hopefully be able to stop doing -mm releases altogether.

So. The work level is ramping down, and others are taking things on.

What can we do to help?

I think code review would be the main thing. It's a pretty specialised function to review new code well. The people who specialise in the area which the new code is changing are the best reviewers but unfortunately I will regularly find myself having to review someone else's stuff.

Secondly: it would help if people's patches were less buggy. I still have to fix a stupidly large number of compile warnings and compilation errors and each -mm release requires me to perform probably three or four separate bisection searches to weed out bad patches.

Thirdly: testing, testing, testing.

Fourthly: it's stupid how often I end up being the primary responder on bug reports. I'll typically read the linux-kernel list in 1000-email batches once every few days and each time I will come across multiple bug reports which are one to three days old and which nobody has done anything about! And sometimes I know that the person who is responsible for that part of the kernel has read the report. grr.