Messages in this thread Patch in this message | | | Date | Tue, 21 Dec 2010 16:39:43 -0700 | From | Matthew Wilcox <> | Subject | [PATCH] Prevent users from disabling tickless |
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Disabling NO_HZ has a serious negative effect on performance -- an extra 70us per I/O. Prevent users from deselecting it.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig index f06a8a3..55b9a04 100644 --- a/kernel/time/Kconfig +++ b/kernel/time/Kconfig @@ -5,13 +5,9 @@ config TICK_ONESHOT bool config NO_HZ - bool "Tickless System (Dynamic Ticks)" + def_bool y depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS select TICK_ONESHOT - help - This option enables a tickless system: timer interrupts will - only trigger on an as-needed basis both when the system is - busy and when the system is idle. config HIGH_RES_TIMERS bool "High Resolution Timer Support" -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."
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