rtla/timerlat_hist: Abort event processing on second signal

[ Upstream commit d6899e560366e10141189697502bc5521940c588 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index 83cc7ef3d36b3077b4e8e73a2008a2a8a1b0f68d..b7a7dcd68b570b347b006e2e58f8eb9e557c0f3c 100644 (file)
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -786,6 +786,14 @@ 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);