Re: high power consumption in recent kernels

From: Norbert Preining
Date: Thu Sep 30 2010 - 02:59:15 EST


> The following line is different, the new code remove the nohz_ratelimit
> from irq_exit(). That may resolve your system too many interrupts
> issue.
>
> + arch_needs_cpu(cpu)|| (inidle && nohz_ratelimit(cpu))) {

That is a very nice one ..., first time I came down
with inactive laptop, lowest brightness, down to below 8W:
Cn Avg residency P-states (frequencies)
C0 (cpu running) ( 1.1%) Turbo Mode 0.0%
C0 0.0ms ( 0.0%) 2.54 Ghz 0.0%
C1 mwait 0.0ms ( 0.0%) 1.60 Ghz 0.0%
C2 mwait 0.3ms ( 0.8%) 800 Mhz 99.9%
C6 mwait 16.7ms (98.2%)

Wakeups-from-idle per second : 81.3 interval: 15.0s
Power usage (ACPI estimate): 7.9W (11.0 hours)

Top causes for wakeups:
23.8% ( 18.1) kworker/0:0
14.0% ( 10.7) [ahci] <interrupt>
13.4% ( 10.2) [kernel scheduler] Load balancing tick
6.6% ( 5.0) syndaemon
5.5% ( 4.2) Xorg
5.5% ( 4.2) [extra timer interrupt]
4.6% ( 3.5) [acpi] <interrupt>

Very nice, with activity and bluetooth and internet over bluetooth
I am back at 10.3W, but that is also fine.

Anything else you need to know (kernel was latest git, -rc6 AFAIR).

Best wishes

Norbert
------------------------------------------------------------------------
Norbert Preining preining@{jaist.ac.jp, logic.at, debian.org}
JAIST, Japan TeX Live & Debian Developer
DSA: 0x09C5B094 fp: 14DF 2E6C 0307 BE6D AD76 A9C0 D2BF 4AA3 09C5 B094
------------------------------------------------------------------------
The main reception foyer was almost empty but Ford
nevertheless weaved his way through it.
--- Ford making his way out of Milliways whilst under the
--- influence of enough alchol to make a rhino sing.
--- Douglas Adams, The Hitchhikers Guide to the Galaxy
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/