windows-server-2003/base/hals/intfilter

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* Interrupt-Affinity Filter

* 

* Author: Chris Prince ([email protected])

* Date:   Summer, 1999

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DESCRIPTION:

============

This Interrupt-Affinity Filter (IntFiltr) allows a user to change the 

CPU-affinity of the interrupts in a system.  



Using this utility, you can direct any device's interrupts to a specific 

processor or set or processors (as opposed to always sending interrupts to 

all the CPUs in the system).  Note that different devices _can_ have 

different interrupt-affinity settings.  This utility will work on any 

machine, regardless of what processor or interrupt controller or HAL is 

used.  



Obviously, this tool is only interesting for multi-processor machines.  







USAGE:

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There are 2 things that must be done in order to use IntFiltr.  These are: 



(1) Install the filter [only needs to be done once per machine]

(2) Configure the filter [whenever you want to change settings]







1. Installing the IntFiltr

--------------------------

To install IntFiltr, complete the following steps:



(a) Copy intfiltr.sys to your %SYSTEMROOT%\system32\drivers directory.

      [intfiltr.sys is located in the \Install subdirectory of this package]

(b) Update your registry to include the changes listed in intfiltr.reg

      To make these changes, you can just run 'regedit intfiltr.reg'.

      [intfiltr.reg is located in the \Install subdirectory of this package]

  



2. Configuring the IntFiltr

---------------------------

To configure IntFiltr, run intfiltr.exe (located in the \Config 

subdirectory of this package).  



First, highlight a device in the 'Devices' listbox.  Then you can use the 

'Add Filter' and 'Remove Filter' buttons to turn interrupt filtering on 

and off, respectively, for the selected device.  When IntFiltr is 

installed on a device, the string "InterruptAffinityFilter" will appear 

in the 'Upper Filters' listbox.  



You can use the 'Set Mask' button to set the CPU-affinity for the selected 

device's interrupts, or you can use the 'Delete Mask' button to remove a 

device's CPU-affinity mask from the registry.  Beware that if no 

CPU-affinity mask exists for a device, installing IntFiltr on a 

device will have no useful effect.  



The button marked "Don't Restart Device When Making Changes" is intended 

for advanced users.  You can use this button to change a device's filter 

settings without restarting the selected device.  Note that while this 

button is checked, any change you make will not take effect until the next 

time the device is restarted (which will usually not occur until the next 

reboot).  



IMPORTANT NOTE:  Although _all_ the machine's devices will appear in the 

'Devices' list, it only makes sense to install IntFiltr on top of devices 

that have interrupt resources.  To see which devices have interrupt 

resources, you can go into Device Manager and select View -> Resources By 

Type.