UNIX for Dummies Questions & Answers

We can use "pbind" to bind a process to a specific processor. But it requires the id of the process to be binded, meaning we have to do the binding after starting that process.

So how can we bind a process to a specific processor while we start that process. Say we are working on a Sun's UltraSparc T1 that has 8 cores and each core supports 4 threads (i.e., we have 32 virtual processors), and we would like to start 32 different applications naming app_0, app_1, ..., app_31 on the available 32 virtual processors. In other word, we hope to do the mapping:
app_0 -> virtual_processor_0
app_1 -> virtual_processor_1
...
app_31 -> virtual_processor_31.

How can we achieve that? Many thanks.

You'll need psrset to dedicate a processor. pbind won't do that.
pbind is what is used to bind a process to a processor. I was under the impression that was what was initially asked. psrset is for multiple processors.

The reason I am not keen on pbind, etc is that on large SunFires that use DR, this causes problems. If a process is bound to a processor, DR fails. On something that can do DR, unlike the 4500 (I know it can be done but why even try as it is bound to fail), this has caused me some heartache in a previous lifetime.

It was very embarressing when you are the Sun Champion for DR and you explain the benefits of DR to customers and then go to show them and it fails. Why did it fail, because someone has bound a process to a processor and I did not check it as it was a scripted DR to give extra processing power during certain times. The script was running in the SC of a 15K so it did not check the processors that were being used in the individual domains. It was bad enough getting passed RT processes.

So, now you know why I don't like it.

the following example binds processes 204 and 223 to processor 2:

#pbind -b 2 204 223
process id 204: was 2, now 2
process id 223: was 3, now 2

If you're askign abt query bindings, then, It demonstrates that process 1 is bound to processor 0, process 149 has at least one LWP bound to CPU3, and process 101 has no bound LWPs.

#pbind -q 1 149 101
process id 1: 0
process id 149: 3
process id 101: not bound

Querying LWP Bindings
The following example queries bindings of LWPs. It demonstrates that LWP 1 of process 149 is bound to CPU3, and LWP 2 of process 149 is not bound.

# pbind -q 149/1-2
lwp id 149/1: 3
lwp id 149/2: not bound

Thanks for your reply incredible.

But I guess this does not completely solve the problem. My question is how to bind a process to a processor right after the process is STARTED rather than binding it after a while using its process id?

Say what we would like to do is to start running "app_1" at "virtual_processor_1" right after we type "app_1" at terminal. Rather than looking at the process id of "app_1" and binding it after it has been started, how can we bind it at the beginning?

Then I guess you should come out with a script to automate that for you. By default, you can't do that with whatever functionality/commands that are available