Re: Re: many lost ticks, clock drifts problems also with debian smp kernel?
On Fri, Dec 09, 2005 at 03:06:16PM +0100, remi.delmas.3000@free.fr wrote:
> what is a TSC?
Time Stamp Counter or something like that. It is a counter in the cpu
that can theoretically be used as a fast way to keep track of time.
Most modern CPUs have one. Some count at full cpu clock rate, some
count slower. Depends on the design. On multi cpu systems, they are
often not in sync, but initially it was thought that dual core AMDs
would have them in sync, but that isn't true apparently due to frequency
scaling and power management stuff changing the counter speed.
> what does the clock=pmtmr bootparam do?
I think it changes what device the kernel uses to keep track of time.
The is the power management timer, the hpet (high performance event
timer), the TSC, and a few other choices. Some are faster to read, some
are more accurate, and it all depends on the type of system which ones
you can even rely on.
> what is HPET_TIMER=y ?
> what is PM_TIMER=y ?
That would be the two I mentioned above.
> and what is LKML?
Linux Kernel Mailing List. See vger.kernel.org.
Len Sorensen
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