Re: [PATCH v10 18/29] perf timechart: Don't pass evsel with sample

Namhyung Kim
2026-04-12T20:13:32Z

On Sat, Apr 11, 2026 at 07:08:21PM -0700, Ian Rogers wrote:
> The sample contains the evsel and so it is unnecessary to pass the
> evsel as well. Add missing backtrace argument to tracepoint_handler
> functions and mark them unused. Fix missing free from cat_backtrace,
> which requires copies of the backtrace being made in functions that
> save it.

I've splitted the backtrace handling part into a new commit.

Thanks,
Namhyung

>
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
> tools/perf/builtin-timechart.c | 81 ++++++++++++++++------------------
> 1 file changed, 39 insertions(+), 42 deletions(-)
>
> diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
> index 034e0ba3f9cb..64f69bd67c6b 100644
> --- a/tools/perf/builtin-timechart.c
> +++ b/tools/perf/builtin-timechart.c
> @@ -299,7 +299,7 @@ static void pid_put_sample(struct timechart *tchart, int pid, int type,
> sample->type = type;
> sample->next = c->samples;
> sample->cpu = cpu;
> - sample->backtrace = backtrace;
> + sample->backtrace = backtrace ? strdup(backtrace) : NULL;
> c->samples = sample;
>
> if (sample->type == TYPE_RUNNING && end > start && start > 0) {
> @@ -433,7 +433,7 @@ static void sched_wakeup(struct timechart *tchart, int cpu, u64 timestamp,
>
> we->time = timestamp;
> we->waker = waker;
> - we->backtrace = backtrace;
> + we->backtrace = backtrace ? strdup(backtrace) : NULL;
>
> if ((flags & TRACE_FLAG_HARDIRQ) || (flags & TRACE_FLAG_SOFTIRQ))
> we->waker = -1;
> @@ -489,9 +489,9 @@ static void sched_switch(struct timechart *tchart, int cpu, u64 timestamp,
> }
> }
>
> -static const char *cat_backtrace(union perf_event *event,
> - struct perf_sample *sample,
> - struct machine *machine)
> +static char *cat_backtrace(union perf_event *event,
> + struct perf_sample *sample,
> + struct machine *machine)
> {
> struct addr_location al;
> unsigned int i;
> @@ -544,8 +544,10 @@ static const char *cat_backtrace(union perf_event *event,
> * It seems the callchain is corrupted.
> * Discard all.
> */
> - zfree(&p);
> - goto exit;
> + addr_location__exit(&al);
> + fclose(f);
> + free(p);
> + return NULL;
> }
> continue;
> }
> @@ -567,7 +569,6 @@ static const char *cat_backtrace(union perf_event *event,
> }
>
> typedef int (*tracepoint_handler)(struct timechart *tchart,
> - struct evsel *evsel,
> struct perf_sample *sample,
> const char *backtrace);
>
> @@ -578,6 +579,7 @@ static int process_sample_event(const struct perf_tool *tool,
> {
> struct timechart *tchart = container_of(tool, struct timechart, tool);
> struct evsel *evsel = sample->evsel;
> + int ret = 0;
>
> if (evsel->core.attr.sample_type & PERF_SAMPLE_TIME) {
> if (!tchart->first_time || tchart->first_time > sample->time)
> @@ -588,16 +590,17 @@ static int process_sample_event(const struct perf_tool *tool,
>
> if (evsel->handler != NULL) {
> tracepoint_handler f = evsel->handler;
> - return f(tchart, evsel, sample,
> - cat_backtrace(event, sample, machine));
> + char *backtrace = cat_backtrace(event, sample, machine);
> +
> + ret = f(tchart, sample, backtrace);
> + free(backtrace);
> }
>
> - return 0;
> + return ret;
> }
>
> static int
