RFR: CODETOOLS-7902919: jcstress: Sysfs topology parser fails due to oddly intersecting core IDs

[Christoph Göttschkes]

On Tue, 4 May 2021 14:07:38 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> The sysfs parser is still incomplete: it tries to generate synthetic core IDs when they appear to belong to different packages. In doing so, it multiplies by the number of packages -- which is incorrect, and we should multiply at least by the max number of cores per package. We might as well multiply by the number of CPUs to be on the safe side.

Thanks a lot for the fast fix. Sadly, the `test_Current` of `LinuxProcfsTopologyTest` still fails on that machine:


test_Current(org.openjdk.jcstress.os.topology.LinuxProcfsTopologyTest)  Time elapsed: 0.03 sec  <<< ERROR!
org.openjdk.jcstress.os.topology.TopologyParseException: Core belongs to different packages: P1, C0, T1, 0
	at org.openjdk.jcstress.os.topology.AbstractTopology.add(AbstractTopology.java:78)
	at org.openjdk.jcstress.os.topology.LinuxProcfsTopology.<init>(LinuxProcfsTopology.java:61)
	at org.openjdk.jcstress.os.topology.LinuxProcfsTopology.<init>(LinuxProcfsTopology.java:41)
	at org.openjdk.jcstress.os.topology.LinuxProcfsTopologyTest.test_Current(LinuxProcfsTopologyTest.java:22)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63)
	at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329)
	at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:413)
	at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:264)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:153)
	at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:124)
	at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:200)
	at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:153)
	at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:103)


`lscpu` reports:


Architecture:                    x86_64
CPU op-mode(s):                  32-bit, 64-bit
Byte Order:                      Little Endian
Address sizes:                   38 bits physical, 48 bits virtual
CPU(s):                          8
On-line CPU(s) list:             0-7
Thread(s) per core:              1
Core(s) per socket:              4
Socket(s):                       2
NUMA node(s):                    1
Vendor ID:                       GenuineIntel
CPU family:                      6
Model:                           23
Model name:                      Intel(R) Xeon(R) CPU           E5440  @ 2.83GHz
Stepping:                        6
CPU MHz:                         1994.891
CPU max MHz:                     2833.0000
CPU min MHz:                     2000.0000
BogoMIPS:                        5652.19
Virtualization:                  VT-x
L1d cache:                       256 KiB
L1i cache:                       256 KiB
L2 cache:                        24 MiB
NUMA node0 CPU(s):               0-7
Vulnerability Itlb multihit:     KVM: Mitigation: Split huge pages
Vulnerability L1tf:              Mitigation; PTE Inversion; VMX EPT disabled
Vulnerability Mds:               Vulnerable: Clear CPU buffers attempted, no microcode; SMT disabled
Vulnerability Meltdown:          Mitigation; PTI
Vulnerability Spec store bypass: Vulnerable
Vulnerability Spectre v1:        Mitigation; usercopy/swapgs barriers and __user pointer sanitization
Vulnerability Spectre v2:        Mitigation; Full generic retpoline, STIBP disabled, RSB filling
Vulnerability Srbds:             Not affected
Vulnerability Tsx async abort:   Not affected
Flags:                           fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl cpuid aperfmperf pni dtes6
                                 4 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 lahf_lm pti tpr_shadow vnmi flexpriority dtherm


This looks like your test is correct.

-------------

PR: https://git.openjdk.java.net/jcstress/pull/47