JDK-8030957 - AIX: Implement OperatingSystemMXBean.getSystemCpuLoad() and .getProcessCpuLoad() on AIX

[suchismith1993]

JBS Issue : JDK-8030957

These two methods should be implemented in src/aix/native/sun/management/AixOperatingSystem.c (which has to be created).

getProcessCpuLoad() can be probably implemented in the same way like on Solaris be reading /proc/self/psinfo

For getSystemCpuLoad() we'll probalby have to use 'perfstat_cpu_total()' from libperf (see http://publib.boulder.ibm.com/infocenter/pseries/v5r3/topic/com.ibm.aix.prftools/doc/prftools/prftools07.htm#wq407)

Once this issue has been resolved you should not forget to remove the two excludes from jdk/test/ProblemList.txt:

com/sun/management/OperatingSystemMXBean/GetProcessCpuLoad.java aix-all
com/sun/management/OperatingSystemMXBean/GetSystemCpuLoad.java aix-all

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Error

 ⚠️ 8030957 is used in problem lists: [test/jdk/ProblemList.txt]

Issue

• JDK-8030957: AIX: Implement OperatingSystemMXBean.getSystemCpuLoad() and .getProcessCpuLoad() on AIX (Enhancement - P4)

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[MBaesken]

I noticed that we check for retval < 0 in os_perf_aix.cpp, should we align this in some way ?

[MBaesken]

Are you sure the perfstat functionality is always available ?
In HS we do dynamic resolution (see e.g. os_perf_aix.cpp), but maybe that was needed long time ago and is not really needed any more? But please check this .

[suchismith1993]

Are you sure the perfstat functionality is always available ? In HS we do dynamic resolution (see e.g. os_perf_aix.cpp), but maybe that was needed long time ago and is not really needed any more? But please check this .

I tried with a standalone program and did not face any issues.

[suchismith1993]

@MBaesken would it be possible for you to try this patch once to see if the load values are realistic / accurate ?
Else if you can provide some use case that I can try.

[MBaesken]

Are you sure the perfstat functionality is always available ? In HS we do dynamic resolution (see e.g. os_perf_aix.cpp), but maybe that was needed long time ago and is not really needed any more? But please check this .

I tried with a standalone program and did not face any issues.

I was more thinking about different AIX machines setups/OS levels/installations. Is the perfstat functionality always there 'these days' ?

[MBaesken]

would it be possible for you to try this patch once to see if the load values are realistic / accurate ?

Not 100% sure how, should we compare with values provided by other tools (system tools etc.) ?

[suchismith1993]

Are you sure the perfstat functionality is always available ? In HS we do dynamic resolution (see e.g. os_perf_aix.cpp), but maybe that was needed long time ago and is not really needed any more? But please check this .

I tried with a standalone program and did not face any issues.

I was more thinking about different AIX machines setups/OS levels/installations. Is the perfstat functionality always there 'these days' ?

Hi @MBaesken It seems perfstat is available since AIX 5. I see there is dynamic loading done in libperfstat.cpp. How to confirm if that is necessary ? I did not face issues in this program and also standalone C++ program on AIX 7.2

[MBaesken]

How to confirm if that is necessary ? I did not face issues in this program and also standalone C++ program on AIX 7.2

We did this not only because of (un)availability of libperfstat , but also to address different versions (with different functionality) of libperfstat at runtime.

[MBaesken]

If we only address minimum AIX 7.2 we can probably simplify this approach or even go away from the current dynamic loading approach.
See also https://bugs.openjdk.org/browse/JDK-8222719 where I did already some cleanup (but kept the AIX 7.1 vs. 7.2 ) .

[MBaesken]

There is still an fflush(stdout); in UnixOperatingSystem.c - guess this is not needed any more?