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author | José Pekkarinen <jose.pekkarinen@nokia.com> | 2016-04-11 10:41:07 +0300 |
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committer | José Pekkarinen <jose.pekkarinen@nokia.com> | 2016-04-13 08:17:18 +0300 |
commit | e09b41010ba33a20a87472ee821fa407a5b8da36 (patch) | |
tree | d10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/tools/perf/Documentation/intel-bts.txt | |
parent | f93b97fd65072de626c074dbe099a1fff05ce060 (diff) |
These changes are the raw update to linux-4.4.6-rt14. Kernel sources
are taken from kernel.org, and rt patch from the rt wiki download page.
During the rebasing, the following patch collided:
Force tick interrupt and get rid of softirq magic(I70131fb85).
Collisions have been removed because its logic was found on the
source already.
Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'kernel/tools/perf/Documentation/intel-bts.txt')
-rw-r--r-- | kernel/tools/perf/Documentation/intel-bts.txt | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/kernel/tools/perf/Documentation/intel-bts.txt b/kernel/tools/perf/Documentation/intel-bts.txt new file mode 100644 index 000000000..8bdc93bd7 --- /dev/null +++ b/kernel/tools/perf/Documentation/intel-bts.txt @@ -0,0 +1,86 @@ +Intel Branch Trace Store +======================== + +Overview +======== + +Intel BTS could be regarded as a predecessor to Intel PT and has some +similarities because it can also identify every branch a program takes. A +notable difference is that Intel BTS has no timing information and as a +consequence the present implementation is limited to per-thread recording. + +While decoding Intel BTS does not require walking the object code, the object +code is still needed to pair up calls and returns correctly, consequently much +of the Intel PT documentation applies also to Intel BTS. Refer to the Intel PT +documentation and consider that the PMU 'intel_bts' can usually be used in +place of 'intel_pt' in the examples provided, with the proviso that per-thread +recording must also be stipulated i.e. the --per-thread option for +'perf record'. + + +perf record +=========== + +new event +--------- + +The Intel BTS kernel driver creates a new PMU for Intel BTS. The perf record +option is: + + -e intel_bts// + +Currently Intel BTS is limited to per-thread tracing so the --per-thread option +is also needed. + + +snapshot option +--------------- + +The snapshot option is the same as Intel PT (refer Intel PT documentation). + + +auxtrace mmap size option +----------------------- + +The mmap size option is the same as Intel PT (refer Intel PT documentation). + + +perf script +=========== + +By default, perf script will decode trace data found in the perf.data file. +This can be further controlled by option --itrace. The --itrace option is +the same as Intel PT (refer Intel PT documentation) except that neither +"instructions" events nor "transactions" events (and consequently call +chains) are supported. + +To disable trace decoding entirely, use the option --no-itrace. + + +dump option +----------- + +perf script has an option (-D) to "dump" the events i.e. display the binary +data. + +When -D is used, Intel BTS packets are displayed. + +To disable the display of Intel BTS packets, combine the -D option with +--no-itrace. + + +perf report +=========== + +By default, perf report will decode trace data found in the perf.data file. +This can be further controlled by new option --itrace exactly the same as +perf script. + + +perf inject +=========== + +perf inject also accepts the --itrace option in which case tracing data is +removed and replaced with the synthesized events. e.g. + + perf inject --itrace -i perf.data -o perf.data.new |