From 898f594a944269e121bc64cf77abad367674591e Mon Sep 17 00:00:00 2001
From: Jonathan Siegel <248302+usiegj00@users.noreply.github.com>
Date: Tue, 15 Oct 2024 07:12:52 +0900
Subject: [PATCH] Add cgroupsv2 support

---
 support/build/php | 33 +++++++++++++++++++++++++++------
 1 file changed, 27 insertions(+), 6 deletions(-)

diff --git a/support/build/php b/support/build/php
index 190150525..b85acefe6 100755
--- a/support/build/php
+++ b/support/build/php
@@ -188,22 +188,43 @@ EOF
 cat > ${OUT_PREFIX}/bin/profile.php.sh <<'EOF'
 export PATH="$HOME/.heroku/php/bin:$HOME/.heroku/php/sbin:$PATH"
 
-# read memory limit of dyno
-mlib="/sys/fs/cgroup/memory/memory.limit_in_bytes"
+# Check for memory limit in cgroupsv1 or cgroupsv2
+# cgroupsv1 memory limit file
+mlib_v1="/sys/fs/cgroup/memory/memory.limit_in_bytes"
+# cgroupsv2 memory limit file
+mlib_v2="/sys/fs/cgroup/memory.max"
+
 # get php.ini location; don't forget to suppress INI scan dir to prevent e.g. New Relic from starting
 php_ini_path=$(PHP_INI_SCAN_DIR= php -r 'echo get_cfg_var("cfg_file_path");')
-if [[ -f "$mlib" && -n "$php_ini_path" ]]; then
+
+# Check if php.ini path exists and cgroups memory limit file is present
+if [[ -n "$php_ini_path" ]]; then
 	php_cli_ini_path=$(dirname "$php_ini_path")/php-cli.ini
 	# create php-cli.ini from php.ini unless it exists
 	# we can't cp -n instead because php_ini_path would already be php-cli.ini and that would error
 	if [[ "$php_ini_path" != "$php_cli_ini_path" ]]; then
 		cp "$php_ini_path" "$php_cli_ini_path"
 	fi
-	# compute memory limit, up to 16 GB
+
+	# Default maximum memory limit of 16 GB
 	max_memory_limit=$(( 16 * 1024 * 1024 * 1024 ))
-	sys_memory_limit=$(cat "$mlib")
+
+	# Determine which cgroup version to use for memory limit
+	if [[ -f "$mlib_v1" ]]; then
+		# cgroupsv1: read memory limit from memory.limit_in_bytes
+		sys_memory_limit=$(cat "$mlib_v1")
+	elif [[ -f "$mlib_v2" && "$(cat "$mlib_v2")" != "max" ]]; then
+		# cgroupsv2: read memory limit from memory.max, skip if "max" (no limit)
+		sys_memory_limit=$(cat "$mlib_v2")
+	else
+		# Fallback if no memory limit is found
+		sys_memory_limit=$max_memory_limit
+	fi
+
+	# Ensure memory limit doesn't exceed 16 GB
 	memory_limit=$(( sys_memory_limit > max_memory_limit ? max_memory_limit : sys_memory_limit ))
-	# append to php-cli.ini
+
+	# Append memory limit to php-cli.ini
 	echo $'\n;inserted by ~/.profile.d/ script' >> "$php_cli_ini_path"
 	echo "memory_limit=$memory_limit" >> "$php_cli_ini_path"
 fi