ubuntu_ramfs_stress OOM on 4.15 KVM kernel

[Po-Hsu Lin]

This test will fail with the 4.15 kvm kernel in -release.
Therefore this might not be a kernel regression but a tool issue.

Complete syslog output can be found here: https://pastebin.ubuntu.com/p/tYTf8gh5ft/

Test output:
10:13:57 DEBUG| [stdout] Stress test: /home/ubuntu/autotest/client/tmp/ubuntu_ramfs_stress/src/stress-ng/stress-ng --verify --times --metrics-brief --syslog --keep-name -t 15s --hdd 4 --hdd-opts sync,wr-rnd,rd-rnd,fadv-willneed,fadv-rnd --link 4 --symlink 4 --lockf 4 --seek 4 --aio 4 --aio-requests 32 --dentry 4 --dir 4 --dentry-order stride --fallocate 4 --fstat 4 --dentries 65536 --io 1 --lease 4 --mmap 0 --mmap-file --mmap-async --open 4 --rename 4 --hdd-bytes 32M --fallocate-bytes 32M --chdir 4 --chmod 4 --filename 4 --rename 4 --mmap-bytes 32M --hdd-write-size 512
10:13:57 DEBUG| [stdout] Mount point: /mnt/ramfs-test-1002
10:13:57 DEBUG| [stdout] Date: Tue Jul 17 10:13:57 UTC 2018
10:13:57 DEBUG| [stdout] Host: harpo
10:13:57 DEBUG| [stdout] Kernel: 4.15.0-1011-kvm #11-Ubuntu SMP Fri May 25 08:24:07 UTC 2018
10:13:57 DEBUG| [stdout] Machine: harpo x86_64 x86_64
10:13:57 DEBUG| [stdout] CPUs online: 2
10:13:57 DEBUG| [stdout] CPUs total: 2
10:13:57 DEBUG| [stdout] Page size: 4096
10:13:57 DEBUG| [stdout] Pages avail: 216098
10:13:57 DEBUG| [stdout] Pages total: 255157
10:13:57 DEBUG| [stdout] --------------------------------------------------------------------------------
10:13:57 DEBUG| [stdout]
10:13:57 DEBUG| [stdout]
10:13:57 DEBUG| [stdout] stress-ng: info: [1024] dispatching hogs: 4 hdd, 4 link, 4 symlink, 4 lockf, 4 seek, 4 aio, 4 dentry, 4 dir, 4 fallocate, 4 fstat, 1 io, 4 lease, 2 mmap, 4 open, 4 rename, 4 chdir, 4 chmod, 4 filename, 4 rename
10:14:13 ERROR| Exception escaping from test:
Traceback (most recent call last):
  File "/home/ubuntu/autotest/client/shared/test.py", line 411, in _exec
    _call_test_function(self.execute, *p_args, **p_dargs)
  File "/home/ubuntu/autotest/client/shared/test.py", line 823, in _call_test_function
    return func(*args, **dargs)
  File "/home/ubuntu/autotest/client/shared/test.py", line 291, in execute
    postprocess_profiled_run, args, dargs)
  File "/home/ubuntu/autotest/client/shared/test.py", line 212, in _call_run_once
    self.run_once(*args, **dargs)
  File "/home/ubuntu/autotest/client/tests/ubuntu_ramfs_stress/ubuntu_ramfs_stress.py", line 70, in run_once
    self.results = utils.system_output(cmd, retain_output=True)
  File "/home/ubuntu/autotest/client/shared/utils.py", line 1267, in system_output
    verbose=verbose, args=args).stdout
  File "/home/ubuntu/autotest/client/shared/utils.py", line 918, in run
    "Command returned non-zero exit status")
CmdError: Command <LOG=/tmp/ramfs-falure.log STRESS_NG=/home/ubuntu/autotest/client/tmp/ubuntu_ramfs_stress/src/stress-ng/stress-ng DURATION=15s bash -c /home/ubuntu/autotest/client/tests/ubuntu_ramfs_stress/ubuntu_ramfs_stress.sh /home/ubuntu/autotest/client/tmp/ubuntu_ramfs_stress/src 2>&1> failed, rc=-9, Command returned non-zero exit status
* Command:
    LOG=/tmp/ramfs-falure.log
    STRESS_NG=/home/ubuntu/autotest/client/tmp/ubuntu_ramfs_stress/src/stress-
    ng/stress-ng DURATION=15s bash -c /home/ubuntu/autotest/client/tests/ubunt
    u_ramfs_stress/ubuntu_ramfs_stress.sh
    /home/ubuntu/autotest/client/tmp/ubuntu_ramfs_stress/src 2>&1
Exit status: -9
Duration: 15.3993020058

stdout:

