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The parallelism level can be shown in reports on its own, and to calculate latency overheads. Signed-off-by: Dmitry Vyukov Cc: Namhyung Kim Cc: Arnaldo Carvalho de Melo Cc: Ian Rogers Cc: linux-perf-users@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- tools/perf/builtin-report.c | 1 + tools/perf/util/addr_location.c | 1 + tools/perf/util/addr_location.h | 2 ++ tools/perf/util/event.c | 3 +++ tools/perf/util/machine.c | 7 +++++++ tools/perf/util/machine.h | 6 ++++++ 6 files changed, 20 insertions(+) diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c index f5fbd670d619a..0d9bd090eda71 100644 --- a/tools/perf/builtin-report.c +++ b/tools/perf/builtin-report.c @@ -1568,6 +1568,7 @@ int cmd_report(int argc, const char **argv) report.tool.cgroup =3D perf_event__process_cgroup; report.tool.exit =3D perf_event__process_exit; report.tool.fork =3D perf_event__process_fork; + report.tool.context_switch =3D perf_event__process_switch; report.tool.lost =3D perf_event__process_lost; report.tool.read =3D process_read_event; report.tool.attr =3D process_attr; diff --git a/tools/perf/util/addr_location.c b/tools/perf/util/addr_locatio= n.c index 51825ef8c0ab7..007a2f5df9a6a 100644 --- a/tools/perf/util/addr_location.c +++ b/tools/perf/util/addr_location.c @@ -17,6 +17,7 @@ void addr_location__init(struct addr_location *al) al->cpumode =3D 0; al->cpu =3D 0; al->socket =3D 0; + al->parallelism =3D 1; } =20 /* diff --git a/tools/perf/util/addr_location.h b/tools/perf/util/addr_locatio= n.h index d8ac0428dff23..36aaa45445f24 100644 --- a/tools/perf/util/addr_location.h +++ b/tools/perf/util/addr_location.h @@ -21,6 +21,8 @@ struct addr_location { u8 cpumode; s32 cpu; s32 socket; + /* Same as machine.parallelism but within [1, nr_cpus]. */ + int parallelism; }; =20 void addr_location__init(struct addr_location *al); diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c index aac96d5d19170..3d3ac58e1c660 100644 --- a/tools/perf/util/event.c +++ b/tools/perf/util/event.c @@ -767,6 +767,9 @@ int machine__resolve(struct machine *machine, struct ad= dr_location *al, al->socket =3D env->cpu[al->cpu].socket_id; } =20 + /* Account for possible out-of-order switch events. */ + al->parallelism =3D min(max(machine->parallelism, 1), machine__nr_cpus_av= ail(machine)); + if (al->map) { if (symbol_conf.dso_list && (!dso || !(strlist__has_entry(symbol_conf.dso_list, diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index 2d51badfbf2e2..0e65c5377f983 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -94,6 +94,8 @@ int machine__init(struct machine *machine, const char *ro= ot_dir, pid_t pid) machine->comm_exec =3D false; machine->kernel_start =3D 0; machine->vmlinux_map =3D NULL; + /* There is no initial context switch in, so we start at 1. */ + machine->parallelism =3D 1; =20 machine->root_dir =3D strdup(root_dir); if (machine->root_dir =3D=3D NULL) @@ -677,8 +679,11 @@ int machine__process_aux_output_hw_id_event(struct mac= hine *machine __maybe_unus int machine__process_switch_event(struct machine *machine __maybe_unused, union perf_event *event) { + bool out =3D event->header.misc & PERF_RECORD_MISC_SWITCH_OUT; + if (dump_trace) perf_event__fprintf_switch(event, stdout); + machine->parallelism +=3D out ? -1 : 1; return 0; } =20 @@ -1900,6 +1905,8 @@ int machine__process_exit_event(struct machine *machi= ne, union perf_event *event if (dump_trace) perf_event__fprintf_task(event, stdout); =20 + /* There is no context switch out before exit, so we decrement here. */ + machine->parallelism--; if (thread !=3D NULL) { if (symbol_conf.keep_exited_threads) thread__set_exited(thread, /*exited=3D*/true); diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h index 2e5a4cb342d82..a5f28652873ce 100644 --- a/tools/perf/util/machine.h +++ b/tools/perf/util/machine.h @@ -50,6 +50,12 @@ struct machine { u64 text_start; u64 text_end; } sched, lock, traceiter, trace; + /* + * The current parallelism level (number of threads that run on CPUs). + * This value can be less than 1, or larger than the total number + * of CPUs, if events are poorly ordered. + */ + int parallelism; pid_t *current_tid; size_t current_tid_sz; union { /* Tool specific area */ --=20 2.48.1.362.g079036d154-goog