memcg_stress cause cgroup_fj_function_memory and cgroup_fj_stress_memory* failed in controllers from ubuntu_ltp failed on B-aws-fips

[Po-Hsu Lin]

Issue found on specific instance i3en.24xlarge with 4.15.0-2028.28

It looks like this is a test case issue caused by cgroup_fj_function_memory test, which failed with:
 startup='Sat Oct 3 01:23:54 2020'
 cgroup_fj_function2_memory 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 cgroup_fj_function2_memory 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_function2_memory 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_function_memory stime=1601688234 dur=0 exit=exited stat=2 core=no cu=1 cs=1

Other cgroup_fj_stress_memory* tests failed with:
 startup='Sat Oct 3 01:27:01 2020'
 cgroup_fj_stress_memory_2_2_none 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_2_2_none 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_2_2_none 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_2_2_none 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_2_2_none stime=1601688421 dur=0 exit=exited stat=2 core=no cu=1 cs=1
 startup='Sat Oct 3 01:27:01 2020'
 cgroup_fj_stress_memory_3_3_none 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_3_3_none 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_3_3_none 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_3_3_none 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_3_3_none stime=1601688421 dur=0 exit=exited stat=2 core=no cu=1 cs=1
 startup='Sat Oct 3 01:27:01 2020'
 cgroup_fj_stress_memory_4_4_none 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_4_4_none 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_4_4_none 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_4_4_none 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_4_4_none stime=1601688421 dur=0 exit=exited stat=2 core=no cu=1 cs=1
 startup='Sat Oct 3 01:27:01 2020'
 cgroup_fj_stress_memory_2_9_none 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_2_9_none 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_2_9_none 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_2_9_none 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_2_9_none stime=1601688421 dur=0 exit=exited stat=2 core=no cu=1 cs=1
 startup='Sat Oct 3 01:27:01 2020'
 cgroup_fj_stress_memory_10_3_none 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_10_3_none 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_10_3_none 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_10_3_none 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_10_3_none stime=1601688421 dur=0 exit=exited stat=2 core=no cu=1 cs=1
 startup='Sat Oct 3 01:27:01 2020'
 cgroup_fj_stress_memory_1_200_none 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_1_200_none 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_1_200_none 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_1_200_none 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_1_200_none stime=1601688421 dur=0 exit=exited stat=2 core=no cu=1 cs=1
 startup='Sat Oct 3 01:27:01 2020'
 cgroup_fj_stress_memory_200_1_none 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_200_1_none 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_200_1_none 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_200_1_none 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_200_1_none stime=1601688421 dur=0 exit=exited stat=2 core=no cu=1 cs=1
 startup='Sat Oct 3 01:27:01 2020'
 cgroup_fj_stress_memory_2_2_one 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_2_2_one 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_2_2_one 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_2_2_one 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_2_2_one stime=1601688421 dur=0 exit=exited stat=2 core=no cu=1 cs=1
 startup='Sat Oct 3 01:27:01 2020'
 cgroup_fj_stress_memory_3_3_one 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_3_3_one 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_3_3_one 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_3_3_one 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_3_3_one stime=1601688421 dur=0 exit=exited stat=2 core=no cu=1 cs=0
 startup='Sat Oct 3 01:27:01 2020'
 cgroup_fj_stress_memory_4_4_one 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_4_4_one 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_4_4_one 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_4_4_one 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_4_4_one stime=1601688421 dur=0 exit=exited stat=2 core=no cu=1 cs=1
