From: jeff@jgarrett.org (Jeff Garrett)
To: peng huang <huangpeng.linux@gmail.com>
Cc: linux-kernel@vger.kernel.org, Len Brown <lenb@kernel.org>,
linux-acpi@vger.kernel.org
Subject: Re: acpi_idle: Very idle Core i7 machine never enters C3
Date: Tue, 26 Jan 2010 08:59:51 -0600 [thread overview]
Message-ID: <20100126145951.GA4987@jgarrett.org> (raw)
In-Reply-To: <1264509660.29891.7.camel@huang-laptop>
On Tue, Jan 26, 2010 at 09:41:00PM +0900, peng huang wrote:
> Hi,
> can you show me the file /proc/acpi/processor/CPU*/power.
> and are you sure your cpu usage is 0 or nearly zero.
Yea, I'm pretty sure my cpu usage is nearly zero. powertop shows fewer
than 20 wakeups per second, shows 99% C2 residency, top shows 100% idle,
perf top shows acpi_idle_enter_simple as the most common function
(~50%). Very little is running on the box, and I've compiled out the
heavier parts of the kernel (such as USB)...
(It still has ordinary userspace running, e.g. udev & hal, and still has
sshd and network traffic, as examples.)
This is all consistent with a very idle machine, I think.
> this is the info of my laptop(using core 2 processors):
> powertop's output:
> Cn Avg residency P-states (frequencies)
> C0 (cpu running) (10.6%) 2.00 Ghz 1.9%
> C0 0.0ms ( 0.0%) 1.67 Ghz 0.1%
> C1 mwait 0.0ms ( 0.0%) 1333 Mhz 0.0%
> C2 mwait 0.0ms ( 0.0%) 1000 Mhz 98.0%
> C3 mwait 1.1ms (89.4%)
Yea, my laptop also (also core 2) has 700-1000 wakeups/sec and spends
greater than 80% of its time in C3... That's partly why I'm curious
about what my core i7 desktop is doing.
> and power things:
> huang@huang-laptop:~$ cat /proc/acpi/processor/CPU0/power
> active state: C0
> max_cstate: C8
> maximum allowed latency: 2000000000 usec
> states:
> C1: type[C1] promotion[--] demotion[--]
> latency[001] usage[00002364] duration[00000000000000000000]
> C2: type[C2] promotion[--] demotion[--]
> latency[001] usage[00070662] duration[00000000000006013816]
> C3: type[C3] promotion[--] demotion[--]
> latency[017] usage[04774185] duration[00000000010838418152]
>
> you can see C3 with powertop,so i think your BIOS has enabled Deep
> C-state.
Here's my power files...
/proc/acpi/processor/CPU0/power:
active state: C0
max_cstate: C8
maximum allowed latency: 2000000000 usec
states:
C1: type[C1] promotion[--] demotion[--] latency[001] usage[00001470] duration[00000000000000000000]
C2: type[C2] promotion[--] demotion[--] latency[017] usage[00234416] duration[00000000017165798539]
C3: type[C3] promotion[--] demotion[--] latency[017] usage[00000000] duration[00000000000000000000]
/proc/acpi/processor/CPU1/power:
active state: C0
max_cstate: C8
maximum allowed latency: 2000000000 usec
states:
C1: type[C1] promotion[--] demotion[--] latency[001] usage[00000481] duration[00000000000000000000]
C2: type[C2] promotion[--] demotion[--] latency[017] usage[00090169] duration[00000000017188463157]
C3: type[C3] promotion[--] demotion[--] latency[017] usage[00000000] duration[00000000000000000000]
/proc/acpi/processor/CPU2/power:
active state: C0
max_cstate: C8
maximum allowed latency: 2000000000 usec
states:
C1: type[C1] promotion[--] demotion[--] latency[001] usage[00000418] duration[00000000000000000000]
C2: type[C2] promotion[--] demotion[--] latency[017] usage[00068874] duration[00000000017193805291]
C3: type[C3] promotion[--] demotion[--] latency[017] usage[00000000] duration[00000000000000000000]
/proc/acpi/processor/CPU3/power:
active state: C0
max_cstate: C8
maximum allowed latency: 2000000000 usec
states:
C1: type[C1] promotion[--] demotion[--] latency[001] usage[00001356] duration[00000000000000000000]
C2: type[C2] promotion[--] demotion[--] latency[017] usage[00362752] duration[00000000017156707397]
C3: type[C3] promotion[--] demotion[--] latency[017] usage[00000000] duration[00000000000000000000]
>
> -huang
>
> 2010-01-26 (火) の 02:47 -0600 に Jeff Garrett さんは書きました:
> > Hi,
> >
> > I was trying to chase down a theory that my desktop machine (a core i7)
> > is running warm (the fan sounds like it's at full speed all the time,
> > and I think it's not always acted this way -- hence the theory).
> >
> > powertop is never showing it spending any time in C3...
> >
> > I compiled a kernel without USB/sound/radeon, and ran without X. I was
> > able to get the wakeups/sec down below 20, but no time is spent in C3.
