msgstress01 from ubuntu_ltp_syscalls failed with WARNING (TWARN: Out of runtime during forking...)

[Po-Hsu Lin]

This issue pops up with 8f21ebba42 LTP 20240524 update.
This was spotted on openstack ARM64 instances with F/N, I assume we will see this on other releases with more tests.

The test is not really failing, it's the WARNING that emitted by the test that cause this problem.

INFO: Test start time: Wed Jun 19 09:34:59 UTC 2024
COMMAND: /opt/ltp/bin/ltp-pan -q -e -S -a 137951 -n 137951 -f /tmp/ltp-yQanT2tSBp/alltests -l /dev/null -C /dev/null -T /dev/null
LOG File: /dev/null
FAILED COMMAND File: /dev/null
TCONF COMMAND File: /dev/null
Running tests.......
tst_test.c:1733: TINFO: LTP version: 20240524
tst_test.c:1617: TINFO: Timeout per run is 0h 03m 30s
tst_pid.c:84: TINFO: Cannot read session user limits from '/sys/fs/cgroup/user.slice/user-1000.slice/pids.max'
tst_pid.c:94: TINFO: Found limit of processes 10027 (from /sys/fs/cgroup/pids/user.slice/user-1000.slice/pids.max)
msgstress01.c:271: TINFO: Available messages slots: 4675
msgstress01.c:217: TWARN: Out of runtime during forking...
msgstress01.c:246: TPASS: Test passed. All messages have been received

Summary:
passed 1
failed 0
broken 0
skipped 0
warnings 1
INFO: ltp-pan reported some tests FAIL
LTP Version: 20240524
INFO: Test end time: Wed Jun 19 09:38:00 UTC 2024

Caused by https://github.com/linux-test-project/ltp/commit/dac76a85fc0222ba20e1d269b00eb1fe78d530f1

[Portia Stephens (portias)]

I see this on a non ARM64 system. bionic/linux-gcp-4.15: 4.15.0-1163.180

[Po-Hsu Lin (cypressyew)]

Found on Azure AMD64 Standard_A2_v2 5.4.0-1133.140 as well.