 startup='Sat Oct 3 01:27:02 2020'
 cgroup_fj_stress_memory_2_9_one 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_2_9_one 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_2_9_one 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_2_9_one 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_2_9_one stime=1601688422 dur=0 exit=exited stat=2 core=no cu=0 cs=1
 startup='Sat Oct 3 01:27:02 2020'
 cgroup_fj_stress_memory_10_3_one 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_10_3_one 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_10_3_one 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_10_3_one 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_10_3_one stime=1601688422 dur=0 exit=exited stat=2 core=no cu=1 cs=1
 startup='Sat Oct 3 01:27:02 2020'
 cgroup_fj_stress_memory_1_200_one 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_1_200_one 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_1_200_one 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_1_200_one 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_1_200_one stime=1601688422 dur=0 exit=exited stat=2 core=no cu=1 cs=1
 startup='Sat Oct 3 01:27:02 2020'
 cgroup_fj_stress_memory_200_1_one 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_200_1_one 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_200_1_one 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_200_1_one 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_200_1_one stime=1601688422 dur=0 exit=exited stat=2 core=no cu=1 cs=1
 startup='Sat Oct 3 01:27:02 2020'
 cgroup_fj_stress_memory_2_2_each 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_2_2_each 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_2_2_each 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_2_2_each 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_2_2_each stime=1601688422 dur=0 exit=exited stat=2 core=no cu=1 cs=0
 startup='Sat Oct 3 01:27:02 2020'
 cgroup_fj_stress_memory_3_3_each 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_3_3_each 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_3_3_each 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_3_3_each 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_3_3_each stime=1601688422 dur=0 exit=exited stat=2 core=no cu=1 cs=1
 startup='Sat Oct 3 01:27:02 2020'
 cgroup_fj_stress_memory_4_4_each 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_4_4_each 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_4_4_each 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_4_4_each 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_4_4_each stime=1601688422 dur=0 exit=exited stat=2 core=no cu=1 cs=1
 startup='Sat Oct 3 01:27:02 2020'
 cgroup_fj_stress_memory_2_9_each 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_2_9_each 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_2_9_each 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_2_9_each 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_2_9_each stime=1601688422 dur=0 exit=exited stat=2 core=no cu=1 cs=1
 startup='Sat Oct 3 01:27:02 2020'
 cgroup_fj_stress_memory_10_3_each 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_10_3_each 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_10_3_each 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_10_3_each 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_10_3_each stime=1601688422 dur=0 exit=exited stat=2 core=no cu=2 cs=0
 startup='Sat Oct 3 01:27:02 2020'
 cgroup_fj_stress_memory_1_200_each 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_1_200_each 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_1_200_each 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_1_200_each 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_1_200_each stime=1601688422 dur=0 exit=exited stat=2 core=no cu=1 cs=1
 startup='Sat Oct 3 01:27:02 2020'
 cgroup_fj_stress_memory_200_1_each 1 TINFO: Subsystem memory is mounted at /sys/fs/cgroup/memory
 /dev/memcg
 cgroup_fj_stress_memory_200_1_each 1 TINFO: Creating subgroups ...
 mkdir: cannot create directory ‘/sys/fs/cgroup/memory’: File exists
 mkdir: cannot create directory ‘/dev/memcg/ltp’: File exists
 cgroup_fj_stress_memory_200_1_each 1 TBROK: mkdir /sys/fs/cgroup/memory
 /dev/memcg/ltp failed
 cgroup_fj_stress_memory_200_1_each 1 TINFO: Removing all ltp subgroups...
 find: ‘/sys/fs/cgroup/memory\n/dev/memcg/ltp/’: No such file or directory
 tag=cgroup_fj_stress_memory_200_1_each stime=1601688422 dur=0 exit=exited stat=2 core=no cu=1 cs=1

