Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH] Prevent users from disabling tickless | Date | Wed, 22 Dec 2010 00:46:23 +0100 |
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On Wednesday, December 22, 2010, Matthew Wilcox wrote: > > 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>
OTOH, it causes some systems to not work at all still. Sadly.
Thanks, Rafael
> 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" > >
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