clock_nanosleep02 from ubuntu_ltp_syscalls failed on some bare metal nodes with X-AWS-4.4 / X-AWS-4.15 / B-AWS-4.15 / B-oem-4.15

[Po-Hsu Lin]

Issue found on i3.metal and c5.metal amd64 instances with aws 4.15.0-1066.70~16.04.1, passed on r5.metal and other instances

Test failed with:
 tst_timer_test.c:310: FAIL: clock_nanosleep() slept for too long

 startup='Sun Apr 12 19:33:14 2020'
 tst_test.c:1241: INFO: Timeout per run is 0h 05m 00s
 tst_timer_test.c:348: INFO: CLOCK_MONOTONIC resolution 1ns
 tst_timer_test.c:360: INFO: prctl(PR_GET_TIMERSLACK) = 50us
 tst_timer_test.c:264: INFO: clock_nanosleep() sleeping for 1000us 500 iterations, threshold 450.01us
 tst_timer_test.c:307: INFO: min 1063us, max 1084us, median 1067us, trunc mean 1066.81us (discarded 25)
 tst_timer_test.c:322: PASS: Measured times are within thresholds
 tst_timer_test.c:264: INFO: clock_nanosleep() sleeping for 2000us 500 iterations, threshold 450.01us
 tst_timer_test.c:307: INFO: min 2071us, max 2078us, median 2077us, trunc mean 2076.76us (discarded 25)
 tst_timer_test.c:322: PASS: Measured times are within thresholds
 tst_timer_test.c:264: INFO: clock_nanosleep() sleeping for 5000us 300 iterations, threshold 450.04us
 tst_timer_test.c:307: INFO: min 5066us, max 5108us, median 5106us, trunc mean 5103.24us (discarded 15)
 tst_timer_test.c:322: PASS: Measured times are within thresholds
 tst_timer_test.c:264: INFO: clock_nanosleep() sleeping for 10000us 100 iterations, threshold 450.33us
 tst_timer_test.c:307: INFO: min 10132us, max 10147us, median 10135us, trunc mean 10138.91us (discarded 5)
 tst_timer_test.c:322: PASS: Measured times are within thresholds
 tst_timer_test.c:264: INFO: clock_nanosleep() sleeping for 25000us 50 iterations, threshold 451.29us
 tst_timer_test.c:307: INFO: min 25221us, max 25258us, median 25233us, trunc mean 25239.48us (discarded 2)
 tst_timer_test.c:322: PASS: Measured times are within thresholds
 tst_timer_test.c:264: INFO: clock_nanosleep() sleeping for 100000us 10 iterations, threshold 537.00us
 tst_timer_test.c:307: INFO: min 100215us, max 100773us, median 100684us, trunc mean 100638.44us (discarded 1)
 tst_timer_test.c:310: FAIL: clock_nanosleep() slept for too long

 Time: us | Frequency
 --------------------------------------------------------------------------------
 100215 | ***********-
 100245 |
 100275 |
 100305 |
 100335 |
 100365 |
 100395 |
 100425 |
 100455 |
 100485 |
 100515 |
 100545 |
 100575 |
 100605 |
 100635 |
 100665 | ********************************************************************
 100695 | ***********-
 100725 | ***********-
 100755 | ***********-
 --------------------------------------------------------------------------------
 30us | 1 sample = 11.33333 '*', 22.66667 '+', 45.33333 '-', non-zero '.'

 tst_timer_test.c:264: INFO: clock_nanosleep() sleeping for 1000000us 2 iterations, threshold 4400.00us
 tst_timer_test.c:307: INFO: min 1003376us, max 1005030us, median 1003376us, trunc mean 1003376.00us (discarded 1)
 tst_timer_test.c:322: PASS: Measured times are within thresholds

 Summary:
 passed 6
 failed 1
 skipped 0
 warnings 0

[Po-Hsu Lin (cypressyew)]

This issue can be found on Bionic 4.15 AWS as well.

I tried to reproduce this manually, however with instance c5.large (which is failing with this case on B-AWS-4.15), I can't reproduce this with 4.15.0-1065-aws / 4.15.0-1066-aws by just running this clock_nanosleep02 test case.

[Po-Hsu Lin (cypressyew)]

Can be found on Xenial AWS 4.4.0-1108 (i3.metal, c5.metal, pass on r5.metal)

[Po-Hsu Lin (cypressyew)]

Found on B-oem 4.15.0-1094.104

[Po-Hsu Lin (cypressyew)]

Didn't see this on X-AWS-4.15 this cycle.

[Po-Hsu Lin (cypressyew)]

Still visible in Xenial 4.4.0-1118.132 AWS c5.metal

[Po-Hsu Lin (cypressyew)]

Found on 4.15.0-1059.65 - oracle
BM.Standard2.52 only

[Po-Hsu Lin (cypressyew)]

Spotted on B-4.15.0-1049.56 fips

[Po-Hsu Lin (cypressyew)]

BTW on B-4.15 it's because the kernel config does not match its requirement.

[Po-Hsu Lin (cypressyew)]

Can see this on F-aws 5.4 but only on arm64 instance a1.2xlarge

[Francis Ginther (fginther)]

Seen with linux-aws 4.15.0-1094.101~16.04.1.

[Kelsey Steele (kelsey-steele)]

Found on bionic/fips 4.15.0-1053.61

[Guilherme G. Piccoli (gpiccoli)]

Observed in B/oracle (kernel 4.15), cycle sru-20210621.