diff --git a/libprocessgroup/Android.bp b/libprocessgroup/Android.bp
index a60bfe9..d623a11 100644
--- a/libprocessgroup/Android.bp
+++ b/libprocessgroup/Android.bp
@@ -17,7 +17,7 @@
 
 libprocessgroup_flag_aware_cc_defaults {
     name: "libprocessgroup_build_flags_cc",
-    cpp_std: "gnu++20",
+    cpp_std: "gnu++23",
     soong_config_variables: {
         memcg_v2_force_enabled: {
             cflags: [
@@ -116,5 +116,6 @@
     ],
     static_libs: [
         "libgmock",
+        "libprocessgroup_util",
     ],
 }
diff --git a/libprocessgroup/cgroup_map.cpp b/libprocessgroup/cgroup_map.cpp
index fb01cfd..aeccfe8 100644
--- a/libprocessgroup/cgroup_map.cpp
+++ b/libprocessgroup/cgroup_map.cpp
@@ -151,7 +151,7 @@
 void CgroupMap::Print() const {
     if (!loaded_) {
         LOG(ERROR) << "CgroupMap::Print called for [" << getpid()
-                   << "] failed, RC file was not initialized properly";
+                   << "] failed, cgroups were not initialized properly";
         return;
     }
     LOG(INFO) << "File version = " << ACgroupFile_getVersion();
@@ -221,7 +221,7 @@
             if (__builtin_available(android 36, *)) {
                 max_activation_depth = ACgroupController_getMaxActivationDepth(controller);
             }
-            const int depth = util::GetCgroupDepth(ACgroupController_getPath(controller), path);
+            const int depth = GetCgroupDepth(ACgroupController_getPath(controller), path);
 
             if (flags & CGROUPRC_CONTROLLER_FLAG_NEEDS_ACTIVATION && depth < max_activation_depth) {
                 std::string str("+");
diff --git a/libprocessgroup/cgrouprc/Android.bp b/libprocessgroup/cgrouprc/Android.bp
index cb91247..38b2fa3 100644
--- a/libprocessgroup/cgrouprc/Android.bp
+++ b/libprocessgroup/cgrouprc/Android.bp
@@ -49,7 +49,8 @@
         "libbase",
     ],
     static_libs: [
-        "libcgrouprc_format",
+        "libjsoncpp",
+        "libprocessgroup_util",
     ],
     stubs: {
         symbol_file: "libcgrouprc.map.txt",
diff --git a/libprocessgroup/cgrouprc/a_cgroup_file.cpp b/libprocessgroup/cgrouprc/a_cgroup_file.cpp
index e26d841..33c8376 100644
--- a/libprocessgroup/cgrouprc/a_cgroup_file.cpp
+++ b/libprocessgroup/cgrouprc/a_cgroup_file.cpp
@@ -14,93 +14,51 @@
  * limitations under the License.
  */
 
-#include <sys/mman.h>
-#include <sys/stat.h>
-
-#include <memory>
+#include <iterator>
 
 #include <android-base/logging.h>
-#include <android-base/stringprintf.h>
-#include <android-base/unique_fd.h>
 #include <android/cgrouprc.h>
-#include <processgroup/processgroup.h>
+#include <processgroup/util.h>
 
 #include "cgrouprc_internal.h"
 
-using android::base::StringPrintf;
-using android::base::unique_fd;
-
-using android::cgrouprc::format::CgroupController;
-using android::cgrouprc::format::CgroupFile;
-
-static CgroupFile* LoadRcFile() {
-    struct stat sb;
-
-    unique_fd fd(TEMP_FAILURE_RETRY(open(CGROUPS_RC_PATH, O_RDONLY | O_CLOEXEC)));
-    if (fd < 0) {
-        PLOG(ERROR) << "open() failed for " << CGROUPS_RC_PATH;
+static CgroupDescriptorMap* LoadDescriptors() {
+    CgroupDescriptorMap* descriptors = new CgroupDescriptorMap;
+    if (!ReadDescriptors(descriptors)) {
+        LOG(ERROR) << "Failed to load cgroup description file";
         return nullptr;
     }
-
-    if (fstat(fd, &sb) < 0) {
-        PLOG(ERROR) << "fstat() failed for " << CGROUPS_RC_PATH;
-        return nullptr;
-    }
-
-    size_t file_size = sb.st_size;
-    if (file_size < sizeof(CgroupFile)) {
-        LOG(ERROR) << "Invalid file format " << CGROUPS_RC_PATH;
-        return nullptr;
-    }
-
-    CgroupFile* file_data = (CgroupFile*)mmap(nullptr, file_size, PROT_READ, MAP_SHARED, fd, 0);
-    if (file_data == MAP_FAILED) {
-        PLOG(ERROR) << "Failed to mmap " << CGROUPS_RC_PATH;
-        return nullptr;
-    }
-
-    if (file_data->version_ != CgroupFile::FILE_CURR_VERSION) {
-        LOG(ERROR) << CGROUPS_RC_PATH << " file version mismatch";
-        munmap(file_data, file_size);
-        return nullptr;
-    }
-
-    auto expected = sizeof(CgroupFile) + file_data->controller_count_ * sizeof(CgroupController);
-    if (file_size != expected) {
-        LOG(ERROR) << CGROUPS_RC_PATH << " file has invalid size, expected " << expected
-                   << ", actual " << file_size;
-        munmap(file_data, file_size);
-        return nullptr;
-    }
-
-    return file_data;
+    return descriptors;
 }
 
