Memory leak using shared arrays on cluster?

Hello everyone,

I see the following strange behavior starting multiple processes on a KNL node with Julia 1.0.1. I add some processes using addprocs(SYS.CPU_THREADS, topology=:master_worker). Already that consumes roughly a fourth of the available memory (25 out of 96GB). In my code I now allocate a large shared array (~10^6 elements) and compute its entries (just multiplications and sums, there should not be any further allocations). My job now hangs when sharing the array or when trying to iterate over it via @sync @distributed. During that period memory consumption grows until a bus error occurs and the job cancels.

The same code runs fine on my local machine with 4 cores, with memory consumption stable.

Any ideas where that may come from? Anyone can reproduce something similar with a shared array of similar size and many processes?

Start by reproducing the reported behavior on a KNL node with Julia 1.0.1, using addprocs(SYS.CPU_THREADS, topology=:master_worker), a large shared array, and @sync @distributed. Compare memory usage with the local four-core case and isolate whether sharing or iteration triggers the growth. Done means the cause is identified and the shared-array computation no longer hangs or ends in a bus error.