[PATCH v6 03/25] perf sample: Add evsel to struct perf_sample

Ian Rogers
2026-04-04T03:43:42Z

Add the evsel from evsel__parse_sample into the struct
perf_sample. Sometimes we want to alter the evsel associated with a
sample, such as with off-cpu bpf-output events. In general the evsel
and perf_sample are passed as a pair, but this makes an altered evsel
something of a chore to keep checking for and setting up. Later
patches will remove passing an evsel with the perf_sample and switch
to just using the perf_sample's value.

Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/builtin-inject.c | 6 +++---
tools/perf/builtin-script.c | 4 ++++
tools/perf/tests/hists_cumulate.c | 2 +-
tools/perf/tests/hists_filter.c | 1 +
tools/perf/tests/hists_output.c | 2 +-
tools/perf/util/evsel.c | 1 +
tools/perf/util/sample.c | 1 +
tools/perf/util/sample.h | 3 +++
tools/perf/util/session.c | 35 +++++++++++++++++++------------
9 files changed, 37 insertions(+), 18 deletions(-)

diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index d63191ae4c5b..05b769a2a825 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -133,7 +133,7 @@ struct perf_inject {
struct perf_file_section secs[HEADER_FEAT_BITS];
struct guest_session guest_session;
struct strlist *known_build_ids;
- const struct evsel *mmap_evsel;
+ struct evsel *mmap_evsel;
struct ip_callchain *raw_callchain;
};

@@ -519,7 +519,7 @@ static struct dso *findnew_dso(int pid, int tid, const char *filename,
* processing mmap events. If not stashed, search the evlist for the first mmap
* gathering event.
*/
-static const struct evsel *inject__mmap_evsel(struct perf_inject *inject)
+static struct evsel *inject__mmap_evsel(struct perf_inject *inject)
{
struct evsel *pos;

@@ -1023,7 +1023,6 @@ int perf_event__inject_buildid(const struct perf_tool *tool, union perf_event *e

sample__for_each_callchain_node(thread, evsel, sample, PERF_MAX_STACK_DEPTH,
/*symbols=*/false, mark_dso_hit_callback, &args);
-
thread__put(thread);
repipe:
perf_event__repipe(tool, event, sample, machine);
@@ -1432,6 +1431,7 @@ static int synthesize_build_id(struct perf_inject *inject, struct dso *dso, pid_
{
struct machine *machine = perf_session__findnew_machine(inject->session, machine_pid);
struct perf_sample synth_sample = {
+ .evsel = inject__mmap_evsel(inject),
.pid = -1,
.tid = -1,
.time = -1,
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 622130d3aed4..42d4cc162039 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -2910,8 +2910,12 @@ static int print_event_with_time(const struct perf_tool *tool,
thread = machine__findnew_thread(machine, pid, tid);

if (evsel) {
+ struct evsel *saved_evsel = sample->evsel;
+
+ sample->evsel = evsel;
perf_sample__fprintf_start(script, sample, thread, evsel,
event->header.type, stdout);
+ sample->evsel = saved_evsel;
}

perf_event__fprintf(event, machine, stdout);
diff --git a/tools/perf/tests/hists_cumulate.c b/tools/perf/tests/hists_cumulate.c
index 3eb9ef8d7ec6..606aa926a8fc 100644
--- a/tools/perf/tests/hists_cumulate.c
+++ b/tools/perf/tests/hists_cumulate.c
@@ -81,7 +81,7 @@ static int add_hist_entries(struct hists *hists, struct machine *machine)
{
struct addr_location al;
struct evsel *evsel = hists_to_evsel(hists);
- struct perf_sample sample = { .period = 1000, };
+ struct perf_sample sample = { .evsel = evsel, .period = 1000, };
size_t i;

addr_location__init(&al);
diff --git a/tools/perf/tests/hists_filter.c b/tools/perf/tests/hists_filter.c
index 1cebd20cc91c..cc6b26e373d1 100644
--- a/tools/perf/tests/hists_filter.c
+++ b/tools/perf/tests/hists_filter.c
@@ -70,6 +70,7 @@ static int add_hist_entries(struct evlist *evlist,
};
struct hists *hists = evsel__hists(evsel);

+ sample.evsel = evsel;
/* make sure it has no filter at first */
hists->thread_filter = NULL;
hists->dso_filter = NULL;
diff --git a/tools/perf/tests/hists_output.c b/tools/perf/tests/hists_output.c
index ee5ec8bda60e..7818950d786e 100644
--- a/tools/perf/tests/hists_output.c
+++ b/tools/perf/tests/hists_output.c
@@ -51,7 +51,7 @@ static int add_hist_entries(struct hists *hists, struct machine *machine)
{
struct addr_location al;
struct evsel *evsel = hists_to_evsel(hists);
- struct perf_sample sample = { .period = 100, };
+ struct perf_sample sample = { .evsel = evsel, .period = 100, };
size_t i;

addr_location__init(&al);
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index df2392713edb..2ee87fd84d3e 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -3226,6 +3226,7 @@ int evsel__parse_sample(struct evsel *evsel, union perf_event *event,
union u64_swap u;