-static CgroupFile* GetInstance() {
+static const CgroupDescriptorMap* GetInstance() {
     // Deliberately leak this object (not munmap) to avoid a race between destruction on
     // process exit and concurrent access from another thread.
-    static auto* file = LoadRcFile();
-    return file;
+    static const CgroupDescriptorMap* descriptors = LoadDescriptors();
+    return descriptors;
 }
 
 uint32_t ACgroupFile_getVersion() {
-    auto file = GetInstance();
-    if (file == nullptr) return 0;
-    return file->version_;
+    static constexpr uint32_t FILE_VERSION_1 = 1;
+    auto descriptors = GetInstance();
+    if (descriptors == nullptr) return 0;
+    // There has only ever been one version, and there will be no more since cgroup.rc is no more
+    return FILE_VERSION_1;
 }
 
 uint32_t ACgroupFile_getControllerCount() {
-    auto file = GetInstance();
-    if (file == nullptr) return 0;
-    return file->controller_count_;
+    auto descriptors = GetInstance();
+    if (descriptors == nullptr) return 0;
+    return descriptors->size();
 }
 
 const ACgroupController* ACgroupFile_getController(uint32_t index) {
-    auto file = GetInstance();
-    if (file == nullptr) return nullptr;
-    CHECK(index < file->controller_count_);
+    auto descriptors = GetInstance();
+    if (descriptors == nullptr) return nullptr;
+    CHECK(index < descriptors->size());
     // Although the object is not actually an ACgroupController object, all ACgroupController_*
     // functions implicitly convert ACgroupController* back to CgroupController* before invoking
     // member functions.
-    return static_cast<ACgroupController*>(&file->controllers_[index]);
+    const CgroupController* p = std::next(descriptors->begin(), index)->second.controller();
+    return static_cast<const ACgroupController*>(p);
 }
diff --git a/libprocessgroup/cgrouprc/cgrouprc_internal.h b/libprocessgroup/cgrouprc/cgrouprc_internal.h
index cd02f03..d517703 100644
--- a/libprocessgroup/cgrouprc/cgrouprc_internal.h
+++ b/libprocessgroup/cgrouprc/cgrouprc_internal.h
@@ -16,9 +16,6 @@
 
 #pragma once
 
-#include <android/cgrouprc.h>
+#include <processgroup/cgroup_controller.h>
 
-#include <processgroup/format/cgroup_controller.h>
-#include <processgroup/format/cgroup_file.h>
-
-struct ACgroupController : android::cgrouprc::format::CgroupController {};
+struct ACgroupController : CgroupController {};
diff --git a/libprocessgroup/cgrouprc_format/Android.bp b/libprocessgroup/cgrouprc_format/Android.bp
index 0590924..6f9ab3e 100644
--- a/libprocessgroup/cgrouprc_format/Android.bp
+++ b/libprocessgroup/cgrouprc_format/Android.bp
@@ -23,17 +23,4 @@
     vendor_ramdisk_available: true,
     recovery_available: true,
     native_bridge_supported: true,
-    srcs: [
-        "cgroup_controller.cpp",
-    ],
-    cflags: [
-        "-Wall",
-        "-Werror",
-    ],
-    export_include_dirs: [
-        "include",
-    ],
-    shared_libs: [
-        "libbase",
-    ],
 }
diff --git a/libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_file.h b/libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_file.h
deleted file mode 100644
index 2d9786f..0000000
--- a/libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_file.h
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- * Copyright (C) 2019 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#pragma once
-
-#include <cstdint>
-
-#include <processgroup/format/cgroup_controller.h>
-
-namespace android {
-namespace cgrouprc {
-namespace format {
-
-struct CgroupFile {
-    uint32_t version_;
-    uint32_t controller_count_;
-    CgroupController controllers_[];
-
-    static constexpr uint32_t FILE_VERSION_1 = 1;
-    static constexpr uint32_t FILE_CURR_VERSION = FILE_VERSION_1;
-};
-
-}  // namespace format
-}  // namespace cgrouprc
-}  // namespace android
diff --git a/libprocessgroup/include/processgroup/processgroup.h b/libprocessgroup/include/processgroup/processgroup.h
index ffffeb4..8057757 100644
--- a/libprocessgroup/include/processgroup/processgroup.h
+++ b/libprocessgroup/include/processgroup/processgroup.h
@@ -57,7 +57,7 @@
 
 bool SetProcessProfilesCached(uid_t uid, pid_t pid, const std::vector<std::string>& profiles);
 
