Software:Timer coalescing
From HandWiki
Short description: Operating system feature to reduce CPU idle time
Timer coalescing is a computer system energy-saving technique that reduces central processing unit (CPU) power consumption by reducing the precision of software timers used for synchronization of process wake-ups, minimizing the number of times the CPU is forced to perform the relatively power-costly operation of entering and exiting idle states.[1]
Implementations of timer coalescing
- The Linux kernel gained support for deferrable timers in 2.6.22,[2][3] and controllable "timer slack" for threads in 2.6.28 allowing timer coalescing.[4][5]
- Timer coalescing has been a feature of Microsoft Windows from Windows 7 onward.[6]
- Apple's XNU kernel based OS X gained support as of OS X Mavericks.[7][8]
- FreeBSD supports it since September 2010.[9]
See also
- Advanced Configuration and Power Interface (ACPI)
- Advanced Programmable Interrupt Controller (APIC)
- High Precision Event Timer (HPET)
- HLT (x86 instruction)
- Interrupt coalescing
- Programmable interval timer
- Time Stamp Counter (TSC)
References
- ↑ Anderson, Nate (June 11, 2013). "How OS X "Mavericks" works its power-saving magic". Ars Technica. https://arstechnica.com/apple/2013/06/how-os-x-mavericks-works-its-power-saving-magic/. Retrieved 2014-03-22.
- ↑ "Linux Kernel 2 6 22". kernelnewbies.org. http://kernelnewbies.org/Linux_2_6_22. Retrieved 2014-03-22.
- ↑ "Add support for deferrable timers". 2007-05-08. https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=6e453a67510a17f01b63835f18569e8c3939a38c. Retrieved 2014-03-22.
- ↑ "time(7) - Linux manual page". Man7.org. http://man7.org/linux/man-pages/man7/time.7.html. Retrieved 2014-03-24.
- ↑ "prctl(2) - Linux manual page". Man7.org. http://man7.org/linux/man-pages/man2/prctl.2.html. Retrieved 2014-03-24.
- ↑ "Windows Timer Coalescing". Microsoft. January 20, 2009. http://www.microsoft.com/whdc/system/pnppwr/powermgmt/TimerCoal.mspx. Retrieved 2009-04-21.
- ↑ "OS X Mavericks - Advanced Technologies". Apple Inc.. https://www.apple.com/osx/preview/advanced-technologies.html. Retrieved 2014-03-22.
- ↑ "OS X Mavericks: Core Technologies Overview". Apple, Inc.. June 10, 2013. Archived from the original on June 26, 2013. https://web.archive.org/web/20130626042313/http://images.apple.com/osx/preview/docs/OSX_Mavericks_Core_Technology_Overview.pdf. Retrieved 2013-06-10.
- ↑ "Refactor timer management code". 13 September 2010. https://lists.freebsd.org/pipermail/svn-src-all/2010-September/028792.html.
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