Re: [PATCH] preset loops_per_jiffy for faster booting

[Adam Kropelin]

Dmitry Torokhov wrote:
> On Saturday 10 July 2004 01:28 pm, Adam Kropelin wrote:
>> + Note that on SMP systems the preset will be applied to all CPUs
>> + which will cause problems if for some reason your CPUs need
>> + significantly divergent settings.
>> +
>> + If unsure, set this to 0. An incorrect value will cause delays in
>> + the kernel to be wrong, leading to unpredictable I/O errors and
>> + other breakage. Although unlikely, in the extreme case this might
>> + damage your hardware.
>
> Note that it may also not work correctly on laptops that switch
> frequency when working on battery/AC. Also one needs to be careful
> when changing timesource (pit, tsc, pm, hpet). And always look out
> for timer code changes in next version of kernel.

Certainly many demons lurk around the corner, but embedded guys are used to
that.

> Does 250 ms worth all this pain?

On a desktop box, almost certainly not. On a massive SMP machine, maybe. On
an embedded system that is required to boot in a ridiculously short time,
absolutely.

--Adam

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