-static constexpr const char* CGROUPS_RC_PATH = "/dev/cgroup_info/cgroup.rc";
+[[deprecated]] static constexpr const char* CGROUPS_RC_PATH = "/dev/cgroup_info/cgroup.rc";
 
 bool UsePerAppMemcg();
 
diff --git a/libprocessgroup/internal.h b/libprocessgroup/internal.h
new file mode 100644
index 0000000..ef85579
--- /dev/null
+++ b/libprocessgroup/internal.h
@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <string>
+
+static const std::string CGROUP_V2_ROOT_DEFAULT = "/sys/fs/cgroup";
\ No newline at end of file
diff --git a/libprocessgroup/setup/Android.bp b/libprocessgroup/setup/Android.bp
index 1a4ad01..cc6c67c 100644
--- a/libprocessgroup/setup/Android.bp
+++ b/libprocessgroup/setup/Android.bp
@@ -33,7 +33,6 @@
         "libjsoncpp",
     ],
     static_libs: [
-        "libcgrouprc_format",
         "libprocessgroup_util",
     ],
     header_libs: [
diff --git a/libprocessgroup/setup/cgroup_descriptor.h b/libprocessgroup/setup/cgroup_descriptor.h
index 06ce186..1afd2ee 100644
--- a/libprocessgroup/setup/cgroup_descriptor.h
+++ b/libprocessgroup/setup/cgroup_descriptor.h
@@ -21,10 +21,7 @@
 
 #include <sys/stat.h>
 
-#include <processgroup/format/cgroup_controller.h>
-
-namespace android {
-namespace cgrouprc {
+#include <processgroup/cgroup_controller.h>
 
 // Complete controller description for mounting cgroups
 class CgroupDescriptor {
@@ -33,7 +30,7 @@
                      mode_t mode, const std::string& uid, const std::string& gid, uint32_t flags,
                      uint32_t max_activation_depth);
 
-    const format::CgroupController* controller() const { return &controller_; }
+    const CgroupController* controller() const { return &controller_; }
     mode_t mode() const { return mode_; }
     std::string uid() const { return uid_; }
     std::string gid() const { return gid_; }
@@ -41,11 +38,8 @@
     void set_mounted(bool mounted);
 
   private:
-    format::CgroupController controller_;
+    CgroupController controller_;
     mode_t mode_ = 0;
     std::string uid_;
     std::string gid_;
 };
-
-}  // namespace cgrouprc
-}  // namespace android
diff --git a/libprocessgroup/setup/cgroup_map_write.cpp b/libprocessgroup/setup/cgroup_map_write.cpp
index bd41874..8211680 100644
--- a/libprocessgroup/setup/cgroup_map_write.cpp
+++ b/libprocessgroup/setup/cgroup_map_write.cpp
@@ -22,45 +22,28 @@
 #include <fcntl.h>
 #include <grp.h>
 #include <pwd.h>
-#include <sys/mman.h>
 #include <sys/mount.h>
 #include <sys/stat.h>
 #include <sys/types.h>
-#include <time.h>
 #include <unistd.h>
 
 #include <optional>
 
 #include <android-base/file.h>
 #include <android-base/logging.h>
-#include <android-base/properties.h>
-#include <android-base/stringprintf.h>
-#include <android-base/unique_fd.h>
-#include <android/cgrouprc.h>
-#include <json/reader.h>
-#include <json/value.h>
-#include <processgroup/format/cgroup_file.h>
+#include <processgroup/cgroup_descriptor.h>
 #include <processgroup/processgroup.h>
 #include <processgroup/setup.h>
 #include <processgroup/util.h>
 
 #include "../build_flags.h"
-#include "cgroup_descriptor.h"
-
-using android::base::GetUintProperty;
-using android::base::StringPrintf;
-using android::base::unique_fd;
-
-namespace android {
-namespace cgrouprc {
+#include "../internal.h"
 
 static constexpr const char* CGROUPS_DESC_FILE = "/etc/cgroups.json";
 static constexpr const char* CGROUPS_DESC_VENDOR_FILE = "/vendor/etc/cgroups.json";
 
 static constexpr const char* TEMPLATE_CGROUPS_DESC_API_FILE = "/etc/task_profiles/cgroups_%u.json";
 
-static const std::string CGROUP_V2_ROOT_DEFAULT = "/sys/fs/cgroup";
-
 static bool ChangeDirModeAndOwner(const std::string& path, mode_t mode, const std::string& uid,
                                   const std::string& gid, bool permissive_mode = false) {
     uid_t pw_uid = -1;
@@ -148,149 +131,15 @@
     return true;
 }
 
