A new patch for the kernel scheduler promises huge improvements in system speed under load. Initial tests show in fact that the new solution represents a drastic improvement.
Those who followed the development of the kernel in the last few weeks or months, could not overlook that the focus of development to the improvement in speed shifted. So the most important change in the next version of the kernel , the removal of the “Big Kernel Lock” (BKL). The BKL was introduced in 1996 with the extension of the kernel for SMP capabilities to control the concurrent access of two processors on the same data structures. This method scales poorly, however, on many processors and threads, and makes the system supports. By removing the locks, the system is effective more quickly, because it eliminated many forced breaks, the areas in front of a concurrent access protected.
Now another patch makes the circle of developers for ecstasy. Based on an idea by Linus Torvalds declining revision of the scheduler Mike Galbraith implemented by automatic task groups. The aim of just 200 lines long implementation is the reduction of latency and, consequently, a higher execution speed of the system.
The results of the new solution can be quite impressive. According to a measurement of the average latency Galbraith was formerly 9000 of microseconds to less than 150 microseconds. The maximum latency was the new solution at just 4.16 ms, whereas in the original nor was almost 43 ms. Similar values have seen other developers. Torvalds himself speaks of a “vast improvement” that one with “naked eye” problems, without any test can detect. In his case, he had run only “make-j64″ while scrolling through his e-mails.
The developers are therefore confident that the work of Galbraith is one of those that represent a drastic improvement for the core. As various studies show, she brings not only theoretical advantages, but makes the desktop on load much faster. According to Torvalds, the new feature is therefore classified as a “killer feature”. You see the speed increase, which brings with it a new function, one can fully agree with him.
