---

   perf-intel-pt    ( 1 )

---

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

Below is an example of using Intel PT with autofdo. It requires autofdo (https://github.com/google/autofdo ) and gcc version 5. The bubble sort example is from the AutoFDO tutorial (https://gcc.gnu.org/wiki/AutoFDO/Tutorial ) amended to take the number of elements as a parameter.

$ gcc-5 -O3 sort.c -o sort_optimized $ ./sort_optimized 30000 Bubble sorting array of 30000 elements 2254 ms

$ cat ~/.perfconfig [intel-pt] mispred-all = on

$ perf record -e intel_pt//u ./sort 3000 Bubble sorting array of 3000 elements 58 ms [ perf record: Woken up 2 times to write data ] [ perf record: Captured and wrote 3.939 MB perf.data ] $ perf inject -i perf.data -o inj --itrace=i100usle --strip $ ./create_gcov --binary=./sort --profile=inj --gcov=sort.gcov -gcov_version=1 $ gcc-5 -O3 -fauto-profile=sort.gcov sort.c -o sort_autofdo $ ./sort_autofdo 30000 Bubble sorting array of 30000 elements 2155 ms

Note there is currently no advantage to using Intel PT instead of LBR, but that may change in the future if greater use is made of the data.