-static void MergeCgroupToDescriptors(std::map<std::string, CgroupDescriptor>* descriptors,
-                                     const Json::Value& cgroup, const std::string& name,
-                                     const std::string& root_path, int cgroups_version) {
-    const std::string cgroup_path = cgroup["Path"].asString();
-    std::string path;
-
-    if (!root_path.empty()) {
-        path = root_path;
-        if (cgroup_path != ".") {
-            path += "/";
-            path += cgroup_path;
-        }
-    } else {
-        path = cgroup_path;
-    }
-
-    uint32_t controller_flags = 0;
-
-    if (cgroup["NeedsActivation"].isBool() && cgroup["NeedsActivation"].asBool()) {
-        controller_flags |= CGROUPRC_CONTROLLER_FLAG_NEEDS_ACTIVATION;
-    }
-
-    if (cgroup["Optional"].isBool() && cgroup["Optional"].asBool()) {
-        controller_flags |= CGROUPRC_CONTROLLER_FLAG_OPTIONAL;
-    }
-
-    uint32_t max_activation_depth = UINT32_MAX;
-    if (cgroup.isMember("MaxActivationDepth")) {
-        max_activation_depth = cgroup["MaxActivationDepth"].asUInt();
-    }
-
-    CgroupDescriptor descriptor(
-            cgroups_version, name, path, std::strtoul(cgroup["Mode"].asString().c_str(), 0, 8),
-            cgroup["UID"].asString(), cgroup["GID"].asString(), controller_flags,
-            max_activation_depth);
-
-    auto iter = descriptors->find(name);
-    if (iter == descriptors->end()) {
-        descriptors->emplace(name, descriptor);
-    } else {
-        iter->second = descriptor;
-    }
-}
-
-static const bool force_memcg_v2 = android::libprocessgroup_flags::force_memcg_v2();
-
-static bool ReadDescriptorsFromFile(const std::string& file_name,
-                                    std::map<std::string, CgroupDescriptor>* descriptors) {
-    std::vector<CgroupDescriptor> result;
-    std::string json_doc;
-
-    if (!android::base::ReadFileToString(file_name, &json_doc)) {
-        PLOG(ERROR) << "Failed to read task profiles from " << file_name;
-        return false;
-    }
-
-    Json::CharReaderBuilder builder;
-    std::unique_ptr<Json::CharReader> reader(builder.newCharReader());
-    Json::Value root;
-    std::string errorMessage;
-    if (!reader->parse(&*json_doc.begin(), &*json_doc.end(), &root, &errorMessage)) {
-        LOG(ERROR) << "Failed to parse cgroups description: " << errorMessage;
-        return false;
-    }
-
-    if (root.isMember("Cgroups")) {
-        const Json::Value& cgroups = root["Cgroups"];
-        for (Json::Value::ArrayIndex i = 0; i < cgroups.size(); ++i) {
-            std::string name = cgroups[i]["Controller"].asString();
-
-            if (force_memcg_v2 && name == "memory") continue;
-
-            MergeCgroupToDescriptors(descriptors, cgroups[i], name, "", 1);
-        }
-    }
-
-    bool memcgv2_present = false;
-    std::string root_path;
-    if (root.isMember("Cgroups2")) {
-        const Json::Value& cgroups2 = root["Cgroups2"];
-        root_path = cgroups2["Path"].asString();
-        MergeCgroupToDescriptors(descriptors, cgroups2, CGROUPV2_HIERARCHY_NAME, "", 2);
-
-        const Json::Value& childGroups = cgroups2["Controllers"];
-        for (Json::Value::ArrayIndex i = 0; i < childGroups.size(); ++i) {
-            std::string name = childGroups[i]["Controller"].asString();
-
-            if (force_memcg_v2 && name == "memory") memcgv2_present = true;
-
-            MergeCgroupToDescriptors(descriptors, childGroups[i], name, root_path, 2);
-        }
-    }
-
-    if (force_memcg_v2 && !memcgv2_present) {
-        LOG(INFO) << "Forcing memcg to v2 hierarchy";
-        Json::Value memcgv2;
-        memcgv2["Controller"] = "memory";
-        memcgv2["NeedsActivation"] = true;
-        memcgv2["Path"] = ".";
-        memcgv2["Optional"] = true;  // In case of cgroup_disabled=memory, so we can still boot
-        MergeCgroupToDescriptors(descriptors, memcgv2, "memory",
-                                 root_path.empty() ? CGROUP_V2_ROOT_DEFAULT : root_path, 2);
-    }
-
-    return true;
-}
-
-static bool ReadDescriptors(std::map<std::string, CgroupDescriptor>* descriptors) {
-    // load system cgroup descriptors
-    if (!ReadDescriptorsFromFile(CGROUPS_DESC_FILE, descriptors)) {
-        return false;
-    }
-
-    // load API-level specific system cgroups descriptors if available
-    unsigned int api_level = GetUintProperty<unsigned int>("ro.product.first_api_level", 0);
-    if (api_level > 0) {
-        std::string api_cgroups_path =
-                android::base::StringPrintf(TEMPLATE_CGROUPS_DESC_API_FILE, api_level);
-        if (!access(api_cgroups_path.c_str(), F_OK) || errno != ENOENT) {
-            if (!ReadDescriptorsFromFile(api_cgroups_path, descriptors)) {
-                return false;
-            }
-        }
-    }
-
-    // load vendor cgroup descriptors if the file exists
-    if (!access(CGROUPS_DESC_VENDOR_FILE, F_OK) &&
-        !ReadDescriptorsFromFile(CGROUPS_DESC_VENDOR_FILE, descriptors)) {
-        return false;
-    }
-
-    return true;
-}
-
 // To avoid issues in sdk_mac build
 #if defined(__ANDROID__)
 
-static bool IsOptionalController(const format::CgroupController* controller) {
+static bool IsOptionalController(const CgroupController* controller) {
     return controller->flags() & CGROUPRC_CONTROLLER_FLAG_OPTIONAL;
 }
 
 static bool MountV2CgroupController(const CgroupDescriptor& descriptor) {
-    const format::CgroupController* controller = descriptor.controller();
+    const CgroupController* controller = descriptor.controller();
 
