On 18/09/17 08:39, Simon Horman wrote: > On Wed, Aug 30, 2017 at 03:41:20PM +0100, Dietmar Eggemann wrote: >> The following 'capacity-dmips-mhz' dt property values are used: >> >> Cortex-A15: 1024, Cortex-A7: 539 >> >> They have been derived form the cpu_efficiency values: >> >> Cortex-A15: 3891, Cortex-A7: 2048 >> >> by scaling them so that the Cortex-A15s (big cores) use 1024. >> >> The cpu_efficiency values were originally derived from the "Big.LITTLE >> Processing with ARM Cortex™-A15 & Cortex-A7" white paper >> (http://www.cl.cam.ac.uk/~rdm34/big.LITTLE.pdf). Table 1 lists 1.9x >> (3891/2048) as the Cortex-A15 vs Cortex-A7 performance ratio for the >> Dhrystone benchmark. >> >> The following platform is affected once cpu-invariant accounting >> support is re-connected to the task scheduler: > > Thanks, applied for v4.15. > > My understanding from the following comment in the cover letter is that not > currently the case and this there is no behavioural change in applying this > patch. > > For the record I observed the following with and without this patch > applied. I believe this is the expected result. > > v4.14-rc1 > # cat /sys/devices/system/cpu/cpu*/cpu_capacity > 1535 > 1535 > 1535 > 1535 > 1024 > 1024 > 1024 > 1024 > > v4.14-rc1 + patch > # cat /sys/devices/system/cpu/cpu*/cpu_capacity > 1024 > 1024 > 1024 > 1024 > 539 > 539 > 539 > 539 Thanks Simon! Yes, that is the expected behaviour. And sorry for not responding earlier! With exynos542{0,2} and r8a7790 switching to the 'capacity-dmips-mhz' based solution in v4.15, I can push for removal of the cpu_efficency code [patch 1/4]. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