[Po-Hsu Lin (cypressyew)]

Can be found on B-oracle. 4.15.0-1064.71 instance VM.DenseIO2.8 (passed on VM.Standard2.1)

[Po-Hsu Lin (cypressyew)]

It looks like it's actually the memcg_stress that will cause this File exists error before the others:

 startup='Fri Feb 26 09:16:58 2021'
 memcg_stress_test 1 TINFO: timeout per run is 0h 35m 0s
 memcg_stress_test 1 TINFO: Calculated available memory 120110 MB
 memcg_stress_test 1 TINFO: Testing 150 cgroups, using 799 MB, interval 5
 memcg_stress_test 1 TINFO: Starting cgroups
 memcg_stress_test 1 TINFO: Testing cgroups for 900s
 memcg_stress_test 1 TINFO: Killing groups
 tag=memcg_stress stime=1614331018 dur=902 exit=exited stat=2 core=no cu=20 cs=14
 startup='Fri Feb 26 09:32:06 2021'
 mkdir: cannot create directory ‘/tmp/ltp-b8iNdDzNY4/mnt/1’: File exists
 memcg_control 0 TINFO : Test #1: Checking if the memory usage limit imposed by the topmost group is enforced
 sh: echo: I/O error
 /opt/ltp/testcases/bin/memcg_control_test.sh: 86: /opt/ltp/testcases/bin/memcg_control_test.sh: cannot create /tmp/ltp-b8iNdDzNY4/mnt/1/memory.memsw.limit_in_bytes: Permission denied
 memcg_control 1 TFAIL : ltpapicmd.c:188: Test #1: failed
 rmdir: failed to remove 'sub': Device or resource busy
 rmdir: failed to remove '/tmp/ltp-b8iNdDzNY4/mnt/1': Device or resource busy
 memcg_control 1 TPASS : memcg_control: passed
 tag=memcg_control stime=1614331926 dur=6 exit=exited stat=0 core=no cu=2 cs=1

[Kelsey Steele (kelsey-steele)]

Also found on Focal/linux 5.8.0-49.55~20.04.1 lowlatency on host onibi. Not seeing the failures on host spitfire.

[Guilherme G. Piccoli (gpiccoli)]

Found on Focal/linux-kvm, cycle sru-20210315

[Guilherme G. Piccoli (gpiccoli)]

Found this on groovy:linux-kvm, cycle sru-20210315.

[Guilherme G. Piccoli (gpiccoli)]

Found this on focal:linux-kvm, cycle sru-20210412.

[Guilherme G. Piccoli (gpiccoli)]

Found this on bionic:linux-kvm, cycle sru-20210412.

[Guilherme G. Piccoli (gpiccoli)]

Found this on focal:linux-kvm, cycle sru-20210510.

[Guilherme G. Piccoli (gpiccoli)]

Observed in B/KVM, cycle sru-20210510.

[Guilherme G. Piccoli (gpiccoli)]

Observed in H/KVM, cycle sru-20210510.

[Guilherme G. Piccoli (gpiccoli)]

Issue observed in G/KVM, cycle sru-20210531 .

[Kleber Sacilotto de Souza (kleber-souza)]

Also found with focal/linux-hwe-5.11 5.11.0-20.21~20.04.1.

[Guilherme G. Piccoli (gpiccoli)]

Observed in G/Oracle kernel, cycle sru-20210621 .

[Guilherme G. Piccoli (gpiccoli)]

Observed in G/aws kernel, cycle sru-20210621 .

[Guilherme G. Piccoli (gpiccoli)]

Observed in B/aws-5.4 kernel, cycle sru-20210621 .

[Guilherme G. Piccoli (gpiccoli)]

Observed this on B/oracle-5.4, cycle sru-20210621 .

[Guilherme G. Piccoli (gpiccoli)]

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

[Guilherme G. Piccoli (gpiccoli)]

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

[Guilherme G. Piccoli (gpiccoli)]

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

[Krzysztof Kozlowski (krzk)]

Found on B/azure-4.15 only on Standard_D48_v3 instances. Reproducible via Jenkins jobs but unable to reproduce directly by running ltp. Might be similar to lp:1836694

[Krzysztof Kozlowski (krzk)]

Sent patch upstream: https://lists.linux.it/pipermail/ltp/2021-July/023987.html

[Krzysztof Kozlowski (krzk)]

Steps to reproduce:
1. install LTP (e.g. locally)
2. sudo ./runltp -s memcg_stress
3. sudo ./runltp -s memcg_control
4. sudo ./runltp -s cgroup_fj_function

[Krzysztof Kozlowski (krzk)]

Committed upstream.