Linux: CFS And Nice
The recently merged Completely Fair Scheduler changes how the Linux kernel handles scheduling priorities set with the nice command. Ingo Molnar explained that each level of nice adds or substracts 10% of CPU utilization, "the '10% effect' is relative and cumulative: from _any_ nice level, if you go up 1 level, it's -10% CPU usage, if you go down 1 level it's +10% CPU usage." Ingo noted that with the earlier scheduler the nice level was tied to the HZ, offering three examples in which HZ is set to 100, 250, and 300, "a nice +19 task (the most commonly used nice level in practice) gets 9.1%, 3.9%, 3.1% of CPU time on the old scheduler, depending on the value of HZ. This is quite inconsistent and illogical. This HZ dependency of nice levels existed for many years, and the new scheduler solves that inconsistency - every nice level will get the same amount of time, regardless of HZ."
- Login or register to post comments
- Printer-friendly version
- 2100 reads
- PDF version
More in Tux Machines
- Highlights
- Front Page
- Latest Headlines
- Archive
- Recent comments
- All-Time Popular Stories
- Hot Topics
- New Members
digiKam 7.7.0 is releasedAfter three months of active maintenance and another bug triage, the digiKam team is proud to present version 7.7.0 of its open source digital photo manager. See below the list of most important features coming with this release. |
Dilution and Misuse of the "Linux" Brand
|
Samsung, Red Hat to Work on Linux Drivers for Future TechThe metaverse is expected to uproot system design as we know it, and Samsung is one of many hardware vendors re-imagining data center infrastructure in preparation for a parallel 3D world. Samsung is working on new memory technologies that provide faster bandwidth inside hardware for data to travel between CPUs, storage and other computing resources. The company also announced it was partnering with Red Hat to ensure these technologies have Linux compatibility. |
today's howtos
|
Recent comments
1 year 11 weeks ago
1 year 11 weeks ago
1 year 11 weeks ago
1 year 11 weeks ago
1 year 11 weeks ago
1 year 11 weeks ago
1 year 11 weeks ago
1 year 11 weeks ago
1 year 11 weeks ago
1 year 11 weeks ago