Xilinx Alveo U280
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Software emulation of compute unit(s) exited unexpectedly
When emulating designs with medium to large local memory buffers, the stack size may not be sufficient, which leads to the above error message. There are different limits set on login nodes and all other nodes (in particular compute and fpga nodes) set.
Login nodes: a maximum of 8 MB stack size is possible. All of these 8 MB are usable for emulation by default. If this is not sufficient for your emulation, you need to allocate a compute or fpga node.
All other nodes: there is no hard limit except for the memory size you allocated for your job. By default, only 2 MB are usable for emulation (https://man7.org/linux/man-pages/man3/pthread_create.3.html). When this is insufficient, change the stack size inside your job to a fitting limit:
| Code Block |
|---|
# higher limit if needed, here 16 MB
ulimit -s 16384
# same 8 MB limit as on login nodes
ulimit -s 8192 |
Note that after setting a specific limit within a job, you can not increase it again, only further decrease it.
Note that for most designs that eventually should run in hardware, 8 MB is either approaching or already exceeding the limits of available on-chip memory resources. However, there can be use cases where higher limits are useful, for example when emulating multiple kernels together that should eventually run on separate FPGAs.
Intel Stratix 10
CL_INVALID_PROGRAM_EXECUTABLE with fast emulation
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