topic How to run code on a specific CPU in Software Archive

How to run code on a specific CPU

mguptamel — Tue, 11 Jan 2011 03:17:12 GMT

Hi all,

I have multi-core processor (Core -2 duo) which has 4 logical processors. I would like to switch processor to run the code. For example,

;Assuming code is running on CPU-0
mov eax, ecx

; I want to switchto CPU-1 (don't know how to go about it)
mov ebx, eax

; Switch back to CPU-0 here
mov ecx, eax

Note: Above is just a sample code. My intentions are to learn how to switch b/w CPU's and to set code affinity to a specific CPU

Help appreciated

Regards
Gupta

How to run code on a specific CPU

TimP — Thu, 13 Jan 2011 13:45:57 GMT

This question might be handled better on the threading forum, but you should specify your OS and more about what you wish to accomplish.

How to run code on a specific CPU

mguptamel — Thu, 13 Jan 2011 23:09:09 GMT

Thanks Tim. I will re-ask this question in threading forum.

I was writing a test driver in Windows OS, and came across KeSetProcessorAffinity function which was forcing the code to run on a specific processor. After the call, the code somehow started running on CPU [0-3]. That made me think what could be logic behind this function call. And that was my original question.

After reading through Intel documentation, I know how interrupt routines can be executed on a dedicated processor (by setting destination bits in IOREDIRECT table - IOAPIC), but I don't know exactly how a running thread can be executed on a specific processor.