> process_sample_cpu_idle(struct timechart *tchart __maybe_unused,
> - struct evsel *evsel __maybe_unused,
> struct perf_sample *sample,
> const char *backtrace __maybe_unused)
> {
> @@ -613,7 +616,6 @@ process_sample_cpu_idle(struct timechart *tchart __maybe_unused,
>
> static int
> process_sample_cpu_frequency(struct timechart *tchart,
> - struct evsel *evsel __maybe_unused,
> struct perf_sample *sample,
> const char *backtrace __maybe_unused)
> {
> @@ -626,7 +628,6 @@ process_sample_cpu_frequency(struct timechart *tchart,
>
> static int
> process_sample_sched_wakeup(struct timechart *tchart,
> - struct evsel *evsel __maybe_unused,
> struct perf_sample *sample,
> const char *backtrace)
> {
> @@ -640,7 +641,6 @@ process_sample_sched_wakeup(struct timechart *tchart,
>
> static int
> process_sample_sched_switch(struct timechart *tchart,
> - struct evsel *evsel __maybe_unused,
> struct perf_sample *sample,
> const char *backtrace)
> {
> @@ -656,7 +656,6 @@ process_sample_sched_switch(struct timechart *tchart,
> #ifdef SUPPORT_OLD_POWER_EVENTS
> static int
> process_sample_power_start(struct timechart *tchart __maybe_unused,
> - struct evsel *evsel __maybe_unused,
> struct perf_sample *sample,
> const char *backtrace __maybe_unused)
> {
> @@ -669,7 +668,6 @@ process_sample_power_start(struct timechart *tchart __maybe_unused,
>
> static int
> process_sample_power_end(struct timechart *tchart,
> - struct evsel *evsel __maybe_unused,
> struct perf_sample *sample,
> const char *backtrace __maybe_unused)
> {
> @@ -679,7 +677,6 @@ process_sample_power_end(struct timechart *tchart,
>
> static int
> process_sample_power_frequency(struct timechart *tchart,
> - struct evsel *evsel __maybe_unused,
> struct perf_sample *sample,
> const char *backtrace __maybe_unused)
> {
> @@ -849,8 +846,8 @@ static int pid_end_io_sample(struct timechart *tchart, int pid, int type,
>
> static int
> process_enter_read(struct timechart *tchart,
> - struct evsel *evsel __maybe_unused,
> - struct perf_sample *sample)
> + struct perf_sample *sample,
> + const char *backtrace __maybe_unused)
> {
> long fd = perf_sample__intval(sample, "fd");
> return pid_begin_io_sample(tchart, sample->tid, IOTYPE_READ,
> @@ -859,8 +856,8 @@ process_enter_read(struct timechart *tchart,
>
> static int
> process_exit_read(struct timechart *tchart,
> - struct evsel *evsel __maybe_unused,
> - struct perf_sample *sample)
> + struct perf_sample *sample,
> + const char *backtrace __maybe_unused)
> {
> long ret = perf_sample__intval(sample, "ret");
> return pid_end_io_sample(tchart, sample->tid, IOTYPE_READ,
> @@ -869,8 +866,8 @@ process_exit_read(struct timechart *tchart,
>
> static int
> process_enter_write(struct timechart *tchart,
> - struct evsel *evsel __maybe_unused,
> - struct perf_sample *sample)
> + struct perf_sample *sample,
> + const char *backtrace __maybe_unused)
> {
> long fd = perf_sample__intval(sample, "fd");
> return pid_begin_io_sample(tchart, sample->tid, IOTYPE_WRITE,
> @@ -879,8 +876,8 @@ process_enter_write(struct timechart *tchart,
>
> static int
> process_exit_write(struct timechart *tchart,
> - struct evsel *evsel __maybe_unused,
> - struct perf_sample *sample)
> + struct perf_sample *sample,
> + const char *backtrace __maybe_unused)
