[PATCH v1 13/13] perf test uprobe_from_different_cu: Scope probe name to PID

[Ian Rogers]

The test builds a binary in a per-run temporary directory and probes
its foo function. The directory name is unique, but perf probe derives
the event name from the probed function and the group name from the
binary's basename, so every run registers the same probe_testfile:foo
event.

Running the test concurrently with itself, as 'perf test -r3' does,
therefore fails in all but one of the runs with:

  Error: event "foo" already exists.
   Hint: Remove existing event by 'perf probe -d'

and a losing run's cleanup goes on to delete the winning run's probe
out from under it.

Name the event after the pid, foo_$$, so that parallel runs no longer
collide. This lets the test stay in the parallel pass rather than
having to be marked (exclusive).

Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
 .../perf/tests/shell/test_uprobe_from_different_cu.sh | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/tools/perf/tests/shell/test_uprobe_from_different_cu.sh b/tools/perf/tests/shell/test_uprobe_from_different_cu.sh
index 7adf9755d6de..47c99d93436b 100755
--- a/tools/perf/tests/shell/test_uprobe_from_different_cu.sh
+++ b/tools/perf/tests/shell/test_uprobe_from_different_cu.sh
@@ -18,12 +18,19 @@ fi
 
 temp_dir=$(mktemp -d /tmp/perf-uprobe-different-cu-sh.XXXXXXXXXX)
 
+# The name of the uprobe added and removed below. The probe is placed on
+# ${temp_dir}/testfile, but perf probe derives the event name from the probed
+# function and the group name from the binary's basename, so every run would
+# otherwise share one probe_testfile:foo event, and a concurrent run would
+# fail with 'event "foo" already exists'. Scope the event name to the pid.
+probe_name="foo_$$"
+
 cleanup()
 {
 	trap - EXIT TERM INT
 	if [[ "${temp_dir}" =~ ^/tmp/perf-uprobe-different-cu-sh.*$ ]]; then
 		echo "--- Cleaning up ---"
-		perf probe -x ${temp_dir}/testfile -d foo || true
+		perf probe -x ${temp_dir}/testfile -d ${probe_name} || true
 		rm -f "${temp_dir}/"*
 		rmdir "${temp_dir}"
 	fi
@@ -84,6 +91,6 @@ gcc -g -Og -c ${temp_dir}/testfile-main.c -o ${temp_dir}/testfile-main.o
 gcc -g -Og -o ${temp_dir}/testfile ${temp_dir}/testfile-foo.o ${temp_dir}/testfile-main.o
 
 perf probe -x ${temp_dir}/testfile --funcs foo | grep "foo"
-perf probe -x ${temp_dir}/testfile foo
+perf probe -x ${temp_dir}/testfile ${probe_name}=foo
 
 cleanup
-- 
2.55.0.1082.g2b9226bbc0-goog