On Tue, Aug 28, 2018 at 11:11:02AM +0800, Jin, Yao wrote: > Hi, > > The upstream kernel has supported IIO free-running counters on Skylake > server. As of Skylake Server, there are a number of free running counters in > each IIO Box that collect counts of per-box IO clocks and per-port > Input/Output x BW/Utilization. > > There are three types of IIO free-running counters on Skylake server: > > 1. IO CLOCKS counter: a clock of IIO box. > > 2. BANDWIDTH counters: count inbound(PCIe->CPU)/outbound(CPU->PCIe) > bandwidth. > > 3. UTILIZATION counters: count input/output utilization. > > With these IIO free-running counters, we can get good observation for IIO > traffic on Skylake server. For example, we can see the IIO inbound bandwidth > (PCIe->CPU). > > root@skx /sys/devices# perf stat -a -e > uncore_iio_free_running_2/bw_in_port0/ > ^C > Performance counter stats for 'system wide': > > 153.19 MiB uncore_iio_free_running_2/bw_in_port0/ > > 8.037701069 seconds time elapsed > > I propose to backport the patches which support IIO free-running counters to > 4.14 stable kernel. > > perf/x86/intel/uncore: Introduce customized event_read() for client IMC > uncore > 2da331465f44f9618abe8837d1a68405d550b66e > > perf/x86/intel/uncore: Add new data structures for free running counters > 927b2deb067b8b4753fc09c7a42092f43fc0c1f6 > > perf/x86/intel/uncore: Add infrastructure for free running counters > 0e0162dfcd1fbe4c711ee86f24f966c318999603 > > perf/x86/intel/uncore: Support IIO free-running counters on SKX > 0f519f0352e37e7d71bdce5559517c74a35f6e33 > > perf/x86/intel/uncore: Expose uncore_pmu_event*() functions > 5a6c9d94e9ed7410142bc6fcb638a4db1895aa0c > > perf/x86/intel/uncore: Clean up client IMC uncore > 9aae1780e7e81e54edfb70ba33ead5b0b48be009 Where in the stable kernel rules does it say that these types of patches are ok to be backported? Why not just use a newer kernel release if you want to use these new features? What is preventing these users from using 4.18 or newer? thanks, greg k-h
