Linux Kernel Update Improves Event Monitoring

Developers promise a stable version of Kernel 2.6.13 within a few weeks, with additions that include the Xtensa architecture.

The next stable update of the Linux kernel will bring advances in file system event monitoring, the Xtensa architecture, and a set of system calls that allows users to load another kernel from the currently executing Linux kernel.

While the 2.6.13 –rc (release candidates) are currently being tested, the stable version is expected to be released in the next few weeks, kernel developers told eWEEK.

In fact, Linus Torvalds, the "father" of Linux, this week told kernel developers on the Linux Kernel Mailing List that he "really wanted to release a 2.6.13, but theres been enough changes while weve been waiting for other issues to resolve that I think its best to do a -rc7 first," he said.

Most of the -rc7 changes were "pretty trivial, either one-liners or affecting some particular specific driver or unusual configuration," he said.

The 2.6.13 kernel will bring some significant changes, including the addition of Inotify, a file system event-monitoring mechanism designed to serve as an effective replacement for Dnotify, which was the de facto file-monitoring mechanism supported in older Linux kernels.

Inotify is a fine-grained, asynchronous mechanism suited to a variety of file-monitoring needs, including security and performance.

Also included will be the Xtensa architecture, which is a configurable, extensible and synthesizable processor core and the first microprocessor architecture designed specifically to address embedded SOC (System-On-Chip) applications.

Also included will be Kexec, a set of system calls that allows the user to load another kernel from the currently executing Linux kernel, and Kdump, a kexec-based crash dumping mechanism for Linux, said Greg Kroah-Hartman, a Linux kernel developer at Novell Inc. in Portland, Ore.

Also in the cards is an implementation of "executeI in place" for a specific s/390 usage, kernel maintainer Andrew Morton told eWEEK.

The devfs (device file system) will be disabled in this release, which also contains an enhancement to the Complete Fair Queuing disk I/O scheduler, which permits separate processes to have different I/O priorities, similar to nice levels for CPU prioritization, Morton said.

The Linux vendors are also likely to quickly adopt many of these new kernel features in their consumer and enterprise distributions. Donald Fischer, a product manager at Red Hat Inc., told eWEEK that the kernel includes "the latest and greatest kernel releases in our Fedora Core community project on an ongoing basis, and 2.6.13 will appear in a Fedora Core release, coming soon."

/zimages/1/28571.gifFor an eWEEK Labs review of Fedora Core 4, click here.

Fischer said Red Hat would also include most new kernel features that are of use to its customers in future major releases of its enterprise products. "For example, features of 2.6.13 will be included in our future Red Hat Enterprise Linux Version 5 solution," he said. Red Hat Enterprise Linux 4 was released earlier this year.

Fischer said the company would also selectively back-port certain functions from recent community kernel releases to its enterprise product.

"In general, this is limited to new hardware platform support features. The reason [for this] is that our enterprise products favor stability for more conservative enterprise customers, versus Fedora, which targets the latest and greatest technology for developers and enthusiasts," Fischer said.

Coming in future stable Linux kernel releases will be the Xen virtualization technology; Fuse, which makes it possible to implement a fully functional file system in a user-space program; and version 2 of the OCFS (Oracle Cluster File System), which will be the first clustering component to be added to the public kernel, Novells Kroah-Hartman said.

But some technologies that have been expected to be in the kernel going forward may now not make it after all, Morton said, including the Reiser 4 local file system, about which he said, "I dont know when Reiser4 will be mergeable—there are issues."

Red Hats GFS (Global File System), which is commonly used in clusters of enterprise applications to provide a consistent file system image across the server nodes, allowing the cluster nodes to simultaneously read and write to a single shared file system, may also not ever find its way into the kernel. "Thats all in flux," Morton said.

Next Page: Incorporating the kernel into the enterprise.