[PATCH] perf tools: cs-etm: Properly deal with cpu maps

From: Mathieu Poirier
Date: Fri Dec 15 2017 - 13:11:26 EST


This patch allows the CoreSight header file to fit topologies where only
a subset of all available CPUs are present, avoiding at the same time
accessing the ETM configuration areas of CPUs that have been offlined.

Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
---
tools/perf/arch/arm/util/cs-etm.c | 51 +++++++++++++++++++++++++++------------
1 file changed, 36 insertions(+), 15 deletions(-)

diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
index fbfc055d3f4d..5c655ad4621e 100644
--- a/tools/perf/arch/arm/util/cs-etm.c
+++ b/tools/perf/arch/arm/util/cs-etm.c
@@ -298,12 +298,17 @@ cs_etm_info_priv_size(struct auxtrace_record *itr __maybe_unused,
{
int i;
int etmv3 = 0, etmv4 = 0;
- const struct cpu_map *cpus = evlist->cpus;
+ struct cpu_map *event_cpus = evlist->cpus;
+ struct cpu_map *online_cpus = cpu_map__new(NULL);

/* cpu map is not empty, we have specific CPUs to work with */
- if (!cpu_map__empty(cpus)) {
- for (i = 0; i < cpu_map__nr(cpus); i++) {
- if (cs_etm_is_etmv4(itr, cpus->map[i]))
+ if (!cpu_map__empty(event_cpus)) {
+ for (i = 0; i < cpu__max_cpu(); i++) {
+ if (!cpu_map__has(event_cpus, i) ||
+ !cpu_map__has(online_cpus, i))
+ continue;
+
+ if (cs_etm_is_etmv4(itr, i))
etmv4++;
else
etmv3++;
@@ -311,6 +316,9 @@ cs_etm_info_priv_size(struct auxtrace_record *itr __maybe_unused,
} else {
/* get configuration for all CPUs in the system */
for (i = 0; i < cpu__max_cpu(); i++) {
+ if (!cpu_map__has(online_cpus, i))
+ continue;
+
if (cs_etm_is_etmv4(itr, i))
etmv4++;
else
@@ -318,6 +326,8 @@ cs_etm_info_priv_size(struct auxtrace_record *itr __maybe_unused,
}
}

+ cpu_map__put(online_cpus);
+
return (CS_ETM_HEADER_SIZE +
(etmv4 * CS_ETMV4_PRIV_SIZE) +
(etmv3 * CS_ETMV3_PRIV_SIZE));
@@ -447,7 +457,9 @@ static int cs_etm_info_fill(struct auxtrace_record *itr,
int i;
u32 offset;
u64 nr_cpu, type;
- const struct cpu_map *cpus = session->evlist->cpus;
+ struct cpu_map *cpu_map;
+ struct cpu_map *event_cpus = session->evlist->cpus;
+ struct cpu_map *online_cpus = cpu_map__new(NULL);
struct cs_etm_recording *ptr =
container_of(itr, struct cs_etm_recording, itr);
struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
@@ -458,8 +470,21 @@ static int cs_etm_info_fill(struct auxtrace_record *itr,
if (!session->evlist->nr_mmaps)
return -EINVAL;

- /* If the cpu_map is empty all CPUs are involved */
- nr_cpu = cpu_map__empty(cpus) ? cpu__max_cpu() : cpu_map__nr(cpus);
+ /* If the cpu_map is empty all online CPUs are involved */
+ if (cpu_map__empty(event_cpus)) {
+ cpu_map = online_cpus;
+ } else {
+ /* Make sure all specified CPUs are online */
+ for (i = 0; i < cpu_map__nr(event_cpus); i++) {
+ if (cpu_map__has(event_cpus, i) &&
+ !cpu_map__has(online_cpus, i))
+ return -EINVAL;
+ }
+
+ cpu_map = event_cpus;
+ }
+
+ nr_cpu = cpu_map__nr(cpu_map);
/* Get PMU type as dynamically assigned by the core */
type = cs_etm_pmu->type;

@@ -472,15 +497,11 @@ static int cs_etm_info_fill(struct auxtrace_record *itr,

offset = CS_ETM_SNAPSHOT + 1;

- /* cpu map is not empty, we have specific CPUs to work with */
- if (!cpu_map__empty(cpus)) {
- for (i = 0; i < cpu_map__nr(cpus) && offset < priv_size; i++)
- cs_etm_get_metadata(cpus->map[i], &offset, itr, info);
- } else {
- /* get configuration for all CPUs in the system */
- for (i = 0; i < cpu__max_cpu(); i++)
+ for (i = 0; i < cpu__max_cpu() && offset < priv_size; i++)
+ if (cpu_map__has(cpu_map, i))
cs_etm_get_metadata(i, &offset, itr, info);
- }
+
+ cpu_map__put(online_cpus);

return 0;
}
--
2.7.4