Commit 1a9d080d authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
Browse files

perf callchain: Add a for_each callback style API 



Add a for_each callback style API to callchain with
sample__for_each_callchain_node().

Possibly in the future such an API can avoid the overhead of
constructing the call chain list.

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Casey Chen <cachen@purestorage.com>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Link: https://lore.kernel.org/r/20240812224119.744968-1-irogers@google.com


[ Split from a larger patch that introduced the API and use it ]
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent b2738fda

tools/perf/util/callchain.c

+35 −0
Original line number Diff line number Diff line
@@ -1797,3 +1797,38 @@ s64 callchain_avg_cycles(struct callchain_node *cnode) 


	return cycles;

}



int sample__for_each_callchain_node(struct thread *thread, struct evsel *evsel,

				    struct perf_sample *sample, int max_stack,

				    callchain_iter_fn cb, void *data)

{

	struct callchain_cursor *cursor = get_tls_callchain_cursor();

	int ret;



	if (!cursor)

		return -ENOMEM;



	/* Fill in the callchain. */

	ret = thread__resolve_callchain(thread, cursor, evsel, sample,

					/*parent=*/NULL, /*root_al=*/NULL,

					max_stack);

	if (ret)

		return ret;



	/* Switch from writing the callchain to reading it. */

	callchain_cursor_commit(cursor);



	while (1) {

		struct callchain_cursor_node *node = callchain_cursor_current(cursor);



		if (!node)

			break;



		ret = cb(node, data);

		if (ret)

			return ret;



		callchain_cursor_advance(cursor);

	}

	return 0;

}

tools/perf/util/callchain.h

+6 −0
Original line number Diff line number Diff line
@@ -311,4 +311,10 @@ u64 callchain_total_hits(struct hists *hists); 


s64 callchain_avg_cycles(struct callchain_node *cnode);



typedef int (*callchain_iter_fn)(struct callchain_cursor_node *node, void *data);



int sample__for_each_callchain_node(struct thread *thread, struct evsel *evsel,

				    struct perf_sample *sample, int max_stack,

				    callchain_iter_fn cb, void *data);



#endif	/* __PERF_CALLCHAIN_H */