perf arm-spe: Enable timestamp for per-cpu mode

For per-cpu mmap, it should enable timestamp tracing for Arm SPE; this
is helpful for samples correlation.

To automatically enable the timestamp, a helper arm_spe_set_timestamp()
is introduced for setting "ts_enable" format bit.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: James Clark <james.clark@arm.com>
Tested-by: James Clark <james.clark@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Al Grant <Al.Grant@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210519041546.1574961-4-leo.yan@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 4c91662..bacdf36 100644 (file)
--- a/tools/perf/arch/arm64/util/arm-spe.c
+++ b/tools/perf/arch/arm64/util/arm-spe.c
@@ -14,6 +14,7 @@
 #include "../../../util/cpumap.h"
 #include "../../../util/event.h"
 #include "../../../util/evsel.h"
+#include "../../../util/evsel_config.h"
 #include "../../../util/evlist.h"
 #include "../../../util/session.h"
 #include <internal/lib.h> // page_size
@@ -32,6 +33,29 @@ struct arm_spe_recording {
        struct evlist           *evlist;
 };
 
+static void arm_spe_set_timestamp(struct auxtrace_record *itr,
+                                 struct evsel *evsel)
+{
+       struct arm_spe_recording *ptr;
+       struct perf_pmu *arm_spe_pmu;
+       struct evsel_config_term *term = evsel__get_config_term(evsel, CFG_CHG);
+       u64 user_bits = 0, bit;
+
+       ptr = container_of(itr, struct arm_spe_recording, itr);
+       arm_spe_pmu = ptr->arm_spe_pmu;
+
+       if (term)
+               user_bits = term->val.cfg_chg;
+
+       bit = perf_pmu__format_bits(&arm_spe_pmu->format, "ts_enable");
+
+       /* Skip if user has set it */
+       if (bit & user_bits)
+               return;
+
+       evsel->core.attr.config |= bit;
+}
+
 static size_t
 arm_spe_info_priv_size(struct auxtrace_record *itr __maybe_unused,
                       struct evlist *evlist __maybe_unused)
@@ -121,9 +145,14 @@ static int arm_spe_recording_options(struct auxtrace_record *itr,
         */
        evlist__to_front(evlist, arm_spe_evsel);
 
-       /* In the case of per-cpu mmaps, sample CPU for AUX event. */
-       if (!perf_cpu_map__empty(cpus))
+       /*
+        * In the case of per-cpu mmaps, sample CPU for AUX event;
+        * also enable the timestamp tracing for samples correlation.
+        */
+       if (!perf_cpu_map__empty(cpus)) {
                evsel__set_sample_bit(arm_spe_evsel, CPU);
+               arm_spe_set_timestamp(itr, arm_spe_evsel);
+       }
 
        /* Add dummy event to keep tracking */
        err = parse_events(evlist, "dummy:u", NULL);