Messages in this thread | | | Subject | Default HZ value for X86 | From | Alok Kataria <> | Date | Mon, 27 Apr 2009 16:07:10 -0700 |
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Hi,
I was wondering why do we still have the default HZ value as 1000 for the x86 kernels.
arch/x86/configs/i386_defconfig:CONFIG_HZ=1000 arch/x86/configs/x86_64_defconfig:CONFIG_HZ=1000
With the highres timer implementation it was planned to move away from relying on high timer interrupt frequency for applications requiring precise high resolution timer's.
This quote in the timer/hrtimers.txt also mentions that we should be able to decrease the frequency of the timeout subsystem, which I assume would mean reducing HZ value.
--------------------------------------------------------------------- "Another potential benefit is that such a separation allows even more special-purpose optimization of the existing timer wheel for the low resolution and low precision use cases - once the precision-sensitive APIs are separated from the timer wheel and are migrated over to hrtimers. E.g. we could decrease the frequency of the timeout subsystem from 250 Hz to 100 HZ (or even smaller)." ---------------------------------------------------------------------
So, are there still any concerns that keep us from lowering the default HZ value down to 250/100 for mainline ?
Thanks, Alok
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