Hi, On 23.05.2018 06:19, Seokhee Han wrote: >> The results of portwell seems more than just bad - they same >> unbelievable, the error is VERY high (2msec). >> >> I've tried to find a benchmark which can support my results, but found >> no benchmark with ATOM. > I am now developing RT Linux system on minnowboard Turbot Quad Core board, > which adopts ATOM E3845 series SoC, and it shows above about 2ms worst-case > latency during cyclictest. So I try to detect SMI-related, kernel unaware, > hw latency using Linux kernel's hwlat tracer and it tells me that there are > couples of latency spikes (above 1000us) on the board. FWIW, I played a while with a MinnowBoard too. As it turns out the firmware provided from Intel is just no good for -rt. I ended up building a firmware with coreboot. With coreboot all the 2-3ms spikes were gone. Unfortunately, building your own firmware for the MinnowBoard is far from easy though possible: https://3mdeb.com/firmware/building-coreboot-on-minnowboard/ Thanks, Daniel -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
