2.6 and 2.7 Release Management

An anonymous reader writes: "A recent discussion on the Linux kernel mailing list debated whether the upcoming 2.6 and 2.7 kernels should be released at the same time instead of first stabilizing the 2.6 'stable tree' then branching the 2.7 'development tree.' The theory behind the proposition is to keep "new" things from going into 2.6 once it is released, focusing instead only on making it stable. On the flip side of this argument is the possibility that with a 2.7 kernel in development, there will be too little focus on stabilizing the 2.6 kernel. The resulting debate makes for an interesting read."

Comments

Re:Don't forget the past

[Anonymous Coward]

This is true. The VM that came with 2.4 was so broken that we were seeing systems go down with massive data loss almost within hours of extensive use.

The old VM has 4 different major bugs:

1. Concurrent processes could not place deadlocks on sibling process in SMP mode.

2. Utilization of VM code on tread process in UP and SMP systems were so bad (under load - ( specially when the 4gig mem system was used )), that more preformance would have been got by running the 2.0 series rather than 2.4's VM.

3. No checks were placed in thread corruption and bucket fill code, which caused other nice things under load.

4. The enter beast was so unyeilding, it was known that the only one person who ever understood it, had to keep a journal just to keep track of the beast (Seriously). This was one of the major reasons that ticked off Linus and I believe the reason why he pushed the new VM.

But the 2.4 series was a major testbest. The moment we released it without having a 2.5 out, ppl started testing 2.4 in much more demand than they did the previous development series. This gave feedback in a week that we could not have got in six months for the development kernel.

The new VM has been stabilized and it's working wonderfully, if you use any kernel above 2.4.16, you should be fine.

jr

Re:What are the proposed new features in 2.5 and 2

[crsm]

The linux kernel,. besides stability .. what sort of things do they want top add/improve?

There is a list of the new features in 2.5 here.

In summary:

Performance

• Major rewrite of the disk IO layer meaning better harddisk performance for Joe-user and high-end database servers as well
• New and faster scheduler
• Pre-empt scheduling for better interactive performance

Features

• ALSA sound infrastructure
• Video for Linux redesign
• ACPI interface and other power-control patches. Especially a new software suspend-to-disk feature that does not involve Windows specific BIOS magic.
• Lots of high-end features (High memory, 64 bit processor support, per-CPU infrastructure, hot-swap CPU etc.etc.)
• JFS - Journaling filesystem from IBM (where's XFS?)
• Bluetooth
• USB-2.0

Security

• Access Control Lists (ACL) which gives fine-grained security
• Per-process namespaces (some Al Viro hackery. Someone please tell that man to slow down a bit)
• Plugable quota system

And as usual a lot of new driver updates.

Suspiciously missing are any memory management patches (although Rik has his reversed mapping patch in the pipe). Perhaps the topic is still a litte too hot... ;-)

The most important thing for me would be resource management features .. such as being able to allocate how much CPU, memory, or disk space a particular user or process can use. These are things that solaris has had for a long time .. and it seems that linux kernel developers arent interested in adding those features .. how can linux hope to take over the enterprise server market without it?

I think that the with the current kernel you can already do much of this. But some of the new features of the 2.5 kernel allows for much more fine-grained control - like binding a process to a distinct CPU, better quota accounting etc. Perhaps thats what you're looking for ?

The direction of the 2.5 kernel seems to me to be mainly (but not exclusively) targetting enterprise systems.