Cycle Measurement on ARM11platform using RVISS
Posted 06 August 2012 - 04:38 AM
Iam trying to measure the performance cycles for my application on RVISS ARM1176JZF-S platform.
When I measure the cycles it is giving 471977 cycle counts,
But measuring the same application performance on different machine it is giving 423787 cycle counts (lesser than my measurement).
For measuring the performance cycles on my machine, I followed some steps of settings:
MCCFG=1 in default.ami file and given ICACHE_LINES, DCACHE_LINES to 1024.
but sitll Iam getting difference of 48190 cycles, why this difference of cycles is getting in my machine?
Is I need to set more settings other than above?
Please help me in this.
Thanks in advance,
Posted 07 August 2012 - 04:17 AM
How are you measuring the cycles?
Iam using cycle count register to measure the cycles as below,
MRC p15, 0, r0, c15, c12, 1 ; Read cycle count register
and I want to measure the cycles with zero wait states(with out latencies), so though the RVISS is not cycle accurate, we need to benchmark with out latencies.
Posted 07 August 2012 - 07:12 AM
Not that this explains why CCNT reports different numbers on different workstations. Best guess would be a difference in configuration. When you connect to RVISS it prints a load of config information to the debugger console. Have you compared these on both machines?