On Tue, Mar 08, 2022 at 08:49:56PM +0000, Mike Leach wrote:
Adds in notifier calls to the trace ID allocator that perf events are starting and stopping.
This ensures that Trace IDs associated with CPUs remain the same throughout the perf session, and are only release when all perf sessions are complete.
Signed-off-by: Mike Leach mike.leach@linaro.org
drivers/hwtracing/coresight/coresight-etm-perf.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index c039b6ae206f..008f9dac429d 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -22,6 +22,7 @@ #include "coresight-etm-perf.h" #include "coresight-priv.h" #include "coresight-syscfg.h" +#include "coresight-trace-id.h" static struct pmu etm_pmu; static bool etm_perf_up; @@ -223,11 +224,21 @@ static void free_event_data(struct work_struct *work) struct list_head **ppath; ppath = etm_event_cpu_path_ptr(event_data, cpu);
if (!(IS_ERR_OR_NULL(*ppath)))
if (!(IS_ERR_OR_NULL(*ppath))) { coresight_release_path(*ppath);/** perf may have read a trace id for a cpu, but never actually* executed code on that cpu - which means the trace id would* not release on disable. Re-release here to be sure.*/coresight_trace_id_put_cpu_id(cpu, coresight_get_trace_id_map());
A CPU gets a traceID in event_etm_start() when the event is installed for running. Do you see a scenario where etm_free_aux() is called without previously calling event_etm_stop()?
}
- /* mark perf event as done for trace id allocator */
- coresight_trace_id_perf_stop();
- free_percpu(event_data->path); kfree(event_data);
} @@ -314,6 +325,9 @@ static void *etm_setup_aux(struct perf_event *event, void **pages, sink = user_sink = coresight_get_sink_by_id(id); }
- /* tell the trace ID allocator that a perf event is starting up */
- coresight_trace_id_perf_start();
- /* check if user wants a coresight configuration selected */ cfg_hash = (u32)((event->attr.config2 & GENMASK_ULL(63, 32)) >> 32); if (cfg_hash) {
-- 2.17.1