> {
> long ret = perf_sample__intval(sample, "ret");
> return pid_end_io_sample(tchart, sample->tid, IOTYPE_WRITE,
> @@ -889,8 +886,8 @@ process_exit_write(struct timechart *tchart,
>
> static int
> process_enter_sync(struct timechart *tchart,
> - struct evsel *evsel __maybe_unused,
> - struct perf_sample *sample)
> + struct perf_sample *sample,
> + const char *backtrace __maybe_unused)
> {
> long fd = perf_sample__intval(sample, "fd");
> return pid_begin_io_sample(tchart, sample->tid, IOTYPE_SYNC,
> @@ -899,8 +896,8 @@ process_enter_sync(struct timechart *tchart,
>
> static int
> process_exit_sync(struct timechart *tchart,
> - struct evsel *evsel __maybe_unused,
> - struct perf_sample *sample)
> + struct perf_sample *sample,
> + const char *backtrace __maybe_unused)
> {
> long ret = perf_sample__intval(sample, "ret");
> return pid_end_io_sample(tchart, sample->tid, IOTYPE_SYNC,
> @@ -909,8 +906,8 @@ process_exit_sync(struct timechart *tchart,
>
> static int
> process_enter_tx(struct timechart *tchart,
> - struct evsel *evsel __maybe_unused,
> - struct perf_sample *sample)
> + struct perf_sample *sample,
> + const char *backtrace __maybe_unused)
> {
> long fd = perf_sample__intval(sample, "fd");
> return pid_begin_io_sample(tchart, sample->tid, IOTYPE_TX,
> @@ -919,8 +916,8 @@ process_enter_tx(struct timechart *tchart,
>
> static int
> process_exit_tx(struct timechart *tchart,
> - struct evsel *evsel __maybe_unused,
> - struct perf_sample *sample)
> + struct perf_sample *sample,
> + const char *backtrace __maybe_unused)
> {
> long ret = perf_sample__intval(sample, "ret");
> return pid_end_io_sample(tchart, sample->tid, IOTYPE_TX,
> @@ -929,8 +926,8 @@ process_exit_tx(struct timechart *tchart,
>
> static int
> process_enter_rx(struct timechart *tchart,
> - struct evsel *evsel __maybe_unused,
> - struct perf_sample *sample)
> + struct perf_sample *sample,
> + const char *backtrace __maybe_unused)
> {
> long fd = perf_sample__intval(sample, "fd");
> return pid_begin_io_sample(tchart, sample->tid, IOTYPE_RX,
> @@ -939,8 +936,8 @@ process_enter_rx(struct timechart *tchart,
>
> static int
> process_exit_rx(struct timechart *tchart,
> - struct evsel *evsel __maybe_unused,
> - struct perf_sample *sample)
> + struct perf_sample *sample,
> + const char *backtrace __maybe_unused)
> {
> long ret = perf_sample__intval(sample, "ret");
> return pid_end_io_sample(tchart, sample->tid, IOTYPE_RX,
> @@ -949,8 +946,8 @@ process_exit_rx(struct timechart *tchart,
>
> static int
> process_enter_poll(struct timechart *tchart,
> - struct evsel *evsel __maybe_unused,
> - struct perf_sample *sample)
> + struct perf_sample *sample,
> + const char *backtrace __maybe_unused)
> {
> long fd = perf_sample__intval(sample, "fd");
> return pid_begin_io_sample(tchart, sample->tid, IOTYPE_POLL,
> @@ -959,8 +956,8 @@ process_enter_poll(struct timechart *tchart,
>
> static int
> process_exit_poll(struct timechart *tchart,
> - struct evsel *evsel __maybe_unused,
> - struct perf_sample *sample)
> + struct perf_sample *sample,
> + const char *backtrace __maybe_unused)
> {
> long ret = perf_sample__intval(sample, "ret");
> return pid_end_io_sample(tchart, sample->tid, IOTYPE_POLL,
> --
> 2.53.0.1213.gd9a14994de-goog
>