Deferred Procedure Calls

I have looked and i am still not sure what DPCs are used for and if i am on a stand alone system, do i need it ?

 

In case it helps....what causes you to ask this ?

 

Bubba...i saw it running while looking at Process Explorer

 

Interrupts and DPCs
On Windows NT-based systems Process Explorer shows two artificial processes: Interrupts and DPCs. These processes reflect the amount of time the system spends servicing hardware interrupts and Deferred Procedure Calls (DPCs), respectively. High CPU consumption by these activities can indicate a hardware problem or device driver bug. To see the total number of interrupts and DPCs executed since the system booted add the Context Switch column. Another sometimes useful metric is the number of interrupts and DPCs generated per refresh interval, which you see when you add the CSwitches Delta column.


hope this helps T

 

Interesting......thank you.......what are Deferred Procedure Calls and being on a stand alone computer, can i safely turn it/them off ?

 

Was the info you saw similar to the below pic ?

Notice that it is not actually a process....similar to the one above it Interrupts(Hardware Interrupts)

 

Rainwalker,
They are an integral and low level part of Windows and cannot be turned off
They are different to Remote Procedure Calls (which also cannot be turned off) and it was probably Remote Procedure Calls that you were thinking about

Some "light" reading
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dndevice/html/IRQL_Sched.asp
http://msdn.microsoft.com/library/d..._07529fa6-0954-4b27-b610-99f465d2fbf3.xml.asp

Regards

 

One can see RPC's via Process Explorer

 

Hi gottadoit,

Please explain what happens when the Remote Procedure Call (RPC) service is stopped or disabled? Is this not the same as "turned off"? Re: WinXP!

For example, Start->Run->services.msc->Ok
Check status of Remote Procedure Call (RPC) and Remote Procedure Call (RPC) Locator services.

If they are started, right-click on either one, select Properties, and if you are an Administrator account, you can modify the start type to Manual or Disabled.

-- Tom

 

@ Bubba.........yes, similar
@ Gottadoit.........yup, RPCs is what i was concerned with
Thanks all for getting back

 

lotuseclat79,
I probably should have made the point that RPC "could possibly" be turned off but shouldn't because it is required for Windows to work

Have a read about it on the (archive of the) black viper site
Or the other aptly titled article "I disabled Remote Procedure Call (before I read your advice) and I my computer is broke! What do I do?"

Regards

 

Thanks...no problems

 

Hi gottadoit,

My point was that it was entirely possible to turn off RPC, and asserting that RPC "could possibly" be turned off only muddies one's understanding. What one needs to understand is what services are impacted when RPC is turned off, so the services that depend upon RPC are either disabled or scaled down in their capabilities, i.e. deprecated, or need to be started manually to reacquire other functionality. For example, although I run with RPC automatically started, I set to manual the other services needed for Windows Update and manually start those services every month for the updates from MS - not a good example to support my assertion below.

My assertion is that it is entirely possible to run Windows without RPC, although at somewhat of a deprecated level as far as services are concerned.

For example, the following services dependent on RPC are running automatically on my WinXP Pro SP2 system, while the remaining services that depend on RPC are either disabled or set to manual in my configuration:
COM + Event System
Crypotgraphic Services
Error Reporting Service
Fax
Help and Support
Logical Disk Manager
Network Connections
Print Spooler
Protected Storage
Security Accounts Manager
Security Center
System Restore Service
Task Scheduler
Windows Audio
Windows Management Instrumentation
Windows User Mode Driver Framework

Note: this list is 16 in number as opposed to 43 system level services in total for Windows XP Pro SP2 depending on RPC - i.e. not counting 3rd party system level services which with RPC (not started) would probably prevent them from working as advertised.

That said, Windows can work at a deprecated level, you just may not be able to do everything you want to do.

-- Tom

 

Somewhat on the same topic, an interesting article by Sysinternals' Mark Russinovich: Running Windows with No Services.

Nick