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authorAdrian Hunter <adrian.hunter@intel.com>2015-07-17 19:33:57 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2015-08-24 17:49:04 -0300
commitcc33618619cefc6d730cca3bb8e15311016a4da7 (patch)
tree251914f11eb7f672c6f19ff0d8f6dcb851b329b1 /tools/perf/arch/x86/util/intel-pt.c
parentb45fc0bfaf4a0b60ce2deda222f8ef2a23b89a5f (diff)
perf tools: Add Intel PT support for decoding CYC packets
CYC packets provide even finer grain timestamp information than MTC and TSC packets. A CYC packet contains the number of CPU cycles since the last CYC packet. This patch just adds decoder support. The CPU frequency can be related to TSC using the Maximum Non-Turbo Ratio in combination with the CBR (core-to-bus ratio) packet. However more accuracy is achieved by simply interpolating the number of cycles between other timing packets like MTC or TSC. This patch takes the latter approach. Support for a default value and validation of values is provided by a later patch. Also documentation is updated in a separate patch. For details refer to the June 2015 or later Intel 64 and IA-32 Architectures SDM Chapter 36 Intel Processor Trace. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/r/1437150840-31811-23-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/arch/x86/util/intel-pt.c')
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