From: James Clark <james.clark@linaro.org>
Date: Wed, 8 Jan 2025 14:28:59 +0000 (+0000)
Subject: perf tools arm-spe: Don't allocate buffer or tracking event in discard mode
X-Git-Tag: v6.14-rc1~120^2~29
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9c3164ea7e28a4a03c45868a089e98148bd51edf;p=thirdparty%2Flinux.git

perf tools arm-spe: Don't allocate buffer or tracking event in discard mode

The buffer will never be written to so don't bother allocating it. The
tracking event is also not required.

Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Graham Woodward <graham.woodward@arm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Veronika Molnarova <vmolnaro@redhat.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250108142904.401139-5-james.clark@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/tools/perf/arch/arm64/util/arm-spe.c b/tools/perf/arch/arm64/util/arm-spe.c
index 1b543855f2066..4301181b8e450 100644
--- a/tools/perf/arch/arm64/util/arm-spe.c
+++ b/tools/perf/arch/arm64/util/arm-spe.c
@@ -376,7 +376,7 @@ static int arm_spe_recording_options(struct auxtrace_record *itr,
 			container_of(itr, struct arm_spe_recording, itr);
 	struct evsel *evsel, *tmp;
 	struct perf_cpu_map *cpus = evlist->core.user_requested_cpus;
-
+	bool discard = false;
 	int err;
 
 	sper->evlist = evlist;
@@ -396,10 +396,17 @@ static int arm_spe_recording_options(struct auxtrace_record *itr,
 		return 0;
 
 	evlist__for_each_entry_safe(evlist, tmp, evsel) {
-		if (evsel__is_aux_event(evsel))
+		if (evsel__is_aux_event(evsel)) {
 			arm_spe_setup_evsel(evsel, cpus);
+			if (evsel->core.attr.config &
+			    perf_pmu__format_bits(evsel->pmu, "discard"))
+				discard = true;
+		}
 	}
 
+	if (discard)
+		return 0;
+
 	err = arm_spe_setup_aux_buffer(opts);
 	if (err)
 		return err;