Re: [PATCH 07/16] kconfig-dynamic-frequency.diff

Jan Engelhardt
2007-04-01T19:03:42Z

On Apr 1 2007 14:52, Kyle Moffett wrote:
>
> On Apr 01, 2007, at 14:42:59, Jan Engelhardt wrote:
>> But I would have to ask: Why do we need 100/250/300/1000 if there
>> is anyway an input field for the user to enter - s/he should read
>> the help text for Known Good values, should not s/he?
>
> Actually, probably what should be done is make the "HZ_CUSTOM"
> option depend on EXPERIMENTAL / EMBEDDED / "EXPERT" /
> "I_KNOW_WHAT_THE_HELL_IM_DOING" or some other equivalent option,

EXPERIMENTAL is most often enabled by distributors.
And we are still missing our much-needed CONFIG_EXPERT :-(

> because a wrong choice for HZ has the potential to really screw up
> a system. For example, 10000+ would make most systems spend a
> significant portion of their time processing timer interrupts and

Point taken. Ehm, I already once tried making a 10000-Hz kernel
around 2.6.13-15 or so. It did not compile because some header files had
#error directives for HZ >= 1536. (jiffies.h:33 if you want
to know.) IIRC there also was another place somewhere in networking
code that #errors out at >8192.

Jan
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