AWR Reporting Incorrect DB Time/CPU Time on IBM AIX 7.1

    AWR shows incorrect  DB Time/CPU Time  IBM AIX 64 bit 7.1 TL3 SP5

                                 thread_cputime() returns incorrect values

Current Environment:

Oracle Database 12.1.0.2 on AIX 64 7.1 bit TL3 SP5

Error Description :

AWR report shows huge number of DB time.

Error Identification:
Refer below AWR report where we can see high DB Time/CPU Time which is not acceptable.  It is BUG on AIX 64 bit. I checked with OS admin to find CPU utilization on AIX server but it was idle during the issue time. Also, I did not find any performance bottlenecks in AWR report, except this.

You can see the below DB Time 138,467,374,105.76(mins) in AWR report which is too high.

Problem Resolution:
IBM AIX 7.1 on POWER Systems (64-Bit) Minimum Operating System Requirements:

AIX 7.1 Technology Level 1 Service Pack 3 ("7100-01-03-1207") or later, 64-bit kernel

Note: You can install on AIX 7.1 Technology Level 1 but Oracle recommends that you install on AIX 7.1 Technology Level 3 Service Pack 3 (7100-03-03-1415) or later. The latter includes all the APARs and operating system fixes.

Below is the affected APARs on AIX 7.1:

• IV34869 - thread_cputime() returns incorrect values

The following, or later, patch is also required if you use Oracle Automatic Storage Management Cluster File System (Oracle ACFS). At the time of this release, the patch is unavailable for TL7 so the APAR number refers to the base APAR:

Note:

• If you are using a later TL level than the minimum level listed for this release, then contact IBM to determine if the required APARs listed in this section are included in the TL level that you have on your system. If they are included, then you do not have to install them. If they are not included, then you must install the equivalent APAR for the appropriate TL level.
• AIX APAR numbers are tied to AIX versions and technology levels. Download and install the APAR that matches your AIX versions and Technology Levels from the IBM fix central website at the following URL:
  http://www.ibm.com

In our client environment, Oracle 12.1.0.2 database was running on AIX 64 7.1 bit TL3 SP5.

We have upgraded AIX 7.1 TL3 SP5 to AIX 7.1 TL3 SP8 and AWR report showed correct DB Time/CPU Time.

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