On Tue, 9 Jul 2013, Ian Smith wrote:
On Sat, 6 Jul 2013 20:09:46 -0600, Warren Block wrote:
> On Sun, 7 Jul 2013, Ian Smith wrote:
>
> > So even if cpu_running_mark were 100% (-r100), anything busier than 25%
> > of our example 75MHz would shift to maximum freq immediately, where the
> > load will likely plummet to just a few percent, way less than the 25%
> > (at -r100) needed to keep it at that freq; ie it will most likely hunt.
>
> It may do that, but if so it's doing it more quickly than is visible running
> powerd -a hyper -n hyper -v.
Apart from some possible under-the-hood adjustment by thermal control in
an over-temperature situation (?) and /etc/rc.d/power_profile poking the
freq on AC/battery changes (not applicable to yours), as far as I know
the only thing that adjusts freqs is powerd itself. So no, it's not
hunting for you. But then, due to you having disabled p4tcc and
acpi_throttle, your lowest speed is 1600, only 1/2.25 x 3600, a far cry
from the up to 32:1 sort of ranges seen with p4tcc etc enabled.
What I'm concerned about is what happens engaging your hyper mode with
out-of-the-box settings, ie with p4tcc or acpi_throttle enabled as by
default. Would you care to find out? :) I have no means to do so.
> /boot/loader.conf:
> hint.p4tcc.0.disabled="1"
> hint.acpi_throttle.0.disabled="1"
> hw.acpi.cpu.cx_lowest="C3"
Commenting those entries out gives:
dev.cpu.0.freq_levels: 3601/300000 3600/300000 3500/300000 3400/300000
3300/300000 3200/300000 3100/300000 3000/300000 2900/300000 2800/300000
2700/300000 2600/300000 2500/300000 2400/247000 2300/224000 2200/202000
2100/182000 2000/163000 1750/142625 1600/91000 1400/79625 1200/68250
1000/56875 800/45500 600/34125 400/22750 200/11375
dev.est.0.freq_settings: 3601/300000 3600/300000 3500/300000 3400/300000
3300/300000 3200/300000 3100/300000 3000/300000 2900/300000 2800/300000
2700/300000 2600/300000 2500/300000 2400/247000 2300/224000 2200/202000
2100/182000 2000/163000 1600/91000
dev.p4tcc.0.freq_settings: 10000/-1 8750/-1 7500/-1 6250/-1 5000/-1
3750/-1 2500/-1 1250/-1
With only that change and powerd running in hyper mode, it subjectively
feels slower to start things.
> I've routinely used the first two since first reading about them, I think in
> another post by Kevin.
Indeed, Kevin's been chewing on this bone for quite some time :) but I
don't know if there's any PR + simple patch that may attract attention?
I also don't know if the situation is the same on AMD CPUs, or others.
> /etc/rc.conf:
> powerd_flags="-a hyper -n hyper"
Still on 9.1 at least,
#define DEFAULT_ACTIVE_PERCENT 75
#define DEFAULT_IDLE_PERCENT 50
#define DEFAULT_POLL_INTERVAL 250 /* Poll interval in milliseconds */
So hyper mode will select max freq if load at 1600MHz is > 75/4 = 18.75%
after 250mS. I use 200mS and there's no impact on powerd CPU usage even
at my idle 733MHz; your responsiveness may benefit from using say 100mS?
Interesting point. 100mS is a perceptible lag.
It occurs to me that CPU load is really a poor predictor of what is
happening on an interactive session. powerd ought to have a wakeup
signal. On a keypress or mouse move or some other type of user input,
powerd would jump to the highest frequency of the current profile. It
does not matter as much how it decides to drop back down.
Using devd to switch powerd profiles would be interesting. powerd would
have to be able to switch profiles while running, I think. Maybe
startup cost is not that high.
> This is an i5, with the "3601" being turbo mode.
With that beast I'm amazed you can really notice slower responsiveness
w/ 4 CPUs @ 1600MHz, but then I get by with a P3-M at 1133/733MHz :)
Some would say I'm more particular about it than most people. I just
say I want it faster. :)
It would be interesting to see cpu.0.freq_levels, est.0.freq_settings
and the p4tcc.0 settings - and whether it hunts - with default tuning on
some sort of lightish load - perhaps a big find like on the daily runs?
Timing 'periodic daily' now with a full cache and powerd not running:
995.53 real 28.15 user 132.17 sys
With 'powerd -a hyper -n hyper -v > /tmp/powerd.log':
2322.06 real 58.72 user 305.22 sys
Load varied enough that it would drop to 200MHz quite often. Picking a
random part of the log:
load 0%, current freq 200 MHz (26), wanted freq 200 MHz
load 0%, current freq 200 MHz (26), wanted freq 200 MHz
load 0%, current freq 200 MHz (26), wanted freq 200 MHz
load 11%, current freq 200 MHz (26), wanted freq 200 MHz
load 0%, current freq 200 MHz (26), wanted freq 200 MHz
load 0%, current freq 200 MHz (26), wanted freq 200 MHz
load 10%, current freq 200 MHz (26), wanted freq 200 MHz
load 4%, current freq 200 MHz (26), wanted freq 200 MHz
now operating on AC power; changing frequency to 3601 MHz
load 55%, current freq 200 MHz (26), wanted freq 3601 MHz
changing clock speed from 200 MHz to 3601 MHz
now operating on AC power; changing frequency to 200 MHz
load 4%, current freq 3601 MHz ( 0), wanted freq 200 MHz
changing clock speed from 3601 MHz to 200 MHz
load 4%, current freq 200 MHz (26), wanted freq 200 MHz
now operating on AC power; changing frequency to 3601 MHz
load 20%, current freq 200 MHz (26), wanted freq 3601 MHz
changing clock speed from 200 MHz to 3601 MHz
now operating on AC power; changing frequency to 200 MHz
load 3%, current freq 3601 MHz ( 0), wanted freq 200 MHz
changing clock speed from 3601 MHz to 200 MHz
load 4%, current freq 200 MHz (26), wanted freq 200 MHz
now operating on AC power; changing frequency to 3601 MHz
load 21%, current freq 200 MHz (26), wanted freq 3601 MHz
changing clock speed from 200 MHz to 3601 MHz
now operating on AC power; changing frequency to 200 MHz
load 0%, current freq 3601 MHz ( 0), wanted freq 200 MHz
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