What: /sys/devices/cpu/events/ /sys/devices/cpu/events/branch-misses /sys/devices/cpu/events/cache-references /sys/devices/cpu/events/cache-misses /sys/devices/cpu/events/stalled-cycles-frontend /sys/devices/cpu/events/branch-instructions /sys/devices/cpu/events/stalled-cycles-backend /sys/devices/cpu/events/instructions /sys/devices/cpu/events/cpu-cycles Date: 2013/01/08 Contact: Linux kernel mailing list Description: Generic performance monitoring events A collection of performance monitoring events that may be supported by many/most CPUs. These events can be monitored using the 'perf(1)' tool. The contents of each file would look like: event=0xNNNN where 'N' is a hex digit and the number '0xNNNN' shows the "raw code" for the perf event identified by the file's "basename". What: /sys/bus/event_source/devices//events/ Date: 2014/02/24 Contact: Linux kernel mailing list Description: Per-pmu performance monitoring events specific to the running system Each file (except for some of those with a '.' in them, '.unit' and '.scale') in the 'events' directory describes a single performance monitoring event supported by the . The name of the file is the name of the event. As performance monitoring event names are case insensitive in the perf tool, the perf tool only looks for lower or upper case event names in sysfs to avoid scanning the directory. It is therefore required the name of the event here is either lower or upper case. File contents: [=][,[=]]... Where is one of the terms listed under /sys/bus/event_source/devices//format/ and is a number is base-16 format with a '0x' prefix (lowercase only). If a is specified alone (without an assigned value), it is implied that 0x1 is assigned to that . Examples (each of these lines would be in a separate file): event=0x2abc event=0x423,inv,cmask=0x3 domain=0x1,offset=0x8,starting_index=0xffff domain=0x1,offset=0x8,core=? Each of the assignments indicates a value to be assigned to a particular set of bits (as defined by the format file corresponding to the ) in the perf_event structure passed to the perf_open syscall. In the case of the last example, a value replacing "?" would need to be provided by the user selecting the particular event. This is referred to as "event parameterization". Event parameters have the format 'param=?'. What: /sys/bus/event_source/devices//events/.unit Date: 2014/02/24 Contact: Linux kernel mailing list Description: Perf event units A string specifying the English plural numerical unit that (once multiplied by .scale) represents. Example: Joules What: /sys/bus/event_source/devices//events/.scale Date: 2014/02/24 Contact: Linux kernel mailing list Description: Perf event scaling factors A string representing a floating point value expressed in scientific notation to be multiplied by the event count received from the kernel to match the unit specified in the .unit file. Example: 2.3283064365386962890625e-10 This is provided to avoid performing floating point arithmetic in the kernel.