mm:min_free_kbytes in ubuntu_ltp failed with ENOMEM on system with small ram

[Po-Hsu Lin]

Issue found on B-gcp-fips 4.15.0-2031.34 with instance g1-small (1.7 Gib ram, according to [1])

INFO: Test start time: Fri Apr 15 09:43:05 UTC 2022
COMMAND: /opt/ltp/bin/ltp-pan -q -e -S -a 10760 -n 10760 -f /tmp/ltp-8tfChAaI3S/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:1447: TINFO: Timeout per run is disabled
mem.c:631: TINFO: set overcommit_memory to 2
mem.c:631: TINFO: set min_free_kbytes to 45056
min_free_kbytes.c:115: TBROK: fork: ENOMEM (12)
mem.c:631: TINFO: set min_free_kbytes to 45056
mem.c:631: TINFO: set overcommit_memory to 0
tst_test.c:1500: TINFO: Killed the leftover descendant processes

Summary:
passed 0
failed 0
broken 1
skipped 0
warnings 0
INFO: ltp-pan reported some tests FAIL
LTP Version: 20220121
INFO: Test end time: Fri Apr 15 09:43:05 UTC 2022

[1] https://gcpinstances.doit-intl.com/?selected=g1-small

[Portia Stephens (portias)]

Also seen in focal xilinx-linux-zyqnmp-5.4.0-1018.21 , the system has 1.4Gi RAM free.

              total used free shared buff/cache available
Mem: 3.8Gi 460Mi 1.4Gi 3.0Mi 2.0Gi 3.2Gi
Swap: 0B 0B 0B