Processor Affinity on a 2 CPU HP9000

We are running HP-UX 10.20 on an HP9000 with version 7.22 of Informix Online Dynamic Server. We currently are running the server with processor affinity switched off. Using the Unix top command I can see that the oninit CPU VP process is constantly switching between CPU 0 & CPU1, this must incur overheads when the process switch happens. Is it a good idea therefore to enable processor affinity? I would have thought it would be better to assign the second processor although again I am not sure. Below are our current $ONCONFIG file entries: MULTIPROCESSOR 1 # 0 for single-processor, 1 formulti-processor NUMCPUVPS 1 # Number of user (cpu) vps SINGLE_CPU_VP 1 # If non-zero, limit number of cpu vps toone NOAGE 1 # Process aging AFF_SPROC 0 # Affinity start processor AFF_NPROCS 0 # Affinity number of processors Could anybody please help. Thanks in advance Paul Wheeler Leaderflush+Shapland Limited Nottingham England.

Is processor affinity supported in v7.22 on HP-UX 10.20? It is in v7.24, but wasn't in (I think) v7.13. Running v7.24 on HP-UX 10.20 on an HP9000 with 2 processors, and noticing long ready queues with onstat -g, I got good performance improvements by adding a second cpu vp (in defiance of TFM!). Neil Truby Londis Stores Hampton Hill, UK Paul Wheeler wrote in message <943353689.1230.0.nnrp-02.d4e45b75@news.demon.co.uk>... >We are running HP-UX 10.20 on an HP9000 with version 7.22 of Informix Online >Dynamic Server. > >We currently are running the server with processor affinity switched off. >Using the Unix top command I can see that the oninit CPU VP process is >constantly switching between CPU 0 & CPU1, this must incur overheads when >the process switch happens. > >Is it a good idea therefore to enable processor affinity? I would have >thought it would be better to assign the second processor although again I >am not sure. > >Below are our current $ONCONFIG file entries: > >MULTIPROCESSOR 1 # 0 for single-processor, 1 for>multi-processor >NUMCPUVPS 1 # Number of user (cpu) vps >SINGLE_CPU_VP 1 # If non-zero, limit number of cpu vps to>one > >NOAGE 1 # Process aging >AFF_SPROC 0 # Affinity start processor >AFF_NPROCS 0 # Affinity number of processors> >Could anybody please help. > > >Thanks in advance > > >Paul Wheeler >Leaderflush+Shapland Limited >Nottingham >England. > >

In article <943353689.1230.0.nnrp-02.d4e45b75@news.demon.co.uk>, "Paul Wheeler" <paul.wheeler@leaderflushshapland.co.uk> wrote: > We are running HP-UX 10.20 on an HP9000 with version 7.22 of Informix Online > Dynamic Server. > > We currently are running the server with processor affinity switched off. > Using the Unix top command I can see that the oninit CPU VP process is > constantly switching between CPU 0 & CPU1, this must incur overheads when > the process switch happens. > > Is it a good idea therefore to enable processor affinity? I would have > thought it would be better to assign the second processor although again I > am not sure. With 2CPUs and 1 CPU VP I'd say there is not much to gain from affinity. Testing is the only way to be sure. I'd suggest affining the VP to CPU #1 rather than #0 as #0 tends to do more system call work. Art S. Kagel Art S. Kagel Sent via Deja.com http://www.deja.com/ Before you buy.