> >
> > sysfs looks to agree with powertop here (time = 0 on C3):
> > /sys/devices/system/cpu/cpu0/cpuidle/state0/desc: CPUIDLE CORE POLL IDLE
> > /sys/devices/system/cpu/cpu0/cpuidle/state0/latency: 0
> > /sys/devices/system/cpu/cpu0/cpuidle/state0/name: C0
> > /sys/devices/system/cpu/cpu0/cpuidle/state0/power: 4294967295
> > /sys/devices/system/cpu/cpu0/cpuidle/state0/time: 457
> > /sys/devices/system/cpu/cpu0/cpuidle/state0/usage: 59
> > /sys/devices/system/cpu/cpu0/cpuidle/state1/desc: ACPI FFH INTEL MWAIT 0x0
> > /sys/devices/system/cpu/cpu0/cpuidle/state1/latency: 1
> > /sys/devices/system/cpu/cpu0/cpuidle/state1/name: C1
> > /sys/devices/system/cpu/cpu0/cpuidle/state1/power: 1000
> > /sys/devices/system/cpu/cpu0/cpuidle/state1/time: 308177
> > /sys/devices/system/cpu/cpu0/cpuidle/state1/usage: 3975
> > /sys/devices/system/cpu/cpu0/cpuidle/state2/desc: ACPI FFH INTEL MWAIT 0x10
> > /sys/devices/system/cpu/cpu0/cpuidle/state2/latency: 17
> > /sys/devices/system/cpu/cpu0/cpuidle/state2/name: C2
> > /sys/devices/system/cpu/cpu0/cpuidle/state2/power: 500
> > /sys/devices/system/cpu/cpu0/cpuidle/state2/time: 873440787
> > /sys/devices/system/cpu/cpu0/cpuidle/state2/usage: 239038
> > /sys/devices/system/cpu/cpu0/cpuidle/state3/desc: ACPI FFH INTEL MWAIT 0x20
> > /sys/devices/system/cpu/cpu0/cpuidle/state3/latency: 17
> > /sys/devices/system/cpu/cpu0/cpuidle/state3/name: C3
> > /sys/devices/system/cpu/cpu0/cpuidle/state3/power: 350
> > /sys/devices/system/cpu/cpu0/cpuidle/state3/time: 0
> > /sys/devices/system/cpu/cpu0/cpuidle/state3/usage: 0
> >
> > This may be a complete red herring, but I added some printk logic to
> > acpi_idle_bm_check(), and it is getting called often, but bm_status is
> > always 1. [I infer from this that the idle logic is trying to go into
> > C3, but this check is stopping it... Unless I misread something.]
> >
> > Is this expected behavior or is this a legitimate problem?
> >
> > How might I investigate this further?
> >
> > Attaching dmesg, /proc/cpuinfo, powertop -d output.
> >
> > Thanks,
> > Jeff Garrett
>
>
> --
> peng huang <huangpeng.linux@gmail.com>
>
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next prev parent reply other threads:[~2010-01-26 15:00 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-26 8:47 acpi_idle: Very idle Core i7 machine never enters C3 Jeff Garrett
2010-01-26 12:41 ` peng huang
2010-01-26 14:59 ` Jeff Garrett [this message]
2010-01-27 13:27 ` peng huang
2010-02-05 16:22 ` Jeff Garrett
2010-01-26 21:45 ` Andi Kleen
2010-02-05 16:09 ` Jeff Garrett
2010-02-05 17:45 ` Len Brown
2010-02-05 20:53 ` Jeff Garrett
2010-04-27 2:40 ` Philip Langdale
2010-04-27 7:26 ` Len Brown
2010-04-27 15:41 ` Philip Langdale
2010-04-27 12:47 ` Jeff Garrett
2010-04-30 14:57 ` Philip Langdale
2010-04-30 16:25 ` Len Brown
2010-04-30 17:44 ` Matthew Garrett
2010-04-30 18:35 ` Philip Langdale
2010-05-25 5:43 ` Len Brown
2010-05-25 5:59 ` Yu, Luming
2010-05-25 12:39 ` Matthew Garrett
2010-05-25 12:43 ` Matthew Garrett
2010-05-25 15:33 ` Len Brown
2010-05-25 18:55 ` Matthew Garrett
2010-07-21 21:31 ` [PATCH] ACPI: make acpi_idle Nehalem-aware Len Brown
2010-07-22 0:53 ` Venkatesh Pallipadi
2010-07-22 7:47 ` Andi Kleen
2010-07-22 15:57 ` Len Brown
2010-07-22 21:21 ` [PATCH] ACPI: skip checking BM_STS if the BIOS doesn't ask for it Len Brown
2010-07-22 21:40 ` [PATCH] ACPI: create "processor.bm_check_disable" boot param Len Brown
2010-07-26 7:24 ` Andi Kleen
2010-07-27 0:19 ` Len Brown
2010-07-27 11:28 ` Andi Kleen
2010-07-28 18:58 ` Len Brown
2010-07-22 21:25 ` [PATCH] ACPI: make acpi_idle Nehalem-aware Iain
2010-07-22 21:53 ` Iain
2010-07-22 22:01 ` Len Brown
2010-07-23 12:40 ` Iain
2010-08-03 6:55 ` Pavel Machek
2010-08-03 7:05 ` Andi Kleen
2010-05-25 12:37 ` acpi_idle: Very idle Core i7 machine never enters C3 Matthew Garrett
2010-05-25 15:40 ` Len Brown
2010-07-22 5:34 ` Len Brown
2010-02-01 14:10 ` Pavel Machek
2010-02-05 16:30 ` Jeff Garrett
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