--------------------------------------------------------------------------------
Stress test: /home/ubuntu/autotest/client/tmp/ubuntu_ramfs_stress/src/stress-ng/stress-ng --verify --times --metrics-brief --syslog --keep-name -t 15s --hdd 4 --hdd-opts sync,wr-rnd,rd-rnd,fadv-willneed,fadv-rnd --link 4 --symlink 4 --lockf 4 --seek 4 --aio 4 --aio-requests 32 --dentry 4 --dir 4 --dentry-order stride --fallocate 4 --fstat 4 --dentries 65536 --io 1 --lease 4 --mmap 0 --mmap-file --mmap-async --open 4 --rename 4 --hdd-bytes 32M --fallocate-bytes 32M --chdir 4 --chmod 4 --filename 4 --rename 4 --mmap-bytes 32M --hdd-write-size 512
Mount point: /mnt/ramfs-test-1002
Date: Tue Jul 17 10:13:57 UTC 2018
Host: harpo
Kernel: 4.15.0-1011-kvm #11-Ubuntu SMP Fri May 25 08:24:07 UTC 2018
Machine: harpo x86_64 x86_64
CPUs online: 2
CPUs total: 2
Page size: 4096
Pages avail: 216098
Pages total: 255157
--------------------------------------------------------------------------------

stress-ng: info: [1024] dispatching hogs: 4 hdd, 4 link, 4 symlink, 4 lockf, 4 seek, 4 aio, 4 dentry, 4 dir, 4 fallocate, 4 fstat, 1 io, 4 lease, 2 mmap, 4 open, 4 rename, 4 chdir, 4 chmod, 4 filename, 4 rename
10:14:14 ERROR| child process failed
10:14:14 DEBUG| Traceback (most recent call last):
10:14:14 DEBUG| File "/home/ubuntu/autotest/client/parallel.py", line 25, in fork_start
10:14:14 DEBUG| l()
10:14:14 DEBUG| File "/home/ubuntu/autotest/client/job.py", line 505, in <lambda>
10:14:14 DEBUG| l = lambda: test.runtest(self, url, tag, args, dargs)
10:14:14 DEBUG| File "/home/ubuntu/autotest/client/test.py", line 125, in runtest
10:14:14 DEBUG| job.sysinfo.log_after_each_iteration)
10:14:14 DEBUG| File "/home/ubuntu/autotest/client/shared/test.py", line 913, in runtest
10:14:14 DEBUG| mytest._exec(args, dargs)
10:14:14 DEBUG| File "/home/ubuntu/autotest/client/shared/test.py", line 411, in _exec
10:14:14 DEBUG| _call_test_function(self.execute, *p_args, **p_dargs)
10:14:14 DEBUG| File "/home/ubuntu/autotest/client/shared/test.py", line 823, in _call_test_function
10:14:14 DEBUG| return func(*args, **dargs)
10:14:14 DEBUG| File "/home/ubuntu/autotest/client/shared/test.py", line 291, in execute
10:14:14 DEBUG| postprocess_profiled_run, args, dargs)
10:14:14 DEBUG| File "/home/ubuntu/autotest/client/shared/test.py", line 212, in _call_run_once
10:14:14 DEBUG| self.run_once(*args, **dargs)
10:14:14 DEBUG| File "/home/ubuntu/autotest/client/tests/ubuntu_ramfs_stress/ubuntu_ramfs_stress.py", line 70, in run_once
10:14:14 DEBUG| self.results = utils.system_output(cmd, retain_output=True)
10:14:14 DEBUG| File "/home/ubuntu/autotest/client/shared/utils.py", line 1267, in system_output
10:14:14 DEBUG| verbose=verbose, args=args).stdout
10:14:14 DEBUG| File "/home/ubuntu/autotest/client/shared/utils.py", line 918, in run
10:14:14 DEBUG| "Command returned non-zero exit status")
10:14:14 DEBUG| CmdError: Command <LOG=/tmp/ramfs-falure.log STRESS_NG=/home/ubuntu/autotest/client/tmp/ubuntu_ramfs_stress/src/stress-ng/stress-ng DURATION=15s bash -c /home/ubuntu/autotest/client/tests/ubuntu_ramfs_stress/ubuntu_ramfs_stress.sh /home/ubuntu/autotest/client/tmp/ubuntu_ramfs_stress/src 2>&1> failed, rc=-9, Command returned non-zero exit status
10:14:14 DEBUG| * Command:
10:14:14 DEBUG| LOG=/tmp/ramfs-falure.log
10:14:14 DEBUG| STRESS_NG=/home/ubuntu/autotest/client/tmp/ubuntu_ramfs_stress/src/stress-
10:14:14 DEBUG| ng/stress-ng DURATION=15s bash -c /home/ubuntu/autotest/client/tests/ubunt
10:14:14 DEBUG| u_ramfs_stress/ubuntu_ramfs_stress.sh
10:14:14 DEBUG| /home/ubuntu/autotest/client/tmp/ubuntu_ramfs_stress/src 2>&1
10:14:14 DEBUG| Exit status: -9
10:14:14 DEBUG| Duration: 15.3993020058

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-4.15.0-1011-kvm 4.15.0-1011.11
ProcVersionSignature: User Name 4.15.0-1011.11-kvm 4.15.18
Uname: Linux 4.15.0-1011-kvm x86_64
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
Date: Tue Jul 17 10:15:29 2018
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=C.UTF-8
 SHELL=/bin/bash
SourcePackage: linux-kvm
UpgradeStatus: No upgrade log present (probably fresh install)

[Po-Hsu Lin (cypressyew)]

Patch applied
http://kernel.ubuntu.com/git/ubuntu/autotest-client-tests.git/commit/?id=b258273b1670d0623535fbf495f91f80b51f849a

Just need to check if this can be reproduced or not.

[Po-Hsu Lin (cypressyew)]

Tried several runs with a KVM node, it looks OK.

Marking the bug status to fix-released.