rtla/timerlat_top: Abort event processing on second signal

[ Upstream commit 80967b354a76b360943af384c10d807d98bea5c4 ]

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/20250116144931.649593-6-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_top.c b/tools/tracing/rtla/src/timerlat_top.c
index 08e940ecdc966e9247d3f9413946e976c4ddc8be..46c3405a356f5e0c5a99f3d8d4d69ae495c4feb3 100644 (file)
--- a/tools/tracing/rtla/src/timerlat_top.c
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -578,6 +578,14 @@ static int stop_tracing;
 static struct trace_instance *top_inst = NULL;
 static void stop_top(int sig)
 {
+       if (stop_tracing) {
+               /*
+                * Stop requested twice in a row; abort event processing and
+                * exit immediately
+                */
+               tracefs_iterate_stop(top_inst->inst);
+               return;
+       }
        stop_tracing = 1;
        if (top_inst)
                trace_instance_stop(top_inst);