     // /sys/fs/cgroup is created by cgroup2 with specific selinux permissions,
     // try to create again in case the mount point is changed
@@ -324,7 +173,7 @@
 }
 
 static bool ActivateV2CgroupController(const CgroupDescriptor& descriptor) {
-    const format::CgroupController* controller = descriptor.controller();
+    const CgroupController* controller = descriptor.controller();
 
     if (!Mkdir(controller->path(), descriptor.mode(), descriptor.uid(), descriptor.gid())) {
         LOG(ERROR) << "Failed to create directory for " << controller->name() << " cgroup";
@@ -338,7 +187,7 @@
         std::string path = controller->path();
         path += "/cgroup.subtree_control";
 
-        if (!base::WriteStringToFile(str, path)) {
+        if (!android::base::WriteStringToFile(str, path)) {
             if (IsOptionalController(controller)) {
                 PLOG(INFO) << "Failed to activate optional controller " << controller->name()
                            << " at " << path;
@@ -353,7 +202,7 @@
 }
 
 static bool MountV1CgroupController(const CgroupDescriptor& descriptor) {
-    const format::CgroupController* controller = descriptor.controller();
+    const CgroupController* controller = descriptor.controller();
 
     // mkdir <path> [mode] [owner] [group]
     if (!Mkdir(controller->path(), descriptor.mode(), descriptor.uid(), descriptor.gid())) {
@@ -388,7 +237,7 @@
 }
 
 static bool SetupCgroup(const CgroupDescriptor& descriptor) {
-    const format::CgroupController* controller = descriptor.controller();
+    const CgroupController* controller = descriptor.controller();
 
     if (controller->version() == 2) {
         if (!strcmp(controller->name(), CGROUPV2_HIERARCHY_NAME)) {
@@ -410,35 +259,6 @@
 
 #endif
 
-static bool WriteRcFile(const std::map<std::string, CgroupDescriptor>& descriptors) {
-    unique_fd fd(TEMP_FAILURE_RETRY(open(CGROUPS_RC_PATH, O_CREAT | O_WRONLY | O_TRUNC | O_CLOEXEC,
-                                         S_IRUSR | S_IRGRP | S_IROTH)));
-    if (fd < 0) {
-        PLOG(ERROR) << "open() failed for " << CGROUPS_RC_PATH;
-        return false;
-    }
-
-    format::CgroupFile fl;
-    fl.version_ = format::CgroupFile::FILE_CURR_VERSION;
-    fl.controller_count_ = descriptors.size();
-    int ret = TEMP_FAILURE_RETRY(write(fd, &fl, sizeof(fl)));
-    if (ret < 0) {
-        PLOG(ERROR) << "write() failed for " << CGROUPS_RC_PATH;
-        return false;
-    }
-
-    for (const auto& [name, descriptor] : descriptors) {
-        ret = TEMP_FAILURE_RETRY(
-                write(fd, descriptor.controller(), sizeof(format::CgroupController)));
-        if (ret < 0) {
-            PLOG(ERROR) << "write() failed for " << CGROUPS_RC_PATH;
-            return false;
-        }
-    }
-
-    return true;
-}
-
 CgroupDescriptor::CgroupDescriptor(uint32_t version, const std::string& name,
                                    const std::string& path, mode_t mode, const std::string& uid,
                                    const std::string& gid, uint32_t flags,
@@ -458,9 +278,6 @@
     controller_.set_flags(flags);
 }
 
-}  // namespace cgrouprc
-}  // namespace android
-
 static std::optional<bool> MGLRUDisabled() {
     const std::string file_name = "/sys/kernel/mm/lru_gen/enabled";
     std::string content;
@@ -472,9 +289,8 @@
     return content == "0x0000";
 }
 
-static std::optional<bool> MEMCGDisabled(
-        const std::map<std::string, android::cgrouprc::CgroupDescriptor>& descriptors) {
-    std::string cgroup_v2_root = android::cgrouprc::CGROUP_V2_ROOT_DEFAULT;
+static std::optional<bool> MEMCGDisabled(const CgroupDescriptorMap& descriptors) {
+    std::string cgroup_v2_root = CGROUP_V2_ROOT_DEFAULT;
     const auto it = descriptors.find(CGROUPV2_HIERARCHY_NAME);
     if (it == descriptors.end()) {
         LOG(WARNING) << "No Cgroups2 path found in cgroups.json. Vendor has modified Android, and "
@@ -495,14 +311,10 @@
     return content.find("memory") == std::string::npos;
 }
 
