26/06/2018 11:23, David Hunt: > This patch set adds the capability to do out-of-band power > monitoring on a system. It uses a thread to monitor the branch > counters in the targeted cores, and calculates the branch ratio > if the running code. > > If the branch ratop is low (0.01), then > the code is most likely running in a tight poll loop and doing > nothing, i.e. receiving no packets. In this case we scale down > the frequency of that core. > > If the branch ratio is higher (>0.01), then it is likely that > the code is receiving and processing packets. In this case, we > scale up the frequency of that core. > > The cpu counters are read via /dev/cpu/x/msr, so requires the > msr kernel module to be loaded. Because this method is used, > the patch set is implemented with one file for x86 systems, and > another for non-x86 systems, with conditional compilation in > the Makefile. The non-x86 functions are stubs, and do not > currently implement any functionality. > > The vm_power_manager app has been modified to take a new parameter > --core-list or -l > which takes a list of cores in a comma-separated list format, > e.g. 1,3,5-7,9, which resolvest to a core list of 1,3,5,6,7,9 > These cores will then be enabled for oob monitoring. When the > OOB monitoring thread starts, it reads the branch hits/miss > counters of each monitored core, and scales up/down accordingly.
It looks to be a feature which could be integrated in DPDK libs. Why choosing to implement it fully in an example?
