Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753399AbYHLSdp (ORCPT ); Tue, 12 Aug 2008 14:33:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751767AbYHLSdg (ORCPT ); Tue, 12 Aug 2008 14:33:36 -0400 Received: from nf-out-0910.google.com ([64.233.182.191]:33486 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751655AbYHLSdf (ORCPT ); Tue, 12 Aug 2008 14:33:35 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:content-type:date:message-id:mime-version:x-mailer :content-transfer-encoding; b=K89nRCogPbjhbilGWyVBSTMSVHUsjhP8j98irOlRF3ybBXTuFTQLg3XP0loqWjY0VD GIHR6Vzohgy4Ul0qd0M7zfEe4WG8WJivjpRAoqpxsVrUzmfVuKAMuqhMl+u0KL2AHbui y+6DF4PcoD61/V7lLzneJKJGu74Yxf6In2Hjk= Subject: Timer unstability on when using C2 and deeper sleep states (Dell Latitude XT) From: Milan Plzik To: linux-kernel@vger.kernel.org Content-Type: text/plain Date: Tue, 12 Aug 2008 20:33:28 +0200 Message-Id: <1218566008.13866.41.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5571 Lines: 159 Good day, This e-mail will be a bit longer, as I will describe everything I was able to find out about $subj. I'm not 100% sure that the issue is what it seems to be (not even sure I'm posting to correct mailing list), so if you see I did something wrong, please tell me. Also please, Cc: me, as I'm not (yet, I was not able to find out how) subscribed to this mailing list. I started to experiment with Linux on Dell Latitude XT, actually with 2.6.26 (for more info see [1]). The system seems to be more or less operational, when booting without any special arguments, but sometimes it hangs for few seconds with no reason. This becomes more apparent when e.g. playing movie (player sometimes stops for really long while), and is also apparent when using powertop, which tells me I had 20000 wakeups/s (yes, twenty thousand) per second, although sum of wakeups from the topmost wakeup causes does not reach 2000. Sometimes, however, this number goes down to reasonable values, but only for a while. I spent some time experimenting with linux kernel parameters; first with clocksource, where with all possible sources (but jiffies, which seemed to work) were having the same problem. With nohz=off parameter the computer was stable (but it did not enter power saving states), and after trying processor.max_cstate=1, computer was stable as well (any higher state causes instability) and powertop was returning meaningful values. Any attempts I made failed, so I'll welcome any suggestion, I have never seen something like this before. Best regards, Milan Plzik [1] My configuration follows: # uname -a Linux tiny 2.6.26-gentoo #18 SMP Tue Aug 12 12:40:57 CEST 2008 x86_64 Intel(R) Core(TM)2 CPU U7600 @ 1.20GHz GenuineIntel GNU/Linux # grep -e HZ -e HPET -e RTC -e IDLE -e CPUFREQ /usr/src/linux/.config |grep -v "not set" CONFIG_ARCH_HAS_CPU_IDLE_WAIT=y CONFIG_NO_HZ=y CONFIG_HPET_TIMER=y CONFIG_HPET_EMULATE_RTC=y CONFIG_HZ_1000=y CONFIG_HZ=1000 CONFIG_X86_ACPI_CPUFREQ=y CONFIG_X86_ACPI_CPUFREQ_PROC_INTF=y CONFIG_CPU_IDLE=y CONFIG_CPU_IDLE_GOV_LADDER=y CONFIG_CPU_IDLE_GOV_MENU=y CONFIG_HPET=y CONFIG_HPET_MMAP=y CONFIG_RTC_LIB=y CONFIG_RTC_CLASS=y CONFIG_RTC_HCTOSYS=y CONFIG_RTC_HCTOSYS_DEVICE="rtc0" # RTC interfaces CONFIG_RTC_INTF_SYSFS=y CONFIG_RTC_INTF_PROC=y CONFIG_RTC_INTF_DEV=y CONFIG_RTC_INTF_DEV_UIE_EMUL=y # I2C RTC drivers # SPI RTC drivers # Platform RTC drivers CONFIG_RTC_DRV_CMOS=y # on-CPU RTC drivers # cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Core(TM)2 CPU U7600 @ 1.20GHz stepping : 2 cpu MHz : 800.000 cache size : 2048 KB physical id : 0 siblings : 2 core id : 0 cpu cores : 2 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr lahf_lm bogomips : 2402.19 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: processor : 1 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Core(TM)2 CPU U7600 @ 1.20GHz stepping : 2 cpu MHz : 800.000 cache size : 2048 KB physical id : 0 siblings : 2 core id : 1 cpu cores : 2 apicid : 1 initial apicid : 1 fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr lahf_lm bogomips : 2400.00 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: # lspci 00:00.0 Host bridge: ATI Technologies Inc Device 7930 00:01.0 PCI bridge: ATI Technologies Inc Device 7932 00:04.0 PCI bridge: ATI Technologies Inc Device 7934 00:06.0 PCI bridge: ATI Technologies Inc Device 7936 00:07.0 PCI bridge: ATI Technologies Inc Device 7937 00:13.0 USB Controller: ATI Technologies Inc SB600 USB (OHCI0) 00:13.1 USB Controller: ATI Technologies Inc SB600 USB (OHCI1) 00:13.2 USB Controller: ATI Technologies Inc SB600 USB (OHCI2) 00:13.3 USB Controller: ATI Technologies Inc SB600 USB (OHCI3) 00:13.4 USB Controller: ATI Technologies Inc SB600 USB (OHCI4) 00:13.5 USB Controller: ATI Technologies Inc SB600 USB Controller (EHCI) 00:14.0 SMBus: ATI Technologies Inc SB600 SMBus (rev 14) 00:14.1 IDE interface: ATI Technologies Inc SB600 IDE 00:14.2 Audio device: ATI Technologies Inc SB600 Azalia 00:14.3 ISA bridge: ATI Technologies Inc SB600 PCI to LPC Bridge 00:14.4 PCI bridge: ATI Technologies Inc SB600 PCI to PCI Bridge 01:05.0 VGA compatible controller: ATI Technologies Inc Device 7942 03:01.0 CardBus bridge: Texas Instruments PCIxx12 Cardbus Controller 03:01.1 FireWire (IEEE 1394): Texas Instruments PCIxx12 OHCI Compliant IEEE 1394 Host Controller 03:01.3 SD Host controller: Texas Instruments PCIxx12 SDA Standard Compliant SD Host Controller 09:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5756ME Gigabit Ethernet PCI Express 0b:00.0 Network controller: Broadcom Corporation BCM4310 USB Controller (rev 01) -- 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/