The branch counters logging (A.K.A LBR event logging) introduces a per-counter indication of precise event occurrences in LBRs. The kernel only dumps the number of occurrences into a record. The perf tool has to map the number to the corresponding event. Add evlist__update_br_cntr() to go through the evlist to pick the events that are configured to be logged. Assign a logical idx to track them, and add the total number of the events in the leader event. The total number will be used to allocate the space to save the branch counters for a block. The logical idx will be used to locate the corresponding event quickly in the following patches. It only needs to iterate the evlist once. The evsel__has_branch_counters() is also optimized. Reviewed-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: https://lore.kernel.org/r/20240813160208.2493643-4-kan.liang@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>