Jeremy Andrews of KernelTrap has today announced the availability of the new Linux Kernel Job Board service on his site. Here's the original announcement:

I am pleased to announce that KernelTrap has partnered with Specialty Job Markets to offer a unique Linux kernel job board for our readers. It is completely free to submit your resume, which will then be personally reviewed and matched with current and future employment opportunities. If you're an employer, it's also free to post jobs. Jobs and resumes that are posted to our boards are individually reviewed and matched by a professional recruiter, not a computer program, offering quality results with a personal touch. The contact information you provide is kept confidential and is only visible to our dedicated recruiter.

Referencing the post Nvidia Linux driver 100.14.11 and Linux kernel 2.6.23. Here I have reported the patches for older versions of Nvidia drivers. The procedure to follow is the same described in the above document.

The nonprofit Linux Foundation has unveiled the Linux Weather Forecast, a Web site aimed at giving people a better sense of the status of specific Linux kernel projects. The Foundation created the forecast site by teaming up with Jonathan Corbet, a Linux kernel developer and writer, who's also executive editor of the LWN.net Linux and free software news site.

The forecast is already live and tracks work in the Linux developer community likely to be included in the operating system's kernel and in major distributions of the open-source software, or both. The forecast provides summaries on work in areas such as core Linux kernel development, virtualization and containers, file systems, security, networking, and support for hardware.

Well, they're not working together. Unless you're not willing to tweak it a little bit. So, out of the box, you won't be able to test brand new Linux CFS scheduler, merged in the 2.6.23-rc1 release, if you drive your Nvidia card with the proprietary driver. I guess that's what we get for running binary drivers.

The dust has yet to settle from the recent announcements that Linux will switch it's process scheduler, but we're already bombarded with interesting news that the upcoming 2.6.23 kernel release will also feature no less than two new virtualization frameworks.

The smaller one is called lguest, "a simple hypervisor for Linux on Linux. Unlike kvm it doesn't need VT/SVM hardware. Unlike Xen it's simply 'modprobe and go'. Unlike both, it's 5000 lines and self-contained.". The lguest patches are written and maintained by Rusty Russell who explains, "lguest is designed to be a minimal hypervisor for the Linux kernel, for Linux developers and users to experiment with virtualization with the minimum of complexity. Nonetheless, it should have sufficient features to make it useful for specific tasks, and, of course, you are encouraged to fork and enhance it.". (commit)

The Linux kernel process scheduler, as you know it, has been completely ripped out and replaced with a completely new one called Completely Fair Scheduler (CFS). How fair it will be, remains to be seen, but in the meantime here's what its original creator Ingo Molnar has to say on the subject:

80% of CFS's design can be summed up in a single sentence: CFS basically models an "ideal, precise multi-tasking CPU" on real hardware.

"Ideal multi-tasking CPU" is a (non-existent :-)) CPU that has 100% physical power and which can run each task at precise equal speed, in parallel, each at 1/nr_running speed. For example: if there are 2 tasks running then it runs each at 50% physical power - totally in parallel.

If you're a heavy user of the Linux VGA console, you'll like this feature. Recent 2.6 kernels have added support for soft scrollback. This feature enables you to have much bigger scrollback buffer than the standard console has, at the price of slightly slower console output.

Judging by this commit, CFQ (Complete Fair Queuing) I/O scheduler will become the default one in the upcoming 2.6.18 kernel. For a long time, anticipatory scheduler has been the default, although even back in late 2004 there was some thinking about replacing it with CFQ. And it seems the time has finally come. CFQ scheduler has been gaining adoption since then, to the point that it's the default I/O scheduler for RHEL 4, Suse, and other distros.

Ingo Molnar has announced the first release of his "lock dependency correctness validator" kernel debugging feature.

From the announcement:

The lock validator "observes" and maps all locking rules as they occur dynamically (as triggered by the kernel's natural use of spinlocks, rwlocks, mutexes and rwsems).
Whenever the lock validator subsystem detects a new locking scenario, it validates this new rule against the existing set of rules. If this new rule is consistent with the existing set of rules then the new rule is added transparently and the kernel continues as normal. If the new rule could create a deadlock scenario then this condition is printed out.

One of the more interesting patches for the linux kernel lately has been Wu Fengguang's adaptive readahead patchset, currently at version 12. Talking about its performance benefits Wu says: "besides file servers and desktops, it is recently found to benefit postgresql databases a lot.".

So I decided to do a simple benchmark to see what difference would adaptive readahead make in my case. The idea was to test a very simple database query (random select) to the PostgreSQL database and see how it performs through time (while the memory is being primed with data from disk).

This patch, courtesy Rick Lindsley, resolves long standing problem with disk statistics counters in 2.4 kernels.

Because of the bug in kernel, the counters would occasionally incorrectly report negative values. The patch has been tested against 2.4.24, but will probably apply on other versions, too. Thanks Rick!