Commits
Adrian Hunter committed bc9b6bf07c8
perf tools: Add Intel PT support for PSB periods The PSB packet is a synchronization packet that provides a starting point for decoding or recovery from errors. This patch adds support for a new Intel PT feature that allows the frequency of PSB packets to be specified. Support for this feature is indicated by /sys/bus/event_source/devices/intel_pt/caps/psb_cyc which contains "1" if the feature is supported and "0" otherwise. The PSB period can be specified as a PMU config term e.g. perf record -e intel_pt/psb_period=2/u sleep 1 The default value is 3 or the nearest lower value that is supported. 0 is always supported. Valid values are given by: /sys/bus/event_source/devices/intel_pt/caps/psb_periods which contains a hexadecimal value, the bits of which represent valid values e.g. bit 2 set means value 2 is valid. The value is converted to the approximate number of trace bytes between PSB packets as: 2 ^ (value + 11) e.g. value 3 means 16KiB bytes between PSBs If an invalid value is entered, the error message will give a list of valid values e.g. $ perf record -e intel_pt/psb_period=15/u uname Invalid psb_period for intel_pt. Valid values are: 0-5 tools/perf/Documentation/intel-pt.txt is updated in a later patch as there are a number of new features being added. For more information about PSB periods refer to the Intel 64 and IA-32 Architectures SDM Chapter 36 Intel Processor Trace from June 2015 or later. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/r/1437150840-31811-18-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>