Re: The "best" value of HZ

From: Alistair John Strachan (s0348365_at_sms.ed.ac.uk)
Date: 10/28/05

  • Next message: Fawad Lateef: "Re: 4GB memory and Intel Dual-Core system" 
    To: Claudio Scordino <cloud.of.andor@gmail.com>
Date:	Fri, 28 Oct 2005 03:31:21 +0100

    On Friday 28 October 2005 00:18, Claudio Scordino wrote:
    > Hi,
    >
    > during the last years there has been a lot of discussion about the
    > "best" value of HZ... On i386 was 100, then became 1000, and finally was
    > set to 250. I'm thinking to do an evaluation of this parameter using
    > different architectures.
    >
    > Has anybody thought to give the possibility to modify the value of HZ at
    > boot time instead of at compile time ? This would allow to easily test
    > different values on different machines and create a table containing the
    > "best" value for each architecture... At this moment, instead, we have to
    > recompile the kernel for each different value :(
    >
    > Do you think there would be much work to do that ?
    > Do you think it would be a desired feature the knowledge of the best value
    > for each architecture with more precision ?

    Google for "dynticks". There's obviously an overhead associated with HZ not
    being a constant (the compiler cannot optimise many expressions), but the
    feature is being worked on nonetheless. 

    -- 
Cheers,
Alistair.
'No sense being pessimistic, it probably wouldn't work anyway.'
Third year Computer Science undergraduate.
1F2 55 South Clerk Street, Edinburgh, UK.
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