Linux desktop users can look forward to a faster experience in addition to USB 3.0 support and new Firewire drivers With the next version of the Linux kernel, 2.6.31, due for release soon.
The kernel developers have been working on improvements to desktop interactivity, particularly when it’s under memory pressure since the last release, version 2.6.30, in June.
Desktop applications can experience long and noticeable pauses when the application’s code path jumps to a part of the code that is not cached in memory and needs to be read from the disk, which is slower.
However, recent kernel memory management scalability work can result in a desktop environment with poor interactivity as applications become unresponsive too easily.
In version 2.6.31, some heuristics have been used to make it much harder to move the “mapped executable pages” out of the list of active pages, according to Kernelnewbies.org.
“The result is an improved desktop experience; benchmarks on memory tight desktops show clock time and major faults reduced by 50 per cent, and pswpin numbers (memory reads from disk) are reduced to about one-third. That means X desktop responsiveness is doubled under high memory pressure.”
Furthermore, memory flushing benchmarks in a file server shows the number of major faults going from 50 to 3 during 10 per cent cache hot reads.
Linux founder Linus Torvalds, first developed the operating system for his desktop and it rose to prominence as a commodity Unix server.
However, adoption of Linux on PCs and notebooks has remained niche compared with Windows and only became more of a mainstream alternative in recent years.
Estimates vary wildly as to how many Linux desktops are in use today, but according to market share data from Net Applications, the proportion of Linux desktops peaked at 1.17 per cent in May 2009 and has since dropped to 0.94 per cent in August.
The advent of Windows 7 in October may drive Linux’s desktop market share down even further.
It’s not all doom and gloom for the penguin, however, as the improvement in kernel memory management, X.org display server developments, graphics driver updates and advancements in the two main desktop environments – GNOME and KDE – all continue to enhance the Linux desktop ecosystem.
Another improvement coming with 2.6.31 is kernel mode-setting support for ATI Radeon graphics cards.
Kernel mode-setting moves graphics mode initialisation from the X server startup process to the kernel, enabling faster user switching and a more seamless startup experience.
Peripheral developments that will also improve the Linux desktop experience include support for the new USB 3.0 specification and a new Firewire stack.
Intel has been working USB 3.0 device support for hardware that implements the eXtensible Host Controller Interface (xHCI) 0.95 specification.
USB 3.0, or SuperSpeed USB, ups the theoretical maximum data transfer rate to 4Gbps.
No xHCI hardware is available yet, but the kernel drivers have been tested under the Fresco Logic host controller prototype.
For Firewire, 2.6.31 brings improved support of fine-grained access permission policies for application programs in userspace, IP networking with the new driver stack, and support for Firewire disks larger than 2TB.
“No longer marked as ‘experimental’ in the kernel configuration menu, distributors who provided the older ieee1394 driver stack so far are encouraged to build and install both driver stacks,” according to the project.
The last release candidate of the new Linux kernel was 2.6.31-rc8 on August 28.
hbailla, Sunday, September 6, 2009