On Tue, 6 May 2014 12:34:45 +0300 Siarhei Siamashka <siarhei.siamas...@gmail.com> wrote:
> Implemented an automated script for running tests at different > operating points: > https://github.com/ssvb/cpuburn-arm/blob/master/cpufreq-ljt-stress-test And also added a script to parse the cpufreq tables from the sunxi-3.4 kernel to generate a plot picture via gnuplot: https://github.com/ssvb/cpuburn-arm/blob/547c229284f3/gnuplot-sunxi-cpufreq Using the cpufreq-ljt-stress-test script I have found the quasi-stable pairs of the CPU clock frequency and voltage for my A10-OLinuXino-LIME to populate the following table: #define SAFETY_MARGIN 0 /* should be set to at least 25 */ static struct cpufreq_dvfs sun4i_poorlime_dvfs_table[] = { {.freq = 1008000000, .volt = 1450 + SAFETY_MARGIN}, {.freq = 960000000, .volt = 1400 + SAFETY_MARGIN}, {.freq = 912000000, .volt = 1350 + SAFETY_MARGIN}, {.freq = 864000000, .volt = 1300 + SAFETY_MARGIN}, {.freq = 696000000, .volt = 1275 + SAFETY_MARGIN}, {.freq = 648000000, .volt = 1250 + SAFETY_MARGIN}, {.freq = 528000000, .volt = 1225 + SAFETY_MARGIN}, {.freq = 480000000, .volt = 1200 + SAFETY_MARGIN}, {.freq = 432000000, .volt = 1175 + SAFETY_MARGIN}, {.freq = 408000000, .volt = 1125 + SAFETY_MARGIN}, {.freq = 384000000, .volt = 1025 + SAFETY_MARGIN}, {.freq = 0, .volt = 1000}, /* end of cpu dvfs table */ }; Quasi-stable here means that the cpufreq-ljt-stress-test can run without failures for something like 10 minutes at each of these points, but increasing the clock frequency or decreasing the core voltage makes it fail. Surely, running longer may reveal that some of these operating points are actually not stable. And also we can't be sure that libjpeg-turbo is really the toughest possible workload one can find. So it makes sense to additionally increase the voltage by at least one extra step (0.025V) to have some safety margin. Anyway, the generated plot is attached ('sun4i_poorlime' represents the A10-OLinuXino-LIME cpufreq table that I tried to make). Anyone should be able to generate the same picture too by running: gnuplot-sunxi-cpufreq result.png \ arch/arm/mach-sun7i/cpu-freq/cpu-freq.c \ arch/arm/plat-sunxi/cpu-freq/cpu-freq-table.c \ some_file_with_sun4i_poorlime_dvfs_table.c -- Best regards, Siarhei Siamashka -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
