I am running PAR on a large design using a Linux machine with 4 Gb of memory. PAR runs out of memory even though only 2.3 Gb of memory were used.
What are the limiting factors for memory utilization on a Linux machine?
"(FATAL_ERROR:Portability:3 - This Xilinx application has run out of memory)."
Available application memory for a system with a standard kernel is calculated as:
(lesser of 4 Gb or your memory size) - 1 Gb (reserved for the kernel) - "overhead"
where the "overhead" is the size of the executable and linked libraries, typically around 700 Mb for PAR.
A 4 Gb Linux machine will have ~2.3 Gb available. This memory limitation can be increased by recompiling the kernel to reserve less than 1 Gb of memory; for example, if the kernel reserves 500 Mb, then PAR will have ~2.8 Gb of memory available.
See (Xilinx Answer 17445) for more details regarding kernel modifications.