Re: [patch 00/21] high resolution timers / dynamic ticks - V2
From: Valdis . Kletnieks
Date: Mon Oct 02 2006 - 09:03:24 EST
On Sun, 01 Oct 2006 22:59:01 -0000, Thomas Gleixner said:
> the following patch series is an update in response to your review.
First runtime results - no lockups or other severe badness in a half-hour or so
of running.
-mm2-hrt-dynticks5 shows severe clock drift issues if you run 'cpuspeed'.
Using speedstep-ich as a kernel built-in, and cpuspeed is invoked as:
cpuspeed -d -n -i 10 -p 10 50 -a /proc/acpi/ac_adapter/*/state
If cpuspeed drops the CPU speed from the default 1.6Ghz down to 1.2Ghz (the
only 2 speeds available on this core), the system clock proceeds to lose
about 15 seconds a minute. I haven't dug further into why yet. (If the system
is busy so cpuspeed keeps the processor at 1.6Ghz, the clock doesn't drift
as much - so it looks like a "when speed is 1.2Ghz" issue...)
I'm also seeing gkrellm reporting about 25% CPU use when "near-idle" (X is up
but not much is going on) when that's usually down around 5-6%. I need to
collect some oprofile numbers and investigate that as well.
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