Public bug reported:

With systemd-240 unity-greeter fails to start on most systems and always
fails on 32 bit.


According to systemd-dev,

"mlockall() is generally a bad idea and certainly has no place in a graphical 
program.
A program like this uses lots of memory and it is crucial that this memory can 
be paged
out to relieve memory pressure."

With systemd version 239 the ulimit for RLIMIT_MEMLOCK was set to 16 MiB
and therefore the mlockall call would fail. This is lucky becasue the 
subsequent mmap would not fail.

With systemd version 240 the RLIMIT_MEMLOCK is now set to 64 MiB
and now the mlockall no longer fails. However, it not possible to mmap in all
the memory and because that would still exceed the MEMLOCK limit.
"
See https://bugzilla.redhat.com/show_bug.cgi?id=1662857 &
https://github.com/CanonicalLtd/lightdm/issues/55

RLIMIT_MEMLOCK = 64 MiB means, unity-greeter will most likely fail with 64 bit 
and
will always fail on 32 bit systems.

Hence we better disable it.

** Affects: unity-greeter (Ubuntu)
     Importance: Undecided
         Status: Confirmed


** Tags: disco

** Branch linked: lp:~khurshid-alam/unity-greeter/systemd-240-fix

** Description changed:

+ With systemd-240 unity-greeter fails to start on most systems and always
+ fails on 32 bit.
+ 
+ 
  According to systemd-dev,
  
- "mlockall() is generally a bad idea and certainly has no place in a graphical 
program. 
- A program like this uses lots of memory and it is crucial that this memory 
can be paged 
+ "mlockall() is generally a bad idea and certainly has no place in a graphical 
program.
+ A program like this uses lots of memory and it is crucial that this memory 
can be paged
  out to relieve memory pressure."
  
- With systemd version 239 the ulimit for RLIMIT_MEMLOCK was set to 16 MiB 
+ With systemd version 239 the ulimit for RLIMIT_MEMLOCK was set to 16 MiB
  and therefore the mlockall call would fail. This is lucky becasue the 
subsequent mmap would not fail.
  
- With systemd version 240 the RLIMIT_MEMLOCK is now set to 64 MiB 
- and now the mlockall no longer fails. However, it not possible to mmap in all 
+ With systemd version 240 the RLIMIT_MEMLOCK is now set to 64 MiB
+ and now the mlockall no longer fails. However, it not possible to mmap in all
  the memory and because that would still exceed the MEMLOCK limit.
  "
  See https://bugzilla.redhat.com/show_bug.cgi?id=1662857 &
- https://github.com/CanonicalLtd/lightdm/issues/55    
+ https://github.com/CanonicalLtd/lightdm/issues/55
  
  RLIMIT_MEMLOCK = 64 MiB means, unity-greeter will most likely fail with 64 
bit and
- will always fail on 32 bit systems. 
+ will always fail on 32 bit systems.
  
  Hence we better disable it.

** Changed in: unity-greeter (Ubuntu)
       Status: New => Confirmed

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https://bugs.launchpad.net/bugs/1815493

Title:
  Disable mlockall() call for systemd-240

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