From 86a976d1bd33f5105e77854c8291f4bb17ef1ebb Mon Sep 17 00:00:00 2001
From: Elliot Saba <sabae@valvesoftware.com>
Date: Fri, 8 Aug 2025 08:11:34 -0700
Subject: [PATCH] perfetto: Install and start `perfetto-traced.service`

This is so that we can have a long-running `traced` that applications
can connect to, even from boot.
---
 perfetto/perfetto-traced.service | 11 +++++++++++
 perfetto/perfetto.sh             | 32 ++++++++++++++++++++++++++------
 2 files changed, 37 insertions(+), 6 deletions(-)
 create mode 100644 perfetto/perfetto-traced.service

diff --git a/perfetto/perfetto-traced.service b/perfetto/perfetto-traced.service
new file mode 100644
index 0000000..ee678d5
--- /dev/null
+++ b/perfetto/perfetto-traced.service
@@ -0,0 +1,11 @@
+[Unit]
+Description=perfetto traced service
+
+[Service]
+Type=simple
+Restart=always
+ExecStart=/usr/bin/tracebox traced --set-socket-permissions=perf:0660:perf:0660
+
+[Install]
+WantedBy=multi-user.target
+
diff --git a/perfetto/perfetto.sh b/perfetto/perfetto.sh
index 42f0341..d60c485 100755
--- a/perfetto/perfetto.sh
+++ b/perfetto/perfetto.sh
@@ -21,19 +21,39 @@ if [[ -z "$(which tracebox)" ]]; then
     sudo pacman -Sy perfetto
 fi
 
+# Ensure traced service is running, warn if not
+if ! systemctl is-active perfetto-traced; then
+    echo "WARN: perfetto-traced service was not running, attempting to auto-install:" >&2
+    sudo ln -sv ${SCRIPT_DIR}/perfetto-traced.service /etc/systemd/system/perfetto-traced.service
+    sudo systemctl enable --now perfetto-traced
+    echo "NOTE: Workloads that were already started may not connect to perfetto correctly, you may need to restart them." >&2
+    echo "      The perfetto-traced service will automatically start upon boot, so this will persist through a reboot." >&2
+fi
+
 # Automatically timestamp the trace name
 TRACE_PATH="/tmp/perfetto-${CONFIG}-$(date '+%s').pftrace"
 
+CLEANUP_PIDS=()
+function cleanup()
+{
+    for PID in "${CLEANUP_PIDS[@]}"; do
+        kill "${PID}"
+    done
+}
+trap "cleanup" EXIT
+
 # Start pps-producer so that we get GPU events
 sudo pps-producer &
-PPS_PRODUCER_PID="$!"
-trap "kill -9 ${PPS_PRODUCER_PID}" EXIT
+CLEANUP_PIDS+=( "$!" )
 
-# Start tracebox in --system-sockets mode so pps-producer can connect
-sudo tracebox --system-sockets --txt -c "${SCRIPT_DIR}/configs/${CONFIG}" -o "${TRACE_PATH}"
-du -sh "${TRACE_PATH}"
+# Start traced_probes so we get all our system-level events (CPU scheduling, memory, etc....)
+sudo tracebox traced_probes &
+CLEANUP_PIDS+=( "$!" )
+
+sudo tracebox perfetto --txt -c "${SCRIPT_DIR}/configs/${CONFIG}" -o "${TRACE_PATH}"
 sudo chown "$(id -u):$(id -g)" "${TRACE_PATH}"
+du -sh "${TRACE_PATH}"
 
 # Cleanup
-kill -9 "${PPS_PRODUCER_PID}"
 trap "-" EXIT
+cleanup