-static bool CreateV2SubHierarchy(
-        const std::string& path,
-        const std::map<std::string, android::cgrouprc::CgroupDescriptor>& descriptors) {
-    using namespace android::cgrouprc;
-
+static bool CreateV2SubHierarchy(const std::string& path, const CgroupDescriptorMap& descriptors) {
     const auto cgv2_iter = descriptors.find(CGROUPV2_HIERARCHY_NAME);
     if (cgv2_iter == descriptors.end()) return false;
-    const android::cgrouprc::CgroupDescriptor cgv2_descriptor = cgv2_iter->second;
+    const CgroupDescriptor cgv2_descriptor = cgv2_iter->second;
 
     if (!Mkdir(path, cgv2_descriptor.mode(), cgv2_descriptor.uid(), cgv2_descriptor.gid())) {
         PLOG(ERROR) << "Failed to create directory for " << path;
@@ -512,10 +324,10 @@
     // Activate all v2 controllers in path so they can be activated in
     // children as they are created.
     for (const auto& [name, descriptor] : descriptors) {
-        const format::CgroupController* controller = descriptor.controller();
+        const CgroupController* controller = descriptor.controller();
         std::uint32_t flags = controller->flags();
         std::uint32_t max_activation_depth = controller->max_activation_depth();
-        const int depth = util::GetCgroupDepth(controller->path(), path);
+        const int depth = GetCgroupDepth(controller->path(), path);
 
         if (controller->version() == 2 && name != CGROUPV2_HIERARCHY_NAME &&
             flags & CGROUPRC_CONTROLLER_FLAG_NEEDS_ACTIVATION && depth < max_activation_depth) {
@@ -535,22 +347,13 @@
 }
 
 bool CgroupSetup() {
-    using namespace android::cgrouprc;
-
-    std::map<std::string, CgroupDescriptor> descriptors;
+    CgroupDescriptorMap descriptors;
 
     if (getpid() != 1) {
         LOG(ERROR) << "Cgroup setup can be done only by init process";
         return false;
     }
 
-    // Make sure we do this only one time. No need for std::call_once because
-    // init is a single-threaded process
-    if (access(CGROUPS_RC_PATH, F_OK) == 0) {
-        LOG(WARNING) << "Attempt to call CgroupSetup() more than once";
-        return true;
-    }
-
     // load cgroups.json file
     if (!ReadDescriptors(&descriptors)) {
         LOG(ERROR) << "Failed to load cgroup description file";
@@ -559,15 +362,18 @@
 
     // setup cgroups
     for (auto& [name, descriptor] : descriptors) {
-        if (SetupCgroup(descriptor)) {
-            descriptor.set_mounted(true);
-        } else {
+        if (descriptor.controller()->flags() & CGROUPRC_CONTROLLER_FLAG_MOUNTED) {
+            LOG(WARNING) << "Attempt to call CgroupSetup() more than once";
+            return true;
+        }
+
+        if (!SetupCgroup(descriptor)) {
             // issue a warning and proceed with the next cgroup
             LOG(WARNING) << "Failed to setup " << name << " cgroup";
         }
     }
 
-    if (force_memcg_v2) {
+    if (android::libprocessgroup_flags::force_memcg_v2()) {
         if (MGLRUDisabled().value_or(false)) {
             LOG(WARNING) << "Memcg forced to v2 hierarchy with MGLRU disabled! "
                          << "Global reclaim performance will suffer.";
@@ -593,26 +399,5 @@
         }
     }
 
-    // mkdir <CGROUPS_RC_DIR> 0711 system system
-    if (!Mkdir(android::base::Dirname(CGROUPS_RC_PATH), 0711, "system", "system")) {
-        LOG(ERROR) << "Failed to create directory for " << CGROUPS_RC_PATH << " file";
-        return false;
-    }
-
-    // Generate <CGROUPS_RC_FILE> file which can be directly mmapped into
-    // process memory. This optimizes performance, memory usage
-    // and limits infrormation shared with unprivileged processes
-    // to the minimum subset of information from cgroups.json
-    if (!WriteRcFile(descriptors)) {
-        LOG(ERROR) << "Failed to write " << CGROUPS_RC_PATH << " file";
-        return false;
-    }
-
-    // chmod 0644 <CGROUPS_RC_PATH>
-    if (fchmodat(AT_FDCWD, CGROUPS_RC_PATH, 0644, AT_SYMLINK_NOFOLLOW) < 0) {
-        PLOG(ERROR) << "fchmodat() failed";
-        return false;
-    }
-
     return true;
 }
diff --git a/libprocessgroup/util/Android.bp b/libprocessgroup/util/Android.bp
index 54ba69b..1c74d4e 100644
--- a/libprocessgroup/util/Android.bp
+++ b/libprocessgroup/util/Android.bp
@@ -37,8 +37,16 @@
         "include",
     ],
     srcs: [
+        "cgroup_controller.cpp",
+        "cgroup_descriptor.cpp",
         "util.cpp",
     ],
+    shared_libs: [
+        "libbase",
+    ],
+    static_libs: [
+        "libjsoncpp",
+    ],
     defaults: ["libprocessgroup_build_flags_cc"],
 }
 
diff --git a/libprocessgroup/cgrouprc_format/cgroup_controller.cpp b/libprocessgroup/util/cgroup_controller.cpp
similarity index 89%
rename from libprocessgroup/cgrouprc_format/cgroup_controller.cpp
rename to libprocessgroup/util/cgroup_controller.cpp
index 0dd909a..fb41680 100644
--- a/libprocessgroup/cgrouprc_format/cgroup_controller.cpp
+++ b/libprocessgroup/util/cgroup_controller.cpp
@@ -14,11 +14,9 @@
  * limitations under the License.
  */
 
