Language Selection

English French German Italian Portuguese Spanish

Linux: Tuning CFS

Filed under
Linux

Nick Piggin used 'git bisect' to track a lmbench regression to the main CFS commit, leading to an interesting discussion between Nick and Ingo Molnar. Ultimately the regression was tracked down to the temporary configurability of the scheduler while it is tuned for optimal performance, "one reason for the extra overhead is the current tunability of CFS, but that is not fundamental, it's caused by the many knobs that CFS has at the moment." The solution, already coded but not yet merged in the mainline kernel "changes those knobs to constants, allowing the compiler to optimize the math better and reduce code size," and as a result result, "CFS can be faster at micro-context-switching than 2.6.22."

Ingo described the lmbench configuration in question as a "micro-benchmark", and noted that with a macro-benchmark better performance was more pronounced, "because with CFS the _quality_ of scheduling decisions has increased.

More Here




More in Tux Machines

How Linux containers can solve a problem for defense virtualization

As the virtualization of U.S. defense agencies commences, the technology’s many attributes—and drawbacks—are becoming apparent. Virtualization has enabled users to pack more computing power in a smaller space than ever before. It has also created an abstraction layer between the operating system and hardware, which gives users choice, flexibility, vendor competition and best value for their requirements. But there is a price to be paid in the form of expensive and cumbersome equipment, software licensing and acquisition fees, and long install times and patch cycles. Read more

Fedora 21: Linux fans will LOVE it - after the install woes

With Fedora's installer it isn't immediately clear what you need to do – or even that you need to do something – until you click each button and find out, which runs the "select your layout" and installs. It's not that bad; it's not like installing Arch, but it did leave me wondering “why?” Why not just go with the familiar, narrative-like sliding screen animation that, well, pretty much every other OS out there uses? Read more

Customers reporting interest in cloud, containers, Linux, OpenStack for 2015

As 2014 comes to a close and IT departments reflect on their initiatives heading into the new year, we asked a group of 115 Red Hat customers -- ranging from Fortune 500 companies to small businesses -- about their priorities for 2015. What we heard from the respondents is promising going into the new year: Budgets are increasing (or at least staying the same); Linux adoption is increasing; cloud deployments will be dominantly private or hybrid; OpenStack is hot; and interest in containers is emerging. Read more

Multi-Stream Transport 4K Monitors To Become Better Supported On Linux

For a number of months David Airlie at Red Hat has been working on DisplayPort Multi-Stream Transport (DP MST) handling for Linux. Keith Packard over at Intel is now playing with DP MST too for bettering modern 4K display support on Linux within X.Org Server based environments. Read more