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davodavo
Posts: 39
Registered: ‎02-22-2008
Location: San Francisco, CA USA
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Access Connections 5.62 on WinXP pro SP3 high CPU utilization (SVCHOST)

Noticed a new issue with AC v5.62.

 

When AC is trying to search for WiFi access points or connect to them, the SVCHOST process goes completely nuts, with 100% CPU utlization for up to a minute.  Nearly freezes the computer...

 

Any ideas on what may be causing this?

 

The problem gets much worse when the system is resuming from a suspend or hibernate cycle.  This is occasionally accompanied by an error message from AC indicating that "there's no compatible WIFI device in the sytem."

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Herik
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Registered: ‎07-17-2009
Location: Slovakia
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Re: Access Connections 5.62 on WinXP pro SP3 high CPU utilization (SVCHOST)

Hi,
svchost is a tool, that is running the "Windows Zero configuration" windows service, which is needed for the correct workflow of the Access Connection application.
So just check if you have it started and set to automatic.

Also check if you have up to date following applications/drivers:
- Power Management driver
- Power Manager
- Hotkey utility

Thease needs to be up to date, as they are suporting the Access connection in his functionality and a missmatch in the versions might cause similar issues.

I'm testing the AC 5.62 version on my own X301 with XP SP3 EN for quite a while and cannot experience such situation. I'm also testing it on T410 and T500 with Vista and Win7 as OS and cannot see this kind of behaviour.

Can you please tell me whether are you not using some other Network connection tool, that might interfer with Access Connection, or similar application? I would like to reproduce this situaiton in our lab, so in case you can provide any info, then that would be great.
Also please let me know, if this happens only by onf kind of Wifi connection, or it happens, also when you try to connect to WPA, or WPA2,.... ?

Cheers

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davodavo
Posts: 39
Registered: ‎02-22-2008
Location: San Francisco, CA USA
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Re: Access Connections 5.62 on WinXP pro SP3 high CPU utilization (SVCHOST)

Hi Herik,

 

Thanks for your prompt and detailed reply.

 

Here's what I'm running:

   Win XP Pro SP3 with all the latest patches and Norton AV

   Intel PRO/1000 MT ethernet controller (original)

   Atheros 11b/g wireless LAN mini PCI adaptor (original)

   AC 5.62 // Build 81CX57WW

   Power Mgt Driver  1.60.04

   Battery Maximizer / Power Management 1.38

   Hotkey 3.09.0000

 

No other Wireless/network controller software is intalled besides AC.  Hotkey functions properly, power mgt functions properly.

 

Doesn't seem to make any difference between encrypted/unencrypted.  Also, connection from ethernet seems fairly clumsy (like, the connection is already made, but AC keeps trying to re-make it...which wipes out the connection every 5 minutes).  Does seem that something is stepping on something else...

gan
Posts: 906
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Registered: ‎11-26-2008
Location: Norway
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Re: Access Connections 5.62 on WinXP pro SP3 high CPU utilization (SVCHOST)

[ Edited ]

Just curious, do you see the same problem if you temporary disable all the real time scanning features of the antivirus before you search for or connect to wlan?

 

I'm asking because i had a similar problem in the past while using AC and it was caused by the antivirus scanning a logfile created/modified when using AC. There was a lot of lines written to that logfile each time i switched profiles in AC and just like in your case it was the svchost process and not the antivirus process that used a lot of CPU.

 

-gan

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davodavo
Posts: 39
Registered: ‎02-22-2008
Location: San Francisco, CA USA
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Re: Access Connections 5.62 on WinXP pro SP3 high CPU utilization (SVCHOST)

Oh, good idea.

 

I turned Norton AV off and the CPU / SVCHOST utilization didn't change appreciably (still >60 seconds, or 100,000,000,000 CPU cycles doing something.

 

Some extra data for you:

  • the SVCHOST process is quite small, memory footprint of <10 MB
  • the CPU usage explosion is worst immediately **after** the wireless connection has been satisfactorily completed by AC
  • the issue seems to get worse with long up-times and frequent connect/disconnect cycles. 

Using process explorer, the specific SVCHOST that goes nuts is the one that handles the DNS client (dnscache) service...it doesn't handle anything else.  Are there any parameters or things I should be looking for that can make it behave better?

 

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davodavo
Posts: 39
Registered: ‎02-22-2008
Location: San Francisco, CA USA
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Re: Access Connections 5.62 on WinXP pro SP3 high CPU utilization (SVCHOST)

[ Edited ]

Discovered some DNS client registry keys that may be the crux of the issue.  They were all set to 0, which makes the DNS cache daemon have to work a lot harder.

 

Look at this page for explanation of what they ought to be...don't forget, these are DECIMAL, not HEX values...and a reboot is required for them to take effect.  Am trying them now....

gan
Posts: 906
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Registered: ‎11-26-2008
Location: Norway
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Re: Access Connections 5.62 on WinXP pro SP3 high CPU utilization (SVCHOST)


davodavo wrote:

Using process explorer, the specific SVCHOST that goes nuts is the one that handles the DNS client (dnscache) service...it doesn't handle anything else.  Are there any parameters or things I should be looking for that can make it behave better?

 


Well that reminds me of another problem i had in the past :smileyhappy:

 

I had some leftovers in the registry from an old network interface and because of that there was a lot of registry activity. I started out using process explorer and found the same svchost process that had to do with DNS. Then i checked the threads tab in process explorer for that process to find the thread and checked using the stack for that thread. Had to install Windows debugging tool to get the information i wanted and change some settings in process explorer. That's when i figured there was a lot of registry activity. Then i used process monitor and could easily see the key that was read over and over again. I deleted that key and problem solved.

 

So you could try process montor as well to see if there is any strange activity going on. Like something related to DNS doing the same thing over and over again. If that doesn't help you might have to install windows debugging tool to get more information from process explorer.

 

-gan

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davodavo
Posts: 39
Registered: ‎02-22-2008
Location: San Francisco, CA USA
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Re: Access Connections 5.62 on WinXP pro SP3 high CPU utilization (SVCHOST)

OK, by changing the DNS client parameters, the SVCHOST is a lot more reasonable.  Maybe 10 seconds of 100% CPU right after disconnect, and 45 seconds after connect. 

 

Not exactly a barn-burner, but a good 40% improvement.

 

Ideas?  I don't have access to developer tools to chase down individual registry entries that are being banged on endlessly by DNSclient...

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davodavo
Posts: 39
Registered: ‎02-22-2008
Location: San Francisco, CA USA
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Re: Access Connections 5.62 on WinXP pro SP3 high CPU utilization (SVCHOST)

Any recollection of the key name?

gan
Posts: 906
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Registered: ‎11-26-2008
Location: Norway
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Re: Access Connections 5.62 on WinXP pro SP3 high CPU utilization (SVCHOST)

[ Edited ]

No cannot remember the name except i belive it was pretty cryptic in this format:

{4D36E973-E325-11CE-BFC1-08002BE10318}

 

Also it was somewhere under "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet".

 

If you had the same problem the key name is most likely not identical anyway, but the same format. Using regmon it was pretty easy to spot seeing the same thing over and over again.

 

To make sure you don't break anything it could be a good idea to backup the part of the registry before you delete it in case you find something. Also take a close look so it's not obvious it shouldn't be deleted.

 

-gan