Enhance boot performance by adjusting service dependencies and loading quirks in parallel

2026-07-12 18:19:42 -07:00 · 2026-05-11 19:29:07 -03:00
parent 424a286755
commit d230c4243e
5 changed files with 66 additions and 33 deletions
@@ -1,7 +1,9 @@
 [Unit]
 Description=ArchR Memory Manager
-After=local-fs.target
-DefaultDependencies=no
+# Run AFTER /storage is mountable so we can read /storage/.config/swap.conf
+# for user overrides. RequiresMountsFor pulls in the mount automatically.
+After=local-fs.target archr-automount.service
+RequiresMountsFor=/storage
 Conflicts=shutdown.target
 Before=shutdown.target

@@ -14,4 +16,9 @@ ExecStop=/usr/bin/archr-memory-manager --stop
 RemainAfterExit=yes

 [Install]
-WantedBy=basic.target
+# Was WantedBy=basic.target, which put the ~3.9s modprobe zram + udev wait
+# + sysctl tuning loop on the critical path before sockets.target →
+# sysinit.target. Moving to multi-user.target keeps swap+KSM+VM tuning
+# functional (it still happens before EmulationStation starts) but
+# unblocks sysinit/basic for the rest of the boot.
+WantedBy=multi-user.target
@@ -50,36 +50,29 @@ if [ -d /sys/class/pwm/pwmchip0 ]; then
  echo 0 > /sys/class/pwm/pwmchip0/pwm0/enable 2>/dev/null
 fi

-### Load platform specific quirks
-if [ -d "/usr/lib/autostart/quirks/platforms/${HW_DEVICE}" ]
-then
-  log "Run ${HW_DEVICE} quirks."
-  tocon "Applying ${HW_DEVICE} quirks..."
-  for script in "/usr/lib/autostart/quirks/platforms/${HW_DEVICE}"/*
-  do
-    log "Run ${script}"
-    trace_step "platform-quirk:${script}"
-    if [ -f "${script}" ]
-    then
-      "${script}" 2>&1 >>${BOOTLOG}
-    fi
-  done
-fi
+### Load platform + device quirks in parallel. Every quirk writes to its
+### own /storage/.config/profile.d/NNN-name file or to a hardware sysfs
+### path — they don't share state, so running them concurrently is safe
+### and trims several seconds off boot (most quirks are sub-second cats).
+### Each quirk is logged with its end-tag so a failure is still
+### attributable in /var/log/boot.log; the trace_step marker for slow
+### debugging picks the LAST-launched script (good enough — if a quirk
+### hangs we want to know what's still running, not the entry order).
+QUIRK_DIRS=""
+[ -d "/usr/lib/autostart/quirks/platforms/${HW_DEVICE}" ] && QUIRK_DIRS+=" /usr/lib/autostart/quirks/platforms/${HW_DEVICE}"
+[ -d "/usr/lib/autostart/quirks/devices/${QUIRK_DEVICE}"  ] && QUIRK_DIRS+=" /usr/lib/autostart/quirks/devices/${QUIRK_DEVICE}"

-### Load device specific quirks
-if [ -d "/usr/lib/autostart/quirks/devices/${QUIRK_DEVICE}" ]
-then
-  log "Run ${QUIRK_DEVICE} quirks."
-  tocon "Applying ${QUIRK_DEVICE} quirks..."
-  for script in "/usr/lib/autostart/quirks/devices/${QUIRK_DEVICE}"/*
-  do
-    log "Run ${script}"
-    trace_step "device-quirk:${script}"
-    if [ -f "${script}" ]
-    then
-      "${script}" 2>&1 >>${BOOTLOG}
-    fi
+if [ -n "${QUIRK_DIRS}" ]; then
+  tocon "Applying ${HW_DEVICE} / ${QUIRK_DEVICE} quirks..."
+  for QDIR in ${QUIRK_DIRS}; do
+    for script in "${QDIR}"/*; do
+      [ -f "${script}" ] || continue
+      log "Run ${script}"
+      trace_step "quirk:${script}"
+      ( "${script}" 2>&1 >>${BOOTLOG}; log "Done ${script}" ) &
+    done
  done
+  wait
 fi

 ### Start the automount service
@@ -154,8 +154,15 @@ post_makeinstall_target() {

  safe_remove ${INSTALL}/usr/lib/systemd/system/systemd-journald-audit.socket

-  # adjust systemd-hwdb-update (we have read-only /etc).
-  sed '/^ConditionNeedsUpdate=.*$/d' -i ${INSTALL}/usr/lib/systemd/system/systemd-hwdb-update.service
+  # Pre-build hwdb.bin at image creation so systemd-hwdb-update.service
+  # doesn't have to rebuild it on every boot (was costing ~4.4s in
+  # systemd-analyze blame). The file format is arch-independent so the
+  # host's systemd-hwdb is safe to use. The override.conf in
+  # system.d/systemd-hwdb-update.service.d makes the service a no-op at
+  # runtime; this step ensures the binary db is present for udev.
+  if command -v systemd-hwdb >/dev/null; then
+    systemd-hwdb --usr --root=${INSTALL} update || true
+  fi

  # remove nspawn
  safe_remove ${INSTALL}/usr/bin/systemd-nspawn
@@ -0,0 +1,16 @@
+[Unit]
+# /usr is read-only squashfs/ext2 in ArchR — the hwdb source files never
+# change between boots, so rebuilding hwdb.bin at every boot was costing
+# ~4s on RK3326 (systemd-analyze blame: 4.417s) and showed up in the
+# critical chain via sysinit.target.
+#
+# We rebuild hwdb.bin at image creation (see systemd post_makeinstall) and
+# ship it with the image. At runtime, skip the rebuild unconditionally by
+# ConditionPathExists pointing at a sentinel path that never exists.
+ConditionPathExists=/run/systemd/never-create-this
+
+[Service]
+# Defensive: if the condition somehow doesn't kick in, exit immediately
+# so we still avoid the 4s rebuild.
+ExecStart=
+ExecStart=/bin/true
@@ -1,3 +1,13 @@
+[Unit]
+# systemd-resolved was sitting in the boot critical chain via
+# nss-lookup.target → basic.target → sysinit.target, costing ~4.3s in
+# blame. None of ArchR's boot-critical services actually need DNS
+# (EmulationStation, sway, automount). Drop the implicit pull so
+# resolved starts in the background while the UI comes up; DNS is ready
+# by the time the user actually opens a network app.
+Wants=
+Before=systemd-user-sessions.service shutdown.target
+
 [Service]
 # Relax sandboxing to prevent race conditions on boot with OverlayFS
 # Fixes error: NAMESPACE "Failed to set up mount namespacing" which can occur based on overlayfs setup speed