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Altera_Forum
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7 years ago

Limiting the number of threads on NDRange kernels

Hi, Is there a way to limit the number of simultaneous executing threads for a ndrange kernel?? My NDRange kernel has a high thread capacity (127 simultaneous threads) and uses local me...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
7 years ago

Thanks HRZ, 


ap_uint<32>  lra_regs;
ap_uint<32>  lra_big_regs;

I get the following feedback from the early report.

lra_big_regs, lra_regs:

Requested size 5460 bytes

Implemented size 2080768 bytes

Number of banks 16

Bank width 32 bits

Bank depth 128 words

Total replication 254

Additional Information

Replicated 254 times to efficiently support multiple simultaneous workgroups

Running memory at 2x clock to support more concurrent ports

Actually , it correctly describes the requested size, but replicates memories by a factor 254 !! Ending (in this case) with a BRAM estimate of 180%.

It looks like the compiler (trying to increase the performance) is not aware that it is replicating too much hardware, and there is no way to stop him from doing it.