rtla/timerlat_hist: Abort event processing on second signal

If either SIGINT is received twice, or after a SIGALRM (that is, after
timerlat was supposed to stop), abort processing events currently left
in the tracefs buffer and exit immediately.

This allows the user to exit rtla without waiting for processing all
events, should that take longer than wanted, at the cost of not
processing all samples.

Cc: John Kacur <jkacur@redhat.com>
Cc: Luis Goncalves <lgoncalv@redhat.com>
Cc: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/20250116144931.649593-5-tglozar@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index f1edf1c8a7b071f081a92b9f305a5cd1f6c91c65..53ded187b33a30353b88db2913e36b4ca08e3d58 100644 (file)
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -1134,6 +1134,14 @@ static int stop_tracing;
 static struct trace_instance *hist_inst = NULL;
 static void stop_hist(int sig)
 {
+       if (stop_tracing) {
+               /*
+                * Stop requested twice in a row; abort event processing and
+                * exit immediately
+                */
+               tracefs_iterate_stop(hist_inst->inst);
+               return;
+       }
        stop_tracing = 1;
        if (hist_inst)
                trace_instance_stop(hist_inst);