On some larger Aarch64 Linux machines we see test failures with default test job configs. Failures usually look like this:

STDERR:
 stdout: [[0.012s][warning][os,thread] Failed to start thread - pthread_create failed (EAGAIN) for attributes: stacksize: 2048k, guardsize: 64k, detached.
#
# There is insufficient memory for the Java Runtime Environment to continue.
# Cannot create worker GC thread. Out of system resources.
# An error report file with more information is saved as:
# /home/openjdk/jdk11u/build/linux-aarch64-normal-server-release/test-support/jtreg_test_hotspot_jtreg_tier1/scratch/14/hs_err_pid83190.log

We observe such failures when the number of available processor cores is large (e.g. 96), yet the 'ulimit -u' setting for the user running tests is rather low:

$ ulimit -u
4096
$ id
uid=1001(openjdk) gid=1001(openjdk) groups=1001(openjdk) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023