It is often useful to know the branch types while analyzing branch data. For example, a call is very different from a conditional branch.
Currently we have to look it up in binary while the binary may later not be available and even the binary is available but user has to take some time. It is very useful for user to check it directly in perf report. Perf already has support for disassembling the branch instruction to get the branch type. The patch series records the branch type and show the branch type with other LBR information in callchain entry via perf report. The patch series also adds the branch type summary at the end of perf report --stdio. To keep consistent on kernel and userspace and make the classification more common, the patch adds the common branch type classification in perf_event.h. The common branch types are: JCC forward: Conditional forward jump JCC backward: Conditional backward jump JMP: Jump imm IND_JMP: Jump reg/mem CALL: Call imm IND_CALL: Call reg/mem RET: Ret FAR_BRANCH: SYSCALL/SYSRET, IRQ, IRET, TSX Abort An example: 1. Record branch type (new option "save_type") perf record -g --branch-filter any,save_type <command> 2. Show the branch type statistics at the end of perf report --stdio perf report --stdio JCC forward: 34.0% JCC backward: 3.6% JMP: 0.0% IND_JMP: 6.5% CALL: 26.6% IND_CALL: 0.0% RET: 29.3% FAR_BRANCH: 0.0% 3. Show branch type in callchain entry perf report --branch-history --stdio --no-children --23.91%--main div.c:42 (RET cycles:2) compute_flag div.c:28 (RET cycles:2) compute_flag div.c:27 (RET cycles:1) rand rand.c:28 (RET cycles:1) rand rand.c:28 (RET cycles:1) __random random.c:298 (RET cycles:1) __random random.c:297 (JCC forward cycles:1) __random random.c:295 (JCC forward cycles:1) __random random.c:295 (JCC forward cycles:1) __random random.c:295 (JCC forward cycles:1) __random random.c:295 (RET cycles:9) Jin Yao (5): perf/core: Define the common branch type classification perf/x86/intel: Record branch type perf record: Create a new option save_type in --branch-filter perf report: Show branch type statistics for stdio mode perf report: Show branch type in callchain entry arch/x86/events/intel/lbr.c | 69 ++++++++++++- include/uapi/linux/perf_event.h | 24 ++++- tools/include/uapi/linux/perf_event.h | 24 ++++- tools/perf/Documentation/perf-record.txt | 1 + tools/perf/builtin-report.c | 140 ++++++++++++++++++++++++++ tools/perf/util/callchain.c | 168 ++++++++++++++++++++----------- tools/perf/util/callchain.h | 13 +++ tools/perf/util/event.h | 3 +- tools/perf/util/hist.c | 5 +- tools/perf/util/parse-branch-options.c | 1 + 10 files changed, 381 insertions(+), 67 deletions(-) -- 2.7.4