Operating Systems » Linux Kernel

Linux kernel 2.6.32: virtualization, power management and more drivers

Less than a week after Linux kernel 2.6.31 was released, the kernel developers are beginning to submit changes and improvements across virtualization, power management, file systems and device driver code for the upcoming 2.6.32 version.

By Rodney Gedda | 16 September, 2009 12:43

Tags: drivers, linus torvalds, Linux, linux kernel, operating systems

Linux 2.6.28's five best features

While you were likely to be opening up Christmas presents, Linus Torvalds was giving Linux users around the world a special present: the release of the next major Linux kernel: Linux 2.6.28.

By Steven J. Vaughan-Nichols | 13 January, 2009 09:49

Tags: Linux

Making power policy just work

The kernel can't know if you want those low-priority processes to use all the CPU power on the system, or if you want them to pile up on one CPU and save power on the rest. Developers debate the best way to set the system's power rules.

Kernel space: The Tru64 Advanced Filesystem

On June 23, HP announced that it was releasing the source for the "Tru64 Advanced Filesystem" (or AdvFS) under version 2 of the GPL. This is, clearly, a large release of code from HP. What is a bit less clear is what the value of this release will be for Linux. In the end, that value is likely to be significant, but it will be probably realized in relatively indirect and difficult-to-measure ways.

Making desktop Linux work for business

Today's IT managers face tough choices. PCs that run fine today have an uncertain upgrade path, now that Microsoft has chosen to discontinue Windows XP. Upgrade costs associated with Vista, coupled with the ever-escalating cost of application licenses, make switching to desktop Linux an increasingly attractive option.

Kernel space: drivers that don't make the kernel scene

Arjan van de Ven's kernel oops report always makes for interesting reading; it is a quick summary of what is making the most kernels crash over the past week. It thus points to where some of the most urgent bugs are to be found. Sometimes, though, this report can raise larger issues as well. Consider the June 16 report, which notes that quite a few kernel crashes were the result of a not-quite-ready wireless update shipped by Fedora. Ingo Molnar was quick to jump on this report with a process-related complaint:

Kernel space: Interview with Andrew Morton

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.

Embedded developers keep watch on kernel bloat

Embedded Linux is getting a lot of attention these days. A new kernel.org mailing list, linux-embedded-archived here-has been set up, with discussions and patches already being posted. In addition, Paul Gortmaker and David Woodhouse have volunteered to be the "embedded maintainers" for the kernel to help coordinate the embedded Linux community. They graciously agreed to a joint email interview to shed some light on their new roles.

Kernel space: Using the firmware loader for static data

Some device drivers need firmware to load into the hardware at initialization time. The kernel firmware loader interface exists to support that functionality, but it requires help from user space which may not be available in all environments. David Woodhouse has proposed a patch that would eliminate that requirement so that more drivers can use the firmware loader rather than craft their own solution.

Kernel space: The big kernel lock strikes again

The AIM benchmark attempts to measure system throughput by running a large number of tasks (perhaps thousands of them), each of which is exercising some part of the kernel. Yanmin Zhang reported that his AIM results got about 40% worse under the 2.6.26-rc1 kernel. He took the trouble to bisect the problem; the guilty patch turned out to be the generic semaphores code. Reverting that patch made the performance regression go away - at the cost of restoring over 7,000 lines of old, unlamented code. The thought of bringing back the previous semaphore implementation was enough to inspire a few people to look more deeply at the problem.

Linux examined: Fedora 9

For many of us, our first painful introduction to old-school Linux installs came from installing early versions of Red Hat. Like most early Linux installs, it was a highly technical, highly finicky process that was best left to the experts.

Kernel space: Time to slow down?

All communities develop rituals over time. One of the enduring linux-kernel rituals is the regular heated discussion on development processes and kernel quality. To an outside observer, these events can give the impression that the whole enterprise is about to come crashing down. But the reality is a lot like the New Year celebrations the author was privileged enough to see in Beijing: vast amounts of smoke and noise, but everybody gets back to work as usual the next day.

Ksplice: kernel patches without reboots

The kernel developers are generally quite good about responding to security problems. Once a vulnerability in the kernel has been found, a patch comes out in short order; system administrators can then apply the patch (or get a patched kernel from their distributor), reboot the system, and get on with life knowing that the vulnerability has been fixed. It is a system which works pretty well.

E-paper support for Linux

The familiar CRT monitors or backlit LCD screens on our desks continuously consume power in order to hold an image. Electronic paper (e-paper) is different: power is only needed to change the image. Just like paper, e-paper is able to hold the image permanently without consuming any power. Displays using CRT, backlit LCD, plasma and OLED technologies are all emissive, meaning that they have to produce the photons that reach the eye. This implies that they have to compete in brightness with ambient lighting, which can result in eye strain. E-paper is the opposite: it is reflective, which makes it possible to read the display using ambient light even in the brightness of a hot sunny day.

Linux for the SMB market: slow, steady or both?

Everywhere you turn nowadays, another company is targeting the Small and Medium Business (SMB) marketplace. SMBs are growing, and represent a segment of the IT market that has not been fully exploited by many, including open source software vendors that boasted early successes with large enterprises.

A better ext4 filesystem for Linux

Linux's ext4 filesystem, the successor to ext3, may well be the filesystem many of us are using a few years from now. Things have been relatively quiet on that front - at least, outside of the relevant mailing lists - but the ext4 developers have not been idle. Some of their work has now come to the surface with Ted Ts'o's posting of the ext4 merge plans for 2.6.25.

Kernel space: a better btrfs

Chris Mason has recently released Btrfs v0.10, which contains a number of interesting new features. In general, Btrfs has come a long way since LWN first wrote about it last June. Btrfs may, in some years, be the filesystem most of us are using - at least, for those of us who will still be using rotating storage then. So it bears watching.

Open source and virtualization: Perfect match?

Virtualization is a hot data center technology that is capturing the attention of IT for its consolidation and cost saving potential. As was evidenced at the LinuxWorld conference in San Francisco last week, open source and Linux platforms are on the forefront of the trend. In fact, given licensing issues with proprietary software, the combination of inexpensive or free open-source software and virtualization platforms may be the most important vehicle to drive widespread Linux adoption in the data center. Here are seven need-to-know points when looking at open source virtualization technology.

The low-cost laptop offer Microsoft can't refuse

As the release of low-cost laptops based on Intel's upcoming Atom processor draws near, Microsoft is getting boxed into a corner. The software company plans to stop selling most Windows XP licenses after June 30, yet most of these low-cost laptops won't be powerful enough to run Vista when they arrive later this year.