IDS Forum

RE: CPUVP overloaded but physical CPU only 50% used

Posted By: Jay Aymond
Date: Wednesday, 9 July 2003, at 4:29 p.m.

In Response To: CPUVP overloaded but physical CPU only 50% used (geoff.poole@verizon.com)

Since you can add and remove virtual CPU's with the onmode command, you
could try it and see if the physical CPU goes up and the number of ready
threads goes down.

We have a Sun V880 with 4 900 MHz CPU's and run with the number of
virtual CPU's equal to the number of physical CPU's.



-----Original Message-----
From: geoff.poole.... [mailto:geoff.poole@verizon.com]
Sent: Wednesday, July 09, 2003 2:41 PM
To: ids@iiug.org
Subject: CPUVP overloaded but physical CPU only 50% used [1524]


Has anyone set NUMCPUVP to be more than the number of physical CPUs ?
and has anyone seen similar problems.

We have a problem that our informix instance gets overloaded (30+ active
queries for minutes) with user complaining of timed out jobs, but our
total CPU's utilization (sar) stays below 50% and I note that we have
lots of ready threads. I've set NUMCPUS to 7 which is text book -1 the
number of physical CPUs (8).

Could it be that in the new super-fast CPU clock speeds that the
engine's internal architecture needs to be rethought, perhaps threads
are yielding too quickly and there is a problem with the mechanism of
thread context switching ?

Versions: 9.30.FC2R1 AIX 5.1
System Model: IBM,7040-681
Memory Size: 32768 MB
Number Of Processors: 8
Processor Clock Speed: 1300 MHz
CPU Type: 64-bit

Geoff Poole
Verizon Florida

Messages In This Thread

• CPUVP overloaded but physical CPU only 50% used
  geoff.poole@verizon.com -- Wednesday, 9 July 2003, at 3:40 p.m.
  • RE: CPUVP overloaded but physical CPU only 50% used
    Jay Aymond -- Wednesday, 9 July 2003, at 4:29 p.m.
  • Re: CPUVP overloaded but physical CPU only 50% used
    Madison Pruet -- Wednesday, 9 July 2003, at 5:26 p.m.
    • Re: CPUVP overloaded but physical CPU only 50% used
      Mark Scranton -- Wednesday, 9 July 2003, at 8:06 p.m.
  • Re: CPUVP overloaded but physical CPU only 50% used
    Michael Mueller -- Thursday, 10 July 2003, at 7:40 a.m.
  • CPUVP overloaded but physical CPU only 50% used
    Gregory S. Williamson -- Thursday, 10 July 2003, at 5:41 p.m.

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