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Altera_Forum
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8 years ago

Error message during clCreateProgramWithBinary - WARNING: [acla10_ref0] NOT using DMA

I have a kernel that has been flashed on the a10gx board (Arria10 PCIe). I built the .aocx file with the aoc tool. I flashed the FPGA with aocl tool before executing the OpenCL application. My ...
Altera_Forum's avatar
Altera_Forum
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8 years ago

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Host/device data transfer via DMA needs the host buffer to be 64-byte-aligned or else DMA will not work and you will get those warnings. Please read "Intel® FPGA SDK for OpenCL Best Practices Guide, 1.3.4 Allocate Aligned Memory" for instructions as to how you can allocate aligned memory on the host.

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Hi, Thank you for the prompt feedback. I came across the documentation you mentioned at the end of last week. It would be good to have this specific memory allocation in the Hello World sample code.

I have IN/OUT buffers as parameters to the kernel. I had to use the posix_memalign() to fix the warning issue.