03-30-2019, 12:07 PM
Yes, I have the same problem with mainline kernels from 4.18 to 5.0. The scheduler assigns mostly A53 cores and few times A72 when I try a load of only one process.
Regarding the performance, I use "stress-ng -cpu 1 --timeout 10 --metrics-brief" to test (and "schedtool" to force CPU affinity), and, with kernels 4.4, I get
~30 bogomips for A53 and
~58 bogomips for A72.
With kernels 4.18-5.0 I get
~44 bogomips for A72.
Moreover, when I use "userspace" governor and set the speed manually I get
~44 bogomips for 1800 MHz,
~44 bogomips for 1608 MHz,
~43 bogomips for 1416 MHz,
~12 bogomips for 408 MHz.
Stranger still is that if I modify the device trees to change 1800000000 Hz to 2080000000 I get
~50 bogomips. WTF is happening here?
Regarding the performance, I use "stress-ng -cpu 1 --timeout 10 --metrics-brief" to test (and "schedtool" to force CPU affinity), and, with kernels 4.4, I get
~30 bogomips for A53 and
~58 bogomips for A72.
With kernels 4.18-5.0 I get
~44 bogomips for A72.
Moreover, when I use "userspace" governor and set the speed manually I get
~44 bogomips for 1800 MHz,
~44 bogomips for 1608 MHz,
~43 bogomips for 1416 MHz,
~12 bogomips for 408 MHz.
Stranger still is that if I modify the device trees to change 1800000000 Hz to 2080000000 I get
~50 bogomips. WTF is happening here?