RFR: 8326726: Problem list Exhaustiveness.java due to 8326616 [v2]

[SendaoYan]

> The testcase tools/javac/patterns/Exhaustiveness.java intermittently timeout after [8325215](https://bugs.openjdk.org/browse/JDK-8325215).
> 
> I change the timeout value from 120(default value) to 300 locally, and set timeoutFactor to 20, then run this testcase 1000 times, use the concurrecy 16(the half of the nproc).
> The test result show that, 90% of the test run finish in 20 seconds, but 15 times test exaust more than 5000 seconds.
> So, maybe be we should change the timeout value from 120(default value) to 6000.
> 
> Mine test command:
> 
> export test=test/langtools/tools/javac/patterns/Exhaustiveness.java
> nproc=`nproc` ; dir="tmp-jtreg-"`basename $test .java` ; rm -rf $dir ; mkdir -p $dir ; time seq 1000 | xargs -i -n 1 -P `expr $nproc / 2` bash -c "jtreg -ea -esa -timeoutFactor:20 -v:fail,error,time,nopass -nr -w $dir/index-{} $test &> $dir/{}.log ; grep 'Test results: passed: 1' -L $dir/{}.log"
> 
> 
> The command statistic the time elapsed testcase run:
> 
> for i in `seq 1000` ; do grep "elapsed time" index-$i/tools/javac/patterns/Exhaustiveness.jtr | tail -n 1 ; done | awk -F ':' '{print $NF}' | sort -n > time-statistics.log
> 
> 
> [time-statistics.log](https://github.com/openjdk/jdk/files/14396886/time-statistics.log)
> 
> 
> The CPU and memory information:
> 
> [root at iZbp1fauxu0pkmhplfguv6Z ~]# lscpu 
> Architecture:        x86_64
> CPU op-mode(s):      32-bit, 64-bit
> Byte Order:          Little Endian
> CPU(s):              32
> On-line CPU(s) list: 0-31
> Thread(s) per core:  2
> Core(s) per socket:  16
> Socket(s):           1
> NUMA node(s):        1
> Vendor ID:           GenuineIntel
> BIOS Vendor ID:      Alibaba Cloud
> CPU family:          6
> Model:               106
> Model name:          Intel(R) Xeon(R) Platinum 8369B CPU @ 2.70GHz
> BIOS Model name:     pc-i440fx-2.1
> Stepping:            6
> CPU MHz:             3500.041
> BogoMIPS:            5399.99
> Hypervisor vendor:   KVM
> Virtualization type: full
> L1d cache:           48K
> L1i cache:           32K
> L2 cache:            1280K
> L3 cache:            49152K
> NUMA node0 CPU(s):   0-31
> Flags:               fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc cpuid aperfmperf tsc_known_freq pni pclmulqdq monitor ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch cpuid_fault invpcid_single ibrs_enhanced fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid avx512f avx512dq rds...

SendaoYan has updated the pull request incrementally with two additional commits since the last revision:

 - 8326726: Problem list Exhaustiveness.java due to 8326616
   
   Signed-off-by: sendaoYan <yansendao.ysd at alibaba-inc.com>
 - 8326726: Problem list Exhaustiveness.java due to 8326616
   
   Signed-off-by: sendaoYan <yansendao.ysd at alibaba-inc.com>

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/17998/files
  - new: https://git.openjdk.org/jdk/pull/17998/files/8d4d2754..f4caab17

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17998&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17998&range=00-01

  Stats: 2 lines in 2 files changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/17998.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17998/head:pull/17998

PR: https://git.openjdk.org/jdk/pull/17998