Time for a Linux Bug-Fixing Cycle

AlanS2002 writes "As reported here on Slashdot last week, there are some people who are concerned that the Linux Kernel is slowly getting buggier with the new development cycle. Now, according to Linux.com (Also owned by VA) Linus Torvalds has thrown his two cents in, saying that while there are some concerns, it is not as bad as some might have thought from the various reporting. However he says that the 2.6 Kernel could probably do with a breather to get people to calm down a bit."

Comments

I preferred the old odd/even split

[WillerZ]

As a user, I preferred the old odd/even unstable/stable code split; I'd run .even at work and .odd at home.

I suppose if you buy your linux off the shelf you can complain to your vendor, but for home users looking to do some DIY kernel building the new way is a bit worse. However, I suspect we're a dying breed...

Re:I preferred the old odd/even split

[gowen]

I was wondering could someone explain to my why this (IMHO) good development model was abandoned in favour of continuous feature-adding in the 2.6 kernel?

It was very, very slow, (ironically, even Andrew Morton complained about this). This meant that desirable new features would be backported to the stable branch anyway, either in mainstream or vendor kernels (with all new bugs), which kind of defeated the object.

So it increased the workload, didn't seem to offer massive stability benefits (although, maybe it did, in retrospect), it reduced the amount of testing the new features got, and limited the workloads on which they were tested.

Personally, I find the present -stable branch of non-bleeding edge kernels to be as solid as 2.4 and 2.2 ever were. I do think we've a tendency to look back at that dev-cycle with rose-tinted glasses. It's not as if 2.4 or 2.2 were reasonably bug-free until the twentieth cycle or so.

Re:I preferred the old odd/even split

[Mr Z]

No, the 2.6.x.y are patch releases of 2.6.x. The development releases are 2.6.x-preY. The release candidates are 2.6.x-rcY.

Makes sense to me at least.

--Joe

Re:I preferred the old odd/even split

[diegocgteleline.es]

The "stable/unstable" development model does not work so well with huge projects like the linux kernel is.

With the old model, the linux kernel would start a unstable release and people would start adding stuff which not the care you'd put into merging something in a stable tree, is not tested a lot, etc...

Now keep this for one, two years. When you decide to release the unstable tree as the next stable version you realize that your unstable tree is full of crap, and you need to waste months or years (Vista) trying to stabilize it. Even when you release the .0 version it's still unstable, so people has to wait even more months to start using it.

The "new" development fixed that. In the current linux development model people is allowed to put new features in the kernel even if they're invasive. But programmers are not allowed to put crap in the kernel, they need to be VERY WELL tested (in the -mm tree) and reviewed, show numbers that back your words if neccesary, document things, etc. Of course no code is free of bugs, so the released version will not be 100% stable as current 2.4 is, but it's QUITE stable.

Because the features are merged progressively, it's MUCH easier to find and fix bugs. Even if there're new features in every release, there're not a LOT of new features - it's much easier to find out what feature broke something between two releases. Compare it with a stable/unstable development model: People keeps adding things for years, when the user switches from 2.4.x to 2.6.0 his kernel doesn't boot. How do you find out who broke that with so many changes?

IMO, from a Q/A POV, the new development model has more sense than a pure stable/unstable development model. It's about "progressive" vs "disruptive", and for projects with several millions of lines and so many contributors it may have sense. Of course, because new things got added there're always some bugs, which is what people is bitching about today. Maybe this could be fixed by leaving the current tree as "stable" and start a new tree - but instead of a "unstable" 2.7 tree, a 2.8 "stable" tree. A pure unstable release doesn't works that well with huge projects like the linux kernel. Remember the hell that FreeBSD 5.x was and how much has affected to the FreeBSD project, remember windows Vista. Maybe it works for some people, but I don't thing it's the best development model for such projects. Solaris is also using this model to some extent - they release things into opensolaris, but what you see in opensolaris is not the "official stable release", it only becomes "stable" after a while.

Standardize the Kernel API!!

[mlwmohawk]

I have been using Linux since the early 1990's and I've been a software developer for almost 30 years. The one ting that concerns me, and I think this recent indictment is just a symptom of a larger problem.

The problem is that the drivers have to remain in constant flux because the kernel API is always changing. Now, when there are a limited number of drivers, this means that you can move quickly on the kernel. As you add more and more drivers, you add more and more work to keep the drivers updated. Eventually, there is more work needed to update the drivers than modify the kernel, and the drivers become your sticking point.

This is where I believe Linux is stuck. Linus and the kernel team has to look at the various kernel APIs and standardize them with the next release.

Sorry guys, time to grow up. Linux *is* mainstream!

Re:Standardize the Kernel API!!

[John_Sauter]

As a software developer whose experience goes back more than 40 years, to the Stanford Time-Sharing System on the DEC PDP-1, I can assure you that the only way to keep the kernel API from changing is to kill the project. Just as you wouldn't expect a driver written for Microsoft's MS-DOS to be effective on a modern NUMA machine, you shouldn't expect any driver interface standardized today to be effective 10 or 20 years from now. An attempt to freeze the driver API would hamstring the kernel developers, making the kernel less interesting to work on. Somebody would fork it, to lift the compatibility restriction, and the new kernel would work much better with modern computers, causing everyone to migrate to it.

The only way to keep Linux relavent it to let it evolve. Yes, that creates a burden on driver writers. Linux has a partial solution: keep your drivers in the kernel source tree, and test each kernel to be sure your driver still works. When it breaks the cause should be obvious, and easily fixed. If you are lucky, the person who changed the API will also update your driver, but you can't count on that, which is why you must test.