getrandom02 from ubuntu_ltp_syscalls failed with timeout multiplier = 3 on D-KVM

[Po-Hsu Lin]

Even with the timeout multiplier set to 3, the test is still failing:

 Waiting for pid 1892 for 21600 seconds
 Checking virt-what to see if we need to set LTP_TIMEOUT_MUL...
 Running in VM, set timeout multiplier LTP_TIMEOUT_MUL=3 (lp:1797327)
 == Test Suite Summary ==
 7 test cases failed
 0 test cases blacklisted
 Failed test cases : acct01 getrandom02 msgstress03 quotactl01 quotactl02 quotactl03 sync_file_range02

startup='Thu May 30 21:36:06 2019'
tst_test.c:1096: INFO: Timeout per run is 0h 15m 00s
getrandom02.c:72: PASS: getrandom returned 256
Test timeouted, sending SIGKILL!
tst_test.c:1136: INFO: If you are running on slow machine, try exporting LTP_TIMEOUT_MUL > 1
tst_test.c:1137: BROK: Test killed! (timeout?)

Summary:
passed 1
failed 0
skipped 0
warnings 0
tag=getrandom02 stime=1559252166 dur=900 exit=exited stat=2 core=no cu=0 cs=0

[Colin Ian King (colin-king)]

I suspect this is due to lack of entropy on the machine.

[Po-Hsu Lin (cypressyew)]

Will try to increase the timeout multiplier.
Or install the haveged to see if it helps.

[Colin Ian King (colin-king)]

Maybe exercising the disc(s) may help, this generates interrupts that get used to add entropy to the entropy pool.

[Colin Ian King (colin-king)]

..or network too.

[Po-Hsu Lin (cypressyew)]

Issue found on Oracle B-4.15 instance: VM.Standard2.24

[Po-Hsu Lin (cypressyew)]

It looks like haveged helps a lot:

Before installing haveged:
ubuntu@groucho:~$ cat /proc/sys/kernel/random/entropy_avail
79
After:
ubuntu@groucho:~$ cat /proc/sys/kernel/random/entropy_avail
2424

The getrandom tests will finish in the blink of an eye.

[Po-Hsu Lin (cypressyew)]

https://kernel.ubuntu.com/git/ubuntu/autotest-client-tests.git/commit/?id=389617c59d93082c9cb937015879a8adece5bcc6