Re: kernel / userspace HZ

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Jesper Juhl schreef:
On 21/01/2008, Christian Boon <chris.boon@xxxxxxxxx> wrote:
Hello,

For my ARM processor (PXA255) i use kernel 2.6.22 and a kernel HZ value
of 1000.
[snip]
Am i doing something wrong here? Is this value converted to some sort of
userspace HZ?
I have tried it on x86 also and it gives the same behaviour.


In old kernels the HZ value (in both kernel- and user-space) was 100
without the ability to change this.
When the kernel added the option of other HZ values this was
implemented as kernel-space only and the HZ value exposed to
user-space was fixed at 100. This was done to avoid breaking
applications that assumed a fixed HZ of 100.
So, while the kernel may tick at 100, 250, 1000 or some other HZ
values (or even be tick less), user-space will always see HZ as being
100.

Ok thanks,
is there another way to receive the tick counter in userspace?

Chris

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