perf_sample__init(data, /*all=*/true);
+ data->evsel = evsel;
data->cpu = data->pid = data->tid = -1;
data->stream_id = data->id = data->time = -1ULL;
data->period = evsel->core.attr.sample_period;
diff --git a/tools/perf/util/sample.c b/tools/perf/util/sample.c
index 2a30de4573f6..cf73329326d7 100644
--- a/tools/perf/util/sample.c
+++ b/tools/perf/util/sample.c
@@ -19,6 +19,7 @@ void perf_sample__init(struct perf_sample *sample, bool all)
if (all) {
memset(sample, 0, sizeof(*sample));
} else {
+ sample->evsel = NULL;
sample->user_regs = NULL;
sample->intr_regs = NULL;
sample->merged_callchain = false;
diff --git a/tools/perf/util/sample.h b/tools/perf/util/sample.h
index 5809c42631e5..3bd6d8b60586 100644
--- a/tools/perf/util/sample.h
+++ b/tools/perf/util/sample.h
@@ -5,6 +5,7 @@
#include <linux/perf_event.h>
#include <linux/types.h>

+struct evsel;
struct machine;
struct thread;

@@ -102,6 +103,8 @@ struct simd_flags {
* and clean up these values.
*/
struct perf_sample {
+ /** @evsel: Backward reference to the evsel used when constructing the sample. */
+ struct evsel *evsel;
/** @ip: The sample event PERF_SAMPLE_IP value. */
u64 ip;
/** @pid: The sample event PERF_SAMPLE_TID pid value. */
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 53fb2e628b71..7588cca110d2 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1264,8 +1264,9 @@ static int deliver_sample_value(struct evlist *evlist,
bool per_thread)
{
struct perf_sample_id *sid = evlist__id2sid(evlist, v->id);
- struct evsel *evsel;
+ struct evsel *saved_evsel = sample->evsel;
u64 *storage = NULL;
+ int ret;

if (sid) {
storage = perf_sample_id__get_period_storage(sid, sample->tid, per_thread);
@@ -1289,8 +1290,10 @@ static int deliver_sample_value(struct evlist *evlist,
if (!sample->period)
return 0;

- evsel = container_of(sid->evsel, struct evsel, core);
- return tool->sample(tool, event, sample, evsel, machine);
+ sample->evsel = container_of(sid->evsel, struct evsel, core);
+ ret = tool->sample(tool, event, sample, sample->evsel, machine);
+ sample->evsel = saved_evsel;
+ return ret;
}

static int deliver_sample_group(struct evlist *evlist,
@@ -1362,13 +1365,16 @@ static int evlist__deliver_deferred_callchain(struct evlist *evlist,
struct machine *machine)
{
struct deferred_event *de, *tmp;
- struct evsel *evsel;
int ret = 0;

if (!tool->merge_deferred_callchains) {
- evsel = evlist__id2evsel(evlist, sample->id);
- return tool->callchain_deferred(tool, event, sample,
- evsel, machine);
+ struct evsel *saved_evsel = sample->evsel;
+
+ sample->evsel = evlist__id2evsel(evlist, sample->id);
+ ret = tool->callchain_deferred(tool, event, sample,
+ sample->evsel, machine);
+ sample->evsel = saved_evsel;
+ return ret;
}

list_for_each_entry_safe(de, tmp, &evlist->deferred_samples, list) {
@@ -1392,9 +1398,9 @@ static int evlist__deliver_deferred_callchain(struct evlist *evlist,
else
orig_sample.deferred_callchain = false;

- evsel = evlist__id2evsel(evlist, orig_sample.id);
+ orig_sample.evsel = evlist__id2evsel(evlist, orig_sample.id);
ret = evlist__deliver_sample(evlist, tool, de->event,
- &orig_sample, evsel, machine);
+ &orig_sample, orig_sample.evsel, machine);

perf_sample__exit(&orig_sample);
list_del(&de->list);
@@ -1417,7 +1423,6 @@ static int session__flush_deferred_samples(struct perf_session *session,
struct evlist *evlist = session->evlist;
struct machine *machine = &session->machines.host;
struct deferred_event *de, *tmp;
- struct evsel *evsel;
int ret = 0;

list_for_each_entry_safe(de, tmp, &evlist->deferred_samples, list) {
@@ -1431,9 +1436,9 @@ static int session__flush_deferred_samples(struct perf_session *session,
break;
}

- evsel = evlist__id2evsel(evlist, sample.id);
+ sample.evsel = evlist__id2evsel(evlist, sample.id);
ret = evlist__deliver_sample(evlist, tool, de->event,
- &sample, evsel, machine);
+ &sample, sample.evsel, machine);

perf_sample__exit(&sample);
list_del(&de->list);
@@ -1458,8 +1463,12 @@ static int machines__deliver_event(struct machines *machines,

dump_event(evlist, event, file_offset, sample, file_path);

- evsel = evlist__id2evsel(evlist, sample->id);
+ if (!sample->evsel)
+ sample->evsel = evlist__id2evsel(evlist, sample->id);
+ else
+ assert(sample->evsel == evlist__id2evsel(evlist, sample->id));

+ evsel = sample->evsel;
machine = machines__find_for_cpumode(machines, event, sample);

switch (event->header.type) {
--
2.53.0.1213.gd9a14994de-goog