-#include <processgroup/format/cgroup_controller.h>
+#include <processgroup/cgroup_controller.h>
 
-namespace android {
-namespace cgrouprc {
-namespace format {
+#include <cstring>
 
 CgroupController::CgroupController(uint32_t version, uint32_t flags, const std::string& name,
                                    const std::string& path, uint32_t max_activation_depth)
@@ -54,8 +52,4 @@
 
 void CgroupController::set_flags(uint32_t flags) {
     flags_ = flags;
-}
-
-}  // namespace format
-}  // namespace cgrouprc
-}  // namespace android
+}
\ No newline at end of file
diff --git a/libprocessgroup/util/cgroup_descriptor.cpp b/libprocessgroup/util/cgroup_descriptor.cpp
new file mode 100644
index 0000000..4d3347f
--- /dev/null
+++ b/libprocessgroup/util/cgroup_descriptor.cpp
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <processgroup/cgroup_descriptor.h>
+
+#include <processgroup/util.h>  // For flag values
+
+CgroupDescriptor::CgroupDescriptor(uint32_t version, const std::string& name,
+                                   const std::string& path, mode_t mode, const std::string& uid,
+                                   const std::string& gid, uint32_t flags,
+                                   uint32_t max_activation_depth)
+    : controller_(version, flags, name, path, max_activation_depth),
+      mode_(mode),
+      uid_(uid),
+      gid_(gid) {}
+
+void CgroupDescriptor::set_mounted(bool mounted) {
+    uint32_t flags = controller_.flags();
+    if (mounted) {
+        flags |= CGROUPRC_CONTROLLER_FLAG_MOUNTED;
+    } else {
+        flags &= ~CGROUPRC_CONTROLLER_FLAG_MOUNTED;
+    }
+    controller_.set_flags(flags);
+}
diff --git a/libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_controller.h b/libprocessgroup/util/include/processgroup/cgroup_controller.h
similarity index 86%
rename from libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_controller.h
rename to libprocessgroup/util/include/processgroup/cgroup_controller.h
index c0c1f60..fe6a829 100644
--- a/libprocessgroup/cgrouprc_format/include/processgroup/format/cgroup_controller.h
+++ b/libprocessgroup/util/include/processgroup/cgroup_controller.h
@@ -20,11 +20,7 @@
 #include <cstdint>
 #include <string>
 
-namespace android {
-namespace cgrouprc {
-namespace format {
-
-// Minimal controller description to be mmapped into process address space
+// Minimal controller description
 struct CgroupController {
   public:
     CgroupController() = default;
@@ -48,8 +44,4 @@
     uint32_t max_activation_depth_ = UINT32_MAX;
     char name_[CGROUP_NAME_BUF_SZ] = {};
     char path_[CGROUP_PATH_BUF_SZ] = {};
-};
-
-}  // namespace format
-}  // namespace cgrouprc
-}  // namespace android
+};
\ No newline at end of file
diff --git a/libprocessgroup/util/include/processgroup/cgroup_descriptor.h b/libprocessgroup/util/include/processgroup/cgroup_descriptor.h
new file mode 100644
index 0000000..1afd2ee
--- /dev/null
+++ b/libprocessgroup/util/include/processgroup/cgroup_descriptor.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <cstdint>
+#include <string>
+
+#include <sys/stat.h>
+
+#include <processgroup/cgroup_controller.h>
+
+// Complete controller description for mounting cgroups
+class CgroupDescriptor {
+  public:
+    CgroupDescriptor(uint32_t version, const std::string& name, const std::string& path,
+                     mode_t mode, const std::string& uid, const std::string& gid, uint32_t flags,
+                     uint32_t max_activation_depth);
+
+    const CgroupController* controller() const { return &controller_; }
+    mode_t mode() const { return mode_; }
+    std::string uid() const { return uid_; }
+    std::string gid() const { return gid_; }
+
+    void set_mounted(bool mounted);
+
+  private:
+    CgroupController controller_;
+    mode_t mode_ = 0;
+    std::string uid_;
+    std::string gid_;
+};
diff --git a/libprocessgroup/util/include/processgroup/util.h b/libprocessgroup/util/include/processgroup/util.h
index 8d013af..d592a63 100644
--- a/libprocessgroup/util/include/processgroup/util.h
+++ b/libprocessgroup/util/include/processgroup/util.h
@@ -16,10 +16,18 @@
 
 #pragma once
 
+#include <map>
 #include <string>
 
-namespace util {
+#include "cgroup_descriptor.h"
+
+// Duplicated from cgrouprc.h. Don't depend on libcgrouprc here.
+#define CGROUPRC_CONTROLLER_FLAG_MOUNTED 0x1
+#define CGROUPRC_CONTROLLER_FLAG_NEEDS_ACTIVATION 0x2
+#define CGROUPRC_CONTROLLER_FLAG_OPTIONAL 0x4
 
 unsigned int GetCgroupDepth(const std::string& controller_root, const std::string& cgroup_path);
 
