AM625: DMA memory to memory transfer benchmark

Koichiro Tashiro

Part Number: AM625

Hi,

My customer wants to know memory to memory (DDR to DDR) transfer performance with DMA.
Their scenario is moving ~8MB of image data block using DMA.

Below document provides LMBench benchmark and
"bw_mem-cp-8mb (MB/s)" and "bw_mem-fcp-8mb (MB/s)" seem similar scenario as what the customer expects.
https://software-dl.ti.com/processor-sdk-linux/esd/AM62X/08_03_00_19/exports/docs/devices/AM62X/linux/Linux_Performance_Guide.html

The customer wants to know what bw_mem-cp-*mb(MB/s) and bw_mem-fcp-*mb (MB/s) are doing.
Do you have any documents which describes these benchmark in details?

Thanks and regards,
Koichiro Tashiro

over 2 years ago

0 Kallikuppa Sreenivasa over 2 years ago

TI__Guru**** 168184 points

Hello Koichiro Tashiro

Thank you for the query.

Let me check with the design team and update you.

Regards,

Sreenivasa

0 Kallikuppa Sreenivasa over 2 years ago in reply to Kallikuppa Sreenivasa

TI__Guru**** 168184 points

Hello Koichiro Tashiro,

Please refer inputs from the design team

LMbench is industry std: https://lmbench.sourceforge.net/

LMbench is cpu based mem to mem tests to measure memory b/w

We don't have DMA based tests with linux.

Regards,

Sreenivasa

0 Koichiro Tashiro over 2 years ago in reply to Kallikuppa Sreenivasa

TI__Mastermind 22350 points

Hi Sreenivasa,

Thanks for your quick reply.
Could you double check below point?

Kallikuppa Sreenivasa said:
LMbench is cpu based mem to mem tests to measure memory b/w

We don't have DMA based tests with linux.

I got these LMBench results from BU team as DMA performance.
I will forward the e-mail offline.

Thanks and regards,
Koichiro Tashiro

0 Kallikuppa Sreenivasa over 2 years ago in reply to Koichiro Tashiro

TI__Guru**** 168184 points

Hello Koichiro Tashiro

Thank you for the note.

received your inputs. I will check with the design team.

Is there any additional queries you have for me to check.

Regards,

Sreenivasa

+1 Kallikuppa Sreenivasa over 2 years ago in reply to Kallikuppa Sreenivasa

TI__Guru**** 168184 points

Hello Koichiro Tashiro,

I summarized our discussion for reference.

do we have any DMA transfer performance data available?
OS does not matter.

No. We do not have anything measured on RTOS.

I added some additional inputs i could get from the design team.

LMbench is industry std:

https://lmbench.sourceforge.net/

LMBench is not DMA test but just measure of how fast CPU can move data with DDR, it does different strides (all documented in above site) ... We dont have DMA tests in linux

ethernet performance is indirect measure of DMA performance as we use DMA to move data from ethernet to DDR.

But DDR to DDR DMA copy could be (many folds) faster (Ethernet can generate traffic at 2Gbps bidirectional at max)

Regards,

Sreenivasa

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AM625: DMA memory to memory transfer benchmark