diff options
| -rw-r--r-- | tools/perf/Documentation/perf-top.txt | 9 | ||||
| -rw-r--r-- | tools/perf/builtin-top.c | 11 | ||||
| -rw-r--r-- | tools/perf/util/top.h | 1 |
3 files changed, 21 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt index 487737a725e9..20227dabc208 100644 --- a/tools/perf/Documentation/perf-top.txt +++ b/tools/perf/Documentation/perf-top.txt @@ -319,6 +319,15 @@ Default is to monitor all CPUS. go straight to the histogram browser, just like 'perf top' with no events explicitely specified does. +--stitch-lbr:: + Show callgraph with stitched LBRs, which may have more complete + callgraph. The option must be used with --call-graph lbr recording. + Disabled by default. In common cases with call stack overflows, + it can recreate better call stacks than the default lbr call stack + output. But this approach is not full proof. There can be cases + where it creates incorrect call stacks from incorrect matches. + The known limitations include exception handing such as + setjmp/longjmp will have calls/returns not match. INTERACTIVE PROMPTING KEYS -------------------------- diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 289cf83e658a..6b067a5ba1d5 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -33,6 +33,7 @@ #include "util/map.h" #include "util/mmap.h" #include "util/session.h" +#include "util/thread.h" #include "util/symbol.h" #include "util/synthetic-events.h" #include "util/top.h" @@ -775,6 +776,9 @@ static void perf_event__process_sample(struct perf_tool *tool, if (machine__resolve(machine, &al, sample) < 0) return; + if (top->stitch_lbr) + al.thread->lbr_stitch_enable = true; + if (!machine->kptr_restrict_warned && symbol_conf.kptr_restrict && al.cpumode == PERF_RECORD_MISC_KERNEL) { @@ -1571,6 +1575,8 @@ int cmd_top(int argc, const char **argv) "Sort the output by the event at the index n in group. " "If n is invalid, sort by the first event. " "WARNING: should be used on grouped events."), + OPT_BOOLEAN(0, "stitch-lbr", &top.stitch_lbr, + "Enable LBR callgraph stitching approach"), OPTS_EVSWITCH(&top.evswitch), OPT_END() }; @@ -1640,6 +1646,11 @@ int cmd_top(int argc, const char **argv) } } + if (top.stitch_lbr && !(callchain_param.record_mode == CALLCHAIN_LBR)) { + pr_err("Error: --stitch-lbr must be used with --call-graph lbr\n"); + goto out_delete_evlist; + } + if (opts->branch_stack && callchain_param.enabled) symbol_conf.show_branchflag_count = true; diff --git a/tools/perf/util/top.h b/tools/perf/util/top.h index f117d4f4821e..45dc84ddff37 100644 --- a/tools/perf/util/top.h +++ b/tools/perf/util/top.h @@ -36,6 +36,7 @@ struct perf_top { bool use_tui, use_stdio; bool vmlinux_warned; bool dump_symtab; + bool stitch_lbr; struct hist_entry *sym_filter_entry; struct evsel *sym_evsel; struct perf_session *session; |