-}  // namespace util
+using CgroupControllerName = std::string;
+using CgroupDescriptorMap = std::map<CgroupControllerName, CgroupDescriptor>;
+bool ReadDescriptors(CgroupDescriptorMap* descriptors);
diff --git a/libprocessgroup/util/tests/util.cpp b/libprocessgroup/util/tests/util.cpp
index 1de7d6f..6caef8e 100644
--- a/libprocessgroup/util/tests/util.cpp
+++ b/libprocessgroup/util/tests/util.cpp
@@ -18,8 +18,6 @@
 
 #include "gtest/gtest.h"
 
-using util::GetCgroupDepth;
-
 TEST(EmptyInputs, bothEmpty) {
     EXPECT_EQ(GetCgroupDepth({}, {}), 0);
 }
diff --git a/libprocessgroup/util/util.cpp b/libprocessgroup/util/util.cpp
index 9b88a22..bff4c6f 100644
--- a/libprocessgroup/util/util.cpp
+++ b/libprocessgroup/util/util.cpp
@@ -18,9 +18,33 @@
 
 #include <algorithm>
 #include <iterator>
+#include <optional>
+#include <string_view>
+
+#include <mntent.h>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/properties.h>
+#include <android-base/stringprintf.h>
+#include <json/reader.h>
+#include <json/value.h>
+
+#include "../build_flags.h"
+#include "../internal.h"
+
+using android::base::GetUintProperty;
 
 namespace {
 
+constexpr const char* CGROUPS_DESC_FILE = "/etc/cgroups.json";
+constexpr const char* CGROUPS_DESC_VENDOR_FILE = "/vendor/etc/cgroups.json";
+constexpr const char* TEMPLATE_CGROUPS_DESC_API_FILE = "/etc/task_profiles/cgroups_%u.json";
+
+// This should match the publicly declared value in processgroup.h,
+// but we don't want this library to depend on libprocessgroup.
+constexpr std::string CGROUPV2_HIERARCHY_NAME_INTERNAL = "cgroup2";
+
 const char SEP = '/';
 
 std::string DeduplicateAndTrimSeparators(const std::string& path) {
@@ -42,9 +66,135 @@
     return ret;
 }
 
+void MergeCgroupToDescriptors(CgroupDescriptorMap* descriptors, const Json::Value& cgroup,
+                              const std::string& name, const std::string& root_path,
+                              int cgroups_version) {
+    const std::string cgroup_path = cgroup["Path"].asString();
+    std::string path;
+
+    if (!root_path.empty()) {
+        path = root_path;
+        if (cgroup_path != ".") {
+            path += "/";
+            path += cgroup_path;
+        }
+    } else {
+        path = cgroup_path;
+    }
+
+    uint32_t controller_flags = 0;
+
+    if (cgroup["NeedsActivation"].isBool() && cgroup["NeedsActivation"].asBool()) {
+        controller_flags |= CGROUPRC_CONTROLLER_FLAG_NEEDS_ACTIVATION;
+    }
+
+    if (cgroup["Optional"].isBool() && cgroup["Optional"].asBool()) {
+        controller_flags |= CGROUPRC_CONTROLLER_FLAG_OPTIONAL;
+    }
+
+    uint32_t max_activation_depth = UINT32_MAX;
+    if (cgroup.isMember("MaxActivationDepth")) {
+        max_activation_depth = cgroup["MaxActivationDepth"].asUInt();
+    }
+
+    CgroupDescriptor descriptor(
+            cgroups_version, name, path, std::strtoul(cgroup["Mode"].asString().c_str(), 0, 8),
+            cgroup["UID"].asString(), cgroup["GID"].asString(), controller_flags,
+            max_activation_depth);
+
+    auto iter = descriptors->find(name);
+    if (iter == descriptors->end()) {
+        descriptors->emplace(name, descriptor);
+    } else {
+        iter->second = descriptor;
+    }
+}
+
+bool ReadDescriptorsFromFile(const std::string& file_name, CgroupDescriptorMap* descriptors) {
+    static constexpr bool force_memcg_v2 = android::libprocessgroup_flags::force_memcg_v2();
+    std::vector<CgroupDescriptor> result;
+    std::string json_doc;
+
+    if (!android::base::ReadFileToString(file_name, &json_doc)) {
+        PLOG(ERROR) << "Failed to read task profiles from " << file_name;
+        return false;
+    }
+
+    Json::CharReaderBuilder builder;
+    std::unique_ptr<Json::CharReader> reader(builder.newCharReader());
+    Json::Value root;
+    std::string errorMessage;
+    if (!reader->parse(&*json_doc.begin(), &*json_doc.end(), &root, &errorMessage)) {
+        LOG(ERROR) << "Failed to parse cgroups description: " << errorMessage;
+        return false;
+    }
+
+    if (root.isMember("Cgroups")) {
+        const Json::Value& cgroups = root["Cgroups"];
+        for (Json::Value::ArrayIndex i = 0; i < cgroups.size(); ++i) {
+            std::string name = cgroups[i]["Controller"].asString();
+
+            if (force_memcg_v2 && name == "memory") continue;
+
+            MergeCgroupToDescriptors(descriptors, cgroups[i], name, "", 1);
+        }
+    }
+
+    bool memcgv2_present = false;
+    std::string root_path;
+    if (root.isMember("Cgroups2")) {
+        const Json::Value& cgroups2 = root["Cgroups2"];
+        