CPU Binding
Hello Everyone, I just wanted to clarify how does IDS determine the number of processors a UNIX box have? Our new server(Sun Fire E6900) uses the UltraSPARC IV processor, which is using the Chip Multithreading(CMT) technology. Through CMT, 20 additional virtual processors are spawned apart from the 20 physical processors that the server have. Running the mpstat will actually show 40 cpus though the prtdiag only shows 20 cpus. My issue is I want to bind not only the physical processor but the virtual processors as well. I tried binding 26 processors but I'm getting "VPCLASS 'cpu' not enough physical procs for affinity" message. Is there any way to tell IDS that the server have more CPU than what IDS thinks it has? Thanks, Edcel
EDCEL BARCENA said: > > I just wanted to clarify how does IDS determine the number of processors a > UNIX box have? Our new server(Sun Fire E6900) uses the UltraSPARC IV > processor, which is using the Chip Multithreading(CMT) technology. Through > CMT, 20 additional virtual processors are spawned apart from the 20 > physical processors that the server have. Running the mpstat will actually > show 40 cpus though the prtdiag only shows 20 cpus. My issue is I want to > bind not only the physical processor but the virtual processors as well. I > tried binding 26 processors but I'm getting "VPCLASS 'cpu' not enough > physical procs for affinity" message. Is there any way to tell IDS that > the server have more CPU than what IDS thinks it has? I think the short answer is "no". And in general, you'd not get any benefit from it, either. -- Bye now, Obnoxio "C'est pas parce qu'on n'a rien à dire qu'il faut fermer sa gueule" - Coluche "I'm trying to see things your way, but I can't get my head up my ass" - JCH "Ogni uomo mi guarda come se fossi una testa di cazzo" - Marco I went to the airport to check in and they asked what I did because I looked like a terrorist. I said I was a comedian. They said, "Say something funny then." I told them I had just graduated from flying school. -- Ahmed Ahmed
EDCEL BARCENA wrote: > Hello Everyone, > > I just wanted to clarify how does IDS determine the number of processors a UNIX box have? Our new server(Sun Fire E6900) uses the UltraSPARC IV processor, which is using the Chip Multithreading(CMT) technology. Through CMT, 20 additional virtual processors are spawned apart from the 20 physical processors that the server have. Running the mpstat will actually show 40 cpus though the prtdiag only shows 20 cpus. My issue is I want to bind not only the physical processor but the virtual processors as well. I tried binding 26 processors but I'm getting "VPCLASS 'cpu' not enough physical procs for affinity" message. Is there any way to tell IDS that the server have more CPU than what IDS thinks it has? It uses OS affinity libs AFAIK, which probably look at physical CPUs. Do you expect a performance advantage by using affinity? Have you tested that theory? In my experience affinity is more trouble that it's worth, not least issues with dynamically allocating CPU VPs. Try running without it and see what performance is like. Cheers, -- Mark. +----------------------------------------------------------+-----------+ | Mark D. Stock mailto:mdstock@MydasSolutions.com |//////// /| | http://MydasSolutions.com |///// / //| | +-----------------------------------+//// / ///| | |We value your comments, which have |/// / ////| | |been recorded and automatically |// / /////| | |emailed back to us for our records.|/ ////////| +----------------------+-----------------------------------+-----------+