On 21/08/2026 10:50, James Clark wrote:
Don't set the aux_hwid_done bit when writes fail so that it can be retried later if the ring buffer was full.
Add a second attempt on stop in case this session only has one call to start. Otherwise there is no chance to retry and it isn't fixed by not setting aux_hwid_done.
Signed-off-by: James Clark james.clark@linaro.org
drivers/hwtracing/coresight/coresight-etm-perf.c | 52 +++++++++++++++--------- 1 file changed, 32 insertions(+), 20 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index 09b21a711a87..0ffc5cd9c88f 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -536,6 +536,31 @@ static int etm_event_resume(struct coresight_path *path) return ret; } +static void etm_output_hw_id(struct perf_event *event,
struct etm_event_data *event_data,struct coresight_path *path,struct coresight_device *sink)+{
- int cpu = smp_processor_id();
- u64 hw_id;
- /*
* output cpu / trace ID in perf record, once for the lifetime* of the event.*/- if (!cpumask_test_cpu(cpu, &event_data->aux_hwid_done)) {
hw_id = FIELD_PREP(CS_AUX_HW_ID_MAJOR_VERSION_MASK,CS_AUX_HW_ID_MAJOR_VERSION);hw_id |= FIELD_PREP(CS_AUX_HW_ID_MINOR_VERSION_MASK,CS_AUX_HW_ID_MINOR_VERSION);hw_id |= FIELD_PREP(CS_AUX_HW_ID_TRACE_ID_MASK, path->trace_id);hw_id |= FIELD_PREP(CS_AUX_HW_ID_SINK_ID_MASK, coresight_get_sink_id(sink));if (!perf_report_aux_output_id(event, hw_id))cpumask_set_cpu(cpu, &event_data->aux_hwid_done);- }
+}
- static void etm_event_start(struct perf_event *event, int flags) { int cpu = smp_processor_id();
@@ -544,7 +569,6 @@ static void etm_event_start(struct perf_event *event, int flags) struct perf_output_handle *handle = &ctxt->handle; struct coresight_device *source, *sink; struct coresight_path *path;
- u64 hw_id;
if (flags & PERF_EF_RESUME) { path = etm_event_get_ctxt_path(ctxt); @@ -596,22 +620,7 @@ static void etm_event_start(struct perf_event *event, int flags) if (coresight_enable_source(source, event, CS_MODE_PERF, path)) goto fail_disable_path;
- /*
* output cpu / trace ID in perf record, once for the lifetime* of the event.*/- if (!cpumask_test_cpu(cpu, &event_data->aux_hwid_done)) {
cpumask_set_cpu(cpu, &event_data->aux_hwid_done);hw_id = FIELD_PREP(CS_AUX_HW_ID_MAJOR_VERSION_MASK,CS_AUX_HW_ID_MAJOR_VERSION);hw_id |= FIELD_PREP(CS_AUX_HW_ID_MINOR_VERSION_MASK,CS_AUX_HW_ID_MINOR_VERSION);hw_id |= FIELD_PREP(CS_AUX_HW_ID_TRACE_ID_MASK, path->trace_id);hw_id |= FIELD_PREP(CS_AUX_HW_ID_SINK_ID_MASK, coresight_get_sink_id(sink));perf_report_aux_output_id(event, hw_id);- }
- etm_output_hw_id(event, event_data, path, sink);
out: /* Tell the perf core the event is alive */ @@ -630,7 +639,7 @@ static void etm_event_start(struct perf_event *event, int flags) */ if (READ_ONCE(handle->event)) { perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
perf_aux_output_end(handle, 0);
perf_aux_output_end(path->handle, 0);
Accidentally left this in from hacking. It doesn't do anything so I'll remove it.