[lammps-users] memory errors happens

Dear lammps users,

I wirte the in file, but still errors happens, as “Failed to allocate ******* bytes for array neigh:binhead” or " Failed to allocate****** bytes for array atoms :binhead"
I am not sure how to fix these problems when modifying the code.

what I want to do is to simulate a cylinder channel and let molecule pass through the channel with LJ potentials between wall and pass molecules.
can any one help me?

thanks,
Qi

Those messages occur b/c you are running out of physical
memory. Nothing you can do about that except run a smaller
problem or use more processors.

Steve

Dear lammps users,

I wirte the in file, but still errors happens, as "Failed to
allocate ******* bytes for array neigh:binhead" or " Failed to
allocate****** bytes for array atoms :binhead"
I am not sure how to fix these problems when modifying the code.

your system is "exploding" and due to using shrink wrap boundary
conditions, the box size and its storage requirements are growing
until the variable counting the number of bytes to be allocated overflows.

you should have a closer look at the system that you are building.

axel.

Those messages occur b/c you are running out of physical

correction. it is not physical memory issue here, but the first argument
to Memory::smalloc() wraps around due to being a signed integer.

if you would use a size_t type there (and the code leading up to it), you
could go on and then lammps would crash when one runs out of address
space (not physical memory).

most unix/linux systems allow overcommitment and map unused
memory to the same physical location with a 'copy-on-write' flag.
if overcommitment is not allowed then you run out of memory when
you exhaust physical _and_ swap memory.

that doesn't make the input in question run any better, but just to
avoid some misunderstandings about memory management
and where the problem is originating from.

cheers,
    axel.