Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754785Ab0A0N1Z (ORCPT ); Wed, 27 Jan 2010 08:27:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754489Ab0A0N1V (ORCPT ); Wed, 27 Jan 2010 08:27:21 -0500 Received: from mail-yx0-f188.google.com ([209.85.210.188]:45662 "EHLO mail-yx0-f188.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754481Ab0A0N1U (ORCPT ); Wed, 27 Jan 2010 08:27:20 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=CXl1w9rFdh4ENGKoaam3XumYyw49RjbuoaagJfZyaCEgoyB2g0fgAgy3Y3ZPH39+ST Nli7roKx23KzDmZ9LHNQOliSdEGyMvbnR3Dg3XNDWXQzfycMvSMBBOLBFrXq79yxP6Nt svfNWCQf2VeEJmCV8ZUb+xZ5rQrKKgR39lKN8= Subject: Re: acpi_idle: Very idle Core i7 machine never enters C3 From: peng huang To: Jeff Garrett Cc: linux-kernel@vger.kernel.org, Len Brown , linux-acpi@vger.kernel.org, huangpeng.linux@gmail.com In-Reply-To: <20100126145951.GA4987@jgarrett.org> References: <20100126084740.GA5265@jgarrett.org> <1264509660.29891.7.camel@huang-laptop> <20100126145951.GA4987@jgarrett.org> Content-Type: text/plain; charset="UTF-8" Date: Wed, 27 Jan 2010 22:27:17 +0900 Message-ID: <1264598837.32649.9.camel@huang-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7911 Lines: 164 2010-01-26 (火) の 08:59 -0600 に Jeff Garrett さんは書きました: > 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. yes,you processor is always in c2,it does means your system is nearly ilde. > > 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. So I think it is a core i7 thing.I have heard that some intel cpu have a problem when in c2-state,maybe that is why you cpu cant enter c3-state. I think there is some configuration about deep c-state in the bios,may be you can try it(it cannot solve this problem...). And in some bios there is a enhanced idle state configuration ,but i dont known if it is the reason why the cpu cannot enter c3-state.You can try it anyway. With disable the deep c-state you BIOS will not give c3-info to the OS,then you would see there is no c3-state in the OS. > > 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 > > -- peng huang -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/