** Description changed:

  [SRU, Xenial]
  
  When running stress-ng on zVM and LPAR we are hitting SIGBUS errors
  because we have a sparsely allocated mmap'd backing file which due to
  over commit and a full file system causes pages not to be mapped in and
  causes memory accesses on unbacked pages to trigger a SIGBUS.
  
  [REPRODUCER + FIX]
  Run stress-ng --mmap 64 --maximize on a filesystem that is very nearly full 
and the SIGBUS triggers and the stressor exits early with SIGBUS.  With the 
fix, the SIGBUS is caught and the stressor can continue without premature early 
exit.
  
  [REGRESSION POTENTIAL]
  I am requesting syncing with 0.05.24 micro release as this contains the fix 
plus a few SIGSEGV stack trapping fixes.  stress-ng is a universe leaf project 
and the fixes touch just a few of the stress tests. These have been regression 
checked on various architectures and the code passes static analysis on 
cppcheck, CoverityScan and clang's scan-build, so regression potential is 
minimal.
- 
- Changelog:
- 
- Makefile: bump version
- stress-mmap: handle SIGBUS signals (LP: #1569468)
  
  
  --------------------------------------------------------------------------
  
  Running stress-ng on s390 in all three modes.  This seems to work ok in
  z/KVM, however, on zVM and LPAR as of a few days ago on Xenial the mmap
  stressor has started failing.
  
  I tried to get detailed logs but either don't know the correct switches
  or they simply aren't there.
  
  Here is the output when I used --log-file and --verbose on an LPAR:
  root@s1lp10-jefflane:~# less stress-ng-mmap-fail.log
  stress-ng: debug: [179421] 4 processors online, 4 processors configured
  stress-ng: info:  [179421] dispatching hogs: 4 mmap
  stress-ng: debug: [179421] cache allocate: reducing cache level from L3 (too 
high) to L2
  stress-ng: info:  [179421] cache allocate: default cache size: 2048K
  stress-ng: debug: [179421] starting stressors
  stress-ng: debug: [179422] stress-ng-mmap: started [179422] (instance 0)
  stress-ng: debug: [179423] stress-ng-mmap: started [179423] (instance 1)
  stress-ng: debug: [179424] stress-ng-mmap: started [179424] (instance 2)
  stress-ng: debug: [179421] 4 stressors spawned
  stress-ng: debug: [179425] stress-ng-mmap: started [179425] (instance 3)
  stress-ng: debug: [179424] stress-ng-mmap: exited [179424] (instance 2)
  stress-ng: debug: [179422] stress-ng-mmap: exited [179422] (instance 0)
  stress-ng: debug: [179421] process [179422] terminated
  stress-ng: debug: [179421] process 179423 (stress-ng-mmap) terminated on 
signal: 7 (Bus error)
  stress-ng: debug: [179421] process [179423] terminated
  stress-ng: debug: [179421] process [179424] terminated
  stress-ng: debug: [179421] process 179425 (stress-ng-mmap) terminated on 
signal: 7 (Bus error)
  stress-ng: debug: [179421] process [179425] terminated
  stress-ng: info:  [179421] unsuccessful run completed in 300.68s (5 mins, 
0.68 secs)
  
  That is the only info I have for the failure, unfortunately.
  
  ProblemType: Bug
  DistroRelease: Ubuntu 16.04
  Package: stress-ng 0.05.23-1
  ProcVersionSignature: Ubuntu 4.4.0-18.34-generic 4.4.6
  Uname: Linux 4.4.0-18-generic s390x
  ApportVersion: 2.20.1-0ubuntu1
  Architecture: s390x
  Date: Tue Apr 12 12:47:49 2016
  ProcEnviron:
   TERM=screen
   PATH=(custom, no user)
   XDG_RUNTIME_DIR=<set>
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  SourcePackage: stress-ng
  UpgradeStatus: No upgrade log present (probably fresh install)

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https://bugs.launchpad.net/bugs/1569468

Title:
  stress-ng mmap failing on zVM and LPAR

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