Hi everybody, Is DVFS for memory bus really working on Odroid XU3/4 board? Using a simple microbenchmark that is doing only memory accesses, memory DVFS seems to not working properly: The microbenchmark is doing pointer chasing by following index in an array. Indices in the array are set to follow a random pattern (cutting prefetcher), and forcing RAM access. git clone https://github.com/wwilly/benchmark.git \ && cd benchmark \ && source env.sh \ && ./bench_build.sh \ && bash source/scripts/test_dvfs_mem.sh Python 3, cmake and sudo rights are required. Results: DVFS CPU with performance governor mem_gov = simple_ondemand at 165000000 Hz in idle, should be bumped when the benchmark is running. - on the LITTLE cluster it takes 4.74308 s to run (683.004 c per memory access), - on the big cluster it takes 4.76556 s to run (980.343 c per moemory access). While forcing DVFS memory bus to use performance governor, mem_gov = performance at 825000000 Hz in idle, - on the LITTLE cluster it takes 1.1451 s to run (164.894 c per memory access), - on the big cluster it takes 1.18448 s to run (243.664 c per memory access). The kernel used is the last 5.7.5 stable with default exynos_defconfig. Cheers, Willy
