The system environment and performance tuning

Performance Factor Description Documentation
Activity settings:

Activity Delay
Activity Duration
Activity Launch

The settings for the Activity will affect the performance results. Usually you will want to ensure the two Activities you are comparing have the same settings. Creating a Hotspot Detection Activity
System host information:

Host Name
Operating System
CPU Type
CPU Count
CPU Frequency

The system where the application was run can have a major impact on the performance. Hardware and operating system differences can mean different behaviour, but even on similar systems that are configured differently can affect performance. Understanding performance tuning
Execution environment:

CPU Idle (%)
CPU I/O Wait
CPU Stolen

Other applications running on the system or even other systems in the case of virtual machines can affect application performance. Changes in idle CPU time or I/O wait time can indicate the two runs may have been affected by other applications in the system. "Stolen" time indicates the hypervisor may have taken cycles away from your virtual machine to give to another virtual machine. Understanding performance tuning
Environment variable:

LDR_CNTRL

You can use the LDR_CNTRL environment variable to configure an application to use large pages for the application's data and heap segments. Setting an environment variable to request large pages
Environment variables:

MALLOCALIGN
MALLOCTYPE
MALLOCOPTIONS
MALLOCDEBUG
MALLOCBUCKETS
MALLOCMULTIHEAP

These variables allow you to specify the memory allocation policy. System Memory Allocation Using the malloc Subsystem
Environment variables:

AIXTHREAD_AFFINITY
AIXTHREAD_COND_DEBUG
AIXTHREAD_ENRUSG
AIXTHREAD_MNRATIO
AIXTHREAD_MUTEX_DEBUG
AIXTHREAD_MUTEX_FAST
AIXTHREAD_PREALLOC
AIXTHREAD_RWLOCK_DEBUG
AIXTHREAD_SCOPE
AIXTHREAD_SUSPENDIBLE
SPINLOOPTIME
YIELDLOOPTIME

Within the libpthreads.a framework, a series of tuning knobs have been provided that might impact the performance of the application. Thread environment variables
Environment variable:

MEMORY_AFFINITY

Allows you to configure the placement of user memory. Memory placement with the MEMORY_AFFINITY environment variable

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