From f8ccc2d5cc6516b019bcf8e361ae2a380cb36019 Mon Sep 17 00:00:00 2001
From: Leo Yan <leo.yan@linaro.org>
Date: Sat, 14 Oct 2023 15:41:58 +0800
Subject: [PATCH] perf cs-etm: Validate timestamp tracing in per-thread mode
So far, it's impossible to validate timestamp trace in Arm CoreSight when
the perf is in the per-thread mode. E.g. for the command:
perf record -e cs_etm/timestamp/ --per-thread -- ls
The command enables config 'timestamp' for 'cs_etm' event in the
per-thread mode. In this case, the function cs_etm_validate_config()
directly bails out and skips validation.
Given profiled process can be scheduled on any CPUs in the per-thread
mode, this patch validates timestamp tracing for all CPUs when detect
the CPU map is empty.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: James Clark <james.clark@arm.com>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: coresight@lists.linaro.org
Link: https://lore.kernel.org/r/20231014074159.1667880-2-leo.yan@linaro.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/arch/arm/util/cs-etm.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
index 16bba74f048bf..39ec6cae91edb 100644
--- a/tools/perf/arch/arm/util/cs-etm.c
+++ b/tools/perf/arch/arm/util/cs-etm.c
@@ -205,8 +205,17 @@ static int cs_etm_validate_config(struct auxtrace_record *itr,
for (i = 0; i < cpu__max_cpu().cpu; i++) {
struct perf_cpu cpu = { .cpu = i, };
- if (!perf_cpu_map__has(event_cpus, cpu) ||
- !perf_cpu_map__has(online_cpus, cpu))
+ /*
+ * In per-cpu case, do the validation for CPUs to work with.
+ * In per-thread case, the CPU map is empty. Since the traced
+ * program can run on any CPUs in this case, thus don't skip
+ * validation.
+ */
+ if (!perf_cpu_map__empty(event_cpus) &&
+ !perf_cpu_map__has(event_cpus, cpu))
+ continue;
+
+ if (!perf_cpu_map__has(online_cpus, cpu))
continue;
err = cs_etm_validate_context_id(itr, evsel, i);
--
2.30.2