initrdscripts: add bootchart hook w/ OS_DEVELOPMENT=1

Run systemd-bootchart in an initramfs hook early in the boot process to collect information on CPU and disk load, and output to a chart in /run/log. This hook is disabled by default, and can be enabled using the `bootchart` bootparam. Change-type: patch Signed-off-by: Joseph Kogut <[email protected]>
balena-os · Dec 5, 2024 · 29ac5ae · 29ac5ae
1 parent f7006b8
commit 29ac5ae
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diff --git a/meta-balena-common/recipes-core/images/balena-image-initramfs.bb b/meta-balena-common/recipes-core/images/balena-image-initramfs.bb
@@ -30,6 +30,8 @@ PACKAGE_INSTALL:append = " initramfs-module-console-null-workaround"
 PACKAGE_INSTALL:append = "${@oe.utils.conditional('SIGN_API','','',' initramfs-module-cryptsetup initramfs-module-kexec',d)}"
 PACKAGE_INSTALL:append = "${@oe.utils.conditional('PARTITION_TABLE_TYPE','gpt',' gptfdisk ','',d)}"
 
+PACKAGE_INSTALL:append = "${@bb.utils.contains('DISTRO_FEATURES', 'osdev-image', ' initramfs-module-bootchart', '', d)}"
+
 # Do not pollute the initrd image with rootfs features
 IMAGE_FEATURES = ""
 

diff --git a/meta-balena-common/recipes-core/initrdscripts/files/bootchart b/meta-balena-common/recipes-core/initrdscripts/files/bootchart
@@ -0,0 +1,19 @@
+#!/bin/sh
+
+bootchart_enabled() {
+	# shellcheck disable=SC2154
+	[ "${bootparam_bootchart}" = "true" ] && return 0 || return 1
+}
+
+bootchart_run() {
+	# bootchart runs backgrounded through switch_root, after the real root
+	# is mounted and init is run, until it's collected enough samples, at
+	# which point it exits
+	#
+	# argv[0][0] is replaced with '@' in main() to indicate that the
+	# process remains from the initramfs, and to prevent init from killing
+	# it
+	#
+	# https://freedesktop.org/wiki/Software/systemd/RootStorageDaemons/
+	( exec /lib/systemd/systemd-bootchart ) &
+}
diff --git a/meta-balena-common/recipes-core/initrdscripts/initramfs-framework_%.bbappend b/meta-balena-common/recipes-core/initrdscripts/initramfs-framework_%.bbappend
@@ -3,6 +3,7 @@ FILESEXTRAPATHS:prepend := "${THISDIR}/files:"
 SRC_URI:append = " \
     file://console_null_workaround \
     file://prepare \
+    file://bootchart \
     file://fsck \
     file://fsuuidsinit \
     file://machineid \
@@ -22,6 +23,7 @@ SRC_URI:append = " \
 do_install:append() {
     install -m 0755 ${WORKDIR}/console_null_workaround ${D}/init.d/000-console_null_workaround
     install -m 0755 ${WORKDIR}/prepare ${D}/init.d/00-prepare
+    install -m 0755 ${WORKDIR}/bootchart ${D}/init.d/000-bootchart
     install -m 0755 ${WORKDIR}/fsuuidsinit ${D}/init.d/75-fsuuidsinit
     install -m 0755 ${WORKDIR}/fsck ${D}/init.d/87-fsck
     install -m 0755 ${WORKDIR}/rootfs ${D}/init.d/90-rootfs
@@ -48,6 +50,7 @@ do_install:append() {
 
 PACKAGES:append = " \
     initramfs-module-console-null-workaround \
+    initramfs-module-bootchart \
     initramfs-module-fsck \
     initramfs-module-machineid \
     initramfs-module-resindataexpander \
@@ -68,6 +71,10 @@ SUMMARY:initramfs-module-console-null-workaround = "Workaround needed for when c
 RDEPENDS:initramfs-module-console-null-workaround = "${PN}-base"
 FILES:initramfs-module-console-null-workaround = "/init.d/000-console_null_workaround"
 
+SUMMARY:initramfs-module-bootchart = "Boot profiling"
+RDEPENDS:initramfs-module-bootchart = "${PN}-base systemd-bootchart"
+FILES:initramfs-module-bootchart = "/init.d/000-bootchart"
+
 SUMMARY:initramfs-module-fsck = "Filesystem check for partitions"
 RDEPENDS:initramfs-module-fsck = "${PN}-base e2fsprogs-e2fsck dosfstools-fsck"
 FILES:initramfs-module-fsck = "/init.d/87-fsck"