migration target error

[MDreamChaser]

Hi, developers, when I run the system, I have come across troubles. On migration target, vmem_load.py can not work because src/dst mapping differ. I find the src.maps do not match with dst.maps

[srinskit]

You might have to disable ASLR (Address Space Layout Randomization).

echo 0 | sudo tee /proc/sys/kernel/randomize_va_space

[MDreamChaser]

I run the system in two machines, the src.maps is always differ from dst.maps, though echo 0 | sudo tee /proc/sys/kernel/randomize_va_space.

[srinskit]

Is the OS identical between the two machines?

[MDreamChaser]

yes, all is ubuntu 4.15

[MDreamChaser]

I run the printer process sparately both in machine A and B,then migrate A.printer to B via ipaddress. However the maps are differ

[srinskit]

Please share the src and dst mappings from /proc/src_pid/maps and /proc/dst_pid/maps.

[MDreamChaser]

how to share, I have a little knowledge of it

[srinskit]

src_pid is the PID of the source process
dst_pid is the PID of the destination process
Execute cat /proc/src_pid/maps and cat /proc/dst_pid/maps and share screenshots of the output.

[MDreamChaser]

dst

[MDreamChaser]

src

[srinskit]

Confirming: Did you run echo 0 | sudo tee /proc/sys/kernel/randomize_va_space on both machines before starting the processes?

[MDreamChaser]

now, I run echo 0 | sudo tee /proc/sys/kernel/randomize_va_space on both machines.two maps still do not match

[srinskit]

This is a lot better. I am not sure why the mapping is mismatched just for one section.

For a quick dirty fix, you can make the below changes to state_tools/vmem_load.py

1. Remove assert checking for mapping difference.
2. Add a check to skip copying unlabelled sections before here.

    if line.find("[") == -1 and line.find("/") == -1:
      continue 
   

[srinskit]

You could also consult Ubuntu/Linux forums on why the mappings differ without ASLR. I can look into it after the holidays.

[MDreamChaser]

thank you very much