This improves the documentation of the various perf_event_open() related sysfs files. Signed-off-by: Vince Weaver <vincent.weaver@xxxxxxxxx> diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2 index 504e801..e7ddcb2 100644 --- a/man2/perf_event_open.2 +++ b/man2/perf_event_open.2 @@ -1926,6 +1926,7 @@ The default value is Maximum number of pages an unprivileged user can mlock (2) . The default is 516 (kB). + .RE Files in .I /sys/bus/event_source/devices/ @@ -1936,30 +1937,59 @@ Information on how to program these PMUs can be found under .IR /sys/bus/event_source/devices/ . Each subdirectory corresponds to a different PMU. .TP -.I /sys/bus/event_source/devices/*/type +.IR /sys/bus/event_source/devices/*/type " (Since Linux 2.6.38)" This contains an integer that can be used in the .I type field of perf_event_attr to indicate you wish to use this PMU. .TP -.I /sys/bus/event_source/devices/*/rdpmc -[To be documented] +.IR /sys/bus/event_source/devices/*/rdpmc " (Since Linux 3.4)" +If this file is 1, then direct user-space access to the +performance counter registers is allowed via the rdpmc instruction. +This can be disabled by echoing 0 to the file. .TP -.I /sys/bus/event_source/devices/*/format/ -This sub-directory contains information on what bits in the +.IR /sys/bus/event_source/devices/*/format/ " (Since Linux 3.4)" +This sub-directory contains information on the architecture-specific +sub-fields available for programming the various .I config -field of perf_event_attr correspond to. -.TP -.I /sys/bus/event_source/devices/*/events/ +fields in the perf_event_attr struct. + +The content of each file is the name of the config field, followed +by a colon, followed by a series of integer bit ranges separated by +commas. +For example, the file +.I event +may contain the value +.I config1:1,6-10,44 +which indicates that event is an attribute that occupies bits 1,6-10, and 44 +of perf_event_attr::config1. +.TP +.IR /sys/bus/event_source/devices/*/events/ " (Since Linux 3.4)" This sub-directory contains files with pre-defined events. The contents are strings describing the event settings -expressed in terms of the fields found in the +expressed in terms of the fields found in the previously mentioned .I ./format/ directory. These are not necessarily complete lists of all events supported by a PMU, but usually a subset of events deemed useful or interesting. + +The content of each file is a list of attribute names +separated by commas. +Each entry has an optional value (either hex or decimal). +If no value is specified than it is assumed to be a single-bit +field with a value of 1. +An example entry may look like this: +.I event=0x2,inv,ldlat=3 .TP .I /sys/bus/event_source/devices/*/uevent -[To be documented] +This file is the standard kernel device interface +for injecting hotplug events. +.TP +.IR /sys/bus/event_source/devices/*/cpumask " (Since Linux 3.7)" +The cpumask file contains a comma-separated list of integers that +indicate a representative cpu number for each socket (package) +on the motherboard. +This is needed when setting up uncore or northbridge events, as +those PMUs present socket-wide events. .RE .SH RETURN VALUE .BR perf_event_open () -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
