Messages in this thread | | | Subject | Re: How is user space notified of CPU speed changes? | From | Lee Revell <> | Date | Fri, 22 Oct 2004 19:25:58 -0400 |
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On Fri, 2004-10-22 at 13:40 -0600, Chris Friesen wrote: > Lee Revell wrote: > > > Seems like you are implying that any userspace app that needs to know > > the CPU speed is broken. Is this correct? > > No, we're saying that Intel's tsc implementation is broken. <grin> > > x86 really could use an on-die register that increments at 1GHz independent of > clock speed and is synchronized across all CPUs in an SMP box.
Like this? (posted to jackit-devel):
On Fri, 2004-10-22 at 18:20 -0500, Jack O'Quin wrote:
> On PowerPC, JACK uses the lower half of the 64-bit Timebase register, > which is accessible from user mode. This is better then the i386 > cycle counter, I believe. See: `config/cpu/powerpc/cycles.h', the > comment about only using it for SMP is bogus. We use this for both > MacOS X and Linux.
-- Lee Revell <rlrevell@joe-job.com>
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