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How to get the cause of high CPU usage by DPC / Interrupt
Posted 25 November 2011 - 08:17 AM
Posted 29 November 2011 - 01:35 PM
I even succeeded to run xperf under WinXP (this is something I wanted to share with the community to give something back):
- first I extracted "xperf.exe" and "xperfctl.dll" from the "wpt_x86.msi" (you can use 7zip to do this)
- i copied this to a temporary folder
- i started a dos box and changed to that folder
- i ran the xperf logging like described and stopped it like described
I did NOT succeed viewing/debugging the etl-file in WinXP, but: I just copied the "*.etl" to a Win7 computer (where I have a normal wpt-Installation running) and doubleclicked the *.etl-file to find results...
It seems to work and I could identify a troublemaker on the WinXP machine (see attachmed file, etl was created with xperf in WinXP and diagnose ran in xperfview@Win7, thats why there's the aero window style).
dpc_xp.jpg 82.16KB 11 downloads
So thank you for this thread and I hope someone could benefit from my WinXP-trials with this tool...
Posted 29 November 2011 - 02:35 PM
Posted 29 November 2011 - 02:58 PM
Edited by imp666, 30 November 2011 - 02:15 AM.
Posted 02 December 2011 - 02:53 AM
Would it be easier if I just PM you my scan to look at?
Many thanks for any help you can provide.
Edited by BearandNeets, 02 December 2011 - 03:02 AM.
Posted 02 December 2011 - 06:52 AM
Posted 04 December 2011 - 07:31 PM
Can anyone help? It causes ripping and popping audio wise in anything cpu intensive like skyrim or deus ex...
Posted 05 December 2011 - 05:53 AM
If this doesn't help, compress and upload the trace to mediafire.com and post a link here.
Posted 20 December 2011 - 09:11 AM
The ntoskrnl.exe seems to have some high values.
In Process Explorer I do see a 5-6% CPU usage for Intrerrupts.
I do have a Intel i7 @ 2.0Ghz and 12gig of ram.
What happens? My mouse starts to slug.
Edited by h3x00r, 20 December 2011 - 09:11 AM.
Posted 20 December 2011 - 09:12 AM
Posted 12 January 2012 - 09:42 AM
Posted 12 January 2012 - 12:52 PM
Posted 16 January 2012 - 10:40 PM
Posted 17 January 2012 - 06:53 AM
Posted 17 January 2012 - 03:58 PM
ATA Channel 0
ATA Channel 1
ATA Channel 3
ATA Channel 4
ATA Channel 5
Intel ® 6 Series/C200 Series Chipset Family 6 Port SATA AHCI Controller - 1C02
I'm not sure if the above has anything to do with the problem, but figured I'd list it anyway.
Posted 17 January 2012 - 05:27 PM
Posted 17 January 2012 - 11:42 PM
I actually arrived to this thread after googling why NT Kernel & System was having CPU usage spikes on my new computer (~25% every minute or so, constantly).
I just got this Dell laptop a few days ago and CPU usage issues started happening yesterday. I did update several drivers, including those of the graphics cards and the BIOS from the Dell site.
I did everything you recommended on your post and I can't figure out what the results mean, could you help me out? I can't relate the results to a specific driver.
I'm attaching a screenshot of the Sampling Summary Table showing the culprit (ntoskrnl.exe).
If it helps I should tell you this:
- The CPU usage spikes won't happen on safe mode.
- A few days ago I shut down my computer and it started installing Windows Update files, I was in a hurry so I physically shut it down, next time when I tried to log in it crashed before the Windows start screen. I restarted it and it went fine.
Could it be that I have a corrupted ntoskrnl.exe?
Edited by Damascus, 17 January 2012 - 11:59 PM.
Posted 18 January 2012 - 07:55 AM
Posted 18 January 2012 - 02:32 PM
Posted 18 January 2012 - 07:38 PM
hmm, you don't really have a DPC/Interrupt issue. But the good question is why the kernel takes 25% cpu usage. Does it also happen if you remove AVG from your system?
Yep, I actually installed AVG after it started happening so I could scan for a possible virus or something.
I just noticed something interesting though. The 25% CPU usage only happens when I'm connected to my home Internet connection (wireless), if I'm connected at college it doesn't happen at all, it stays at 0% CPU constantly. It's odd and it's driving me insane, since the computer is new I'm considering returning it to its Factory state and see if it helps.
