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Old October 12th, 2007, 15:47
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Re: [INSTRUCTIONS] Testing VPD Query Performance

Kristof,

Thanks for the setting. Doing some research, this appears to be related to an issue specific to the HP-UX platform, but it would be interesting to see if hit helps other platforms also. I know that Ian is running on AIX and the bulk of our clients are running on Linux.

Here's some details on the issue: Oracle Doc ID# 433631.1
Mutex Latch Spin Causes High Cpu on Non-CAS Platforms (HP-UX PA-RISC )
Quote:
CPU usage greatly increased on 10.2.0.2 compared to 9.2.0.6 while performing testing..
Problem only occurs on HP-UX PA-RISC.
Disabling mutexes reduced CPU usage by 10%-15%

To avoid using Mutex latches, you can set _kks_use_mutex_pin=false

10.2.0.2 defaults the use of mutexes for certain shared cursor operations,
instead of library cache latches and library cache pin latches and library
cache pins. Mutexes use the CAS (compare and swap) operation.
This is going to be resolved shortly in 10.2.0.4 - as part of bug # 5399325.

Thanks,
Chris
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