From: Tom Zanussi <zanussi@kernel.org>
Date: Mon, 13 Apr 2026 22:35:38 +0000 (-0500)
Subject: selftests/ftrace: Add test case for fully-qualified variable references
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=621a59d8fc678762abc12ad8ad6bf616496fa4d2;p=thirdparty%2Fkernel%2Flinux.git

selftests/ftrace: Add test case for fully-qualified variable references

This test adds a variable (ts0) to two events (sched_waking and
sched_wakeup) and uses a fully-qualified variable reference to expicitly
choose a particular one (sched_wakeup.$ts0) when calculating the wakeup
latency.

Link: https://patch.msgid.link/ce9d96aeb84b2d40bd469fe9a346e225442873b1.1776112478.git.zanussi@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---

diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-fully-qualified-var-ref.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-fully-qualified-var-ref.tc
new file mode 100644
index 0000000000000..8d12cdd06f1d1
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-fully-qualified-var-ref.tc
@@ -0,0 +1,34 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: event trigger - test fully-qualified variable reference support
+# requires: set_event synthetic_events events/sched/sched_process_fork/hist ping:program
+
+fail() { #msg
+    echo $1
+    exit_fail
+}
+
+echo "Test fully-qualified variable reference support"
+
+echo 'wakeup_latency u64 lat; pid_t pid; int prio; char comm[16]' > synthetic_events
+echo 'hist:keys=comm:ts0=common_timestamp.usecs if comm=="ping"' > events/sched/sched_waking/trigger
+echo 'hist:keys=comm:ts0=common_timestamp.usecs if comm=="ping"' > events/sched/sched_wakeup/trigger
+echo 'hist:keys=next_comm:wakeup_lat=common_timestamp.usecs-sched.sched_wakeup.$ts0:onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,sched.sched_waking.prio,next_comm) if next_comm=="ping"' > events/sched/sched_switch/trigger
+echo 'hist:keys=pid,prio,comm:vals=lat:sort=pid,prio' > events/synthetic/wakeup_latency/trigger
+
+ping $LOCALHOST -c 3
+if ! grep -q "ping" events/synthetic/wakeup_latency/hist; then
+    fail "Failed to create inter-event histogram"
+fi
+
+if ! grep -q "synthetic_prio=prio" events/sched/sched_waking/hist; then
+    fail "Failed to create histogram with fully-qualified variable reference"
+fi
+
+echo '!hist:keys=next_comm:wakeup_lat=common_timestamp.usecs-sched.sched_wakeup.$ts0:onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,sched.sched_waking.prio,next_comm) if next_comm=="ping"' >> events/sched/sched_switch/trigger
+
+if grep -q "synthetic_prio=prio" events/sched/sched_waking/hist; then
+    fail "Failed to remove histogram with fully-qualified variable reference"
+fi
+
+exit 0