I'm not sure if it's possible to save a CPU usage graph using Process Explorer, but I'm attaching a screenshot. All those spikes are from System, they have the same 25 - 28% magnitude and they all last around the same time.
EDIT: Just checked System properties using Process Explorer, under Threads it shows that the thread causing the CPU spikes is called "ntoskrnl.exe!KeAcquireInStackQueuedSpinLockAtDpcLevel+0x1e0"
Trying to figure out what that means.
Edited by Damascus, 18 January 2012 - 08:15 PM.
Posted 19 January 2012 - 06:18 AM
xperf -start perf!GeneralProfiles.InBuffer && timeout -1 && xperf -stop perf!GeneralProfiles.InBuffer DetailedTrace.etlto trace more details. How do you connect at college? Also with Wireless like at home or with LAN? Do you use the latest driver for your Intel® Centrino® Wireless-N 1030?
Posted 19 January 2012 - 12:44 PM
I'm having trouble loading the symbols. I've installed xperf with the .NET Framework 4 SDK Web installer, so the process wasn't quite the same as on the page you linked to in your first post, but I installed WPT and Debugging tools under Common Utilities and WPT under Redistributable Packages. Might not have needed all those but wasn't sure.
Anyway, that gives a Start Menu shortcut, Windows SDK 7.1 Command Prompt, so I used that and created the trace with xperf. Then I open it with WPA and change the NT_SYMBOL_PATH to srv*C:\symbols*http://msdl.microsoft.com/download/symbols tick Load Symbols and click on Summary Table, but everything's listed under Unknown.
I might already have enough information from LatencyMon for you to go on though.
I'm running Win7 x64 Ultimate SP1 on a MSI 990FXA-GD80 motherboard with Phenom II X4 955 processor and 8GB DDR3.
I first found I was having dpc latency problems that were being caused by Outpost Security Suite, so I uninstalled that and installed Comodo Firewall instead. I also had to kill/disable the nusb3mon.exe utility, which brought the max execution time for USBPORT.SYS down from 1.3ms to 0.38ms.
Later, I installed VMware Workstation (as I was having problems doing some things in Virtualbox so wanted to see if VMware worked better) and noticed problems again. I reduced them by disabling the two NICs that it installed, but had to disable all it's services as well to completely sort it out, so I uninstalled it.
However, I'm still having problems. I notice if I open a browser (IE or Iron Portable) the execution time for ndis.sys jumps up to 0.5-0.8ms. Although LatencyMon reports that my system is still OK to play video with latency around 500us, I get spikes much higher (around 1100us) and ndis.sys can hit 1.35ms-2.8ms and then LatencyMon reports that my system isn't OK. With Outpost SS, tcpip.sys was the problem (around 0.7ms with spikes every 5 seconds), followed by ataport.sys and USBPORT.SYS.
After getting rid of OSS, I tried disabling the two Standard Dual Channel PCI IDE Controllers (one of which is off a PCI standard PCI-to-PCI bridge) that don't have anything connected, the 1394 Controller, the AMD 6950 HD Audio, the two USB 3 Controllers, three Standard Enhanced PCI to USB Host Controllers and three Standard OpenHCD USB Host Controllers, but was still having a problem with USBPORT.SYS hitting 1.3ms:
I then disabled nusb3mon.exe which brought it down to 0.38ms and moved my KVM from a USB3 port (running at USB2 I imagine considering what I'd disabled) to a USB2/SATA combo port, which brought it down to 0.25ms but I still had problems with ataport.sys:
Then I transferred my KVM to a normal USB2 port, after which USBPORT.sys and ataport.sys didn't go above 0.25ms although uninstalling OSS seemed to have caused ndis.sys to increase from 0.03ms to 0.28ms
However, since installing/uninstalling VMware I'm now having problems with ataport.sys again. I've still got all the devices listed above disabled, and still only have things plugged in the normal USB2 ports.
I've just unplugged my USB hub (with only an Xbox360 controller plugged in) so that only my KVM is connected to a USB port, which may have brought the ataport.sys execution time down somewhat, but the latency's still rather high.
Edited by doveman, 19 January 2012 - 12:49 PM.
Posted 19 January 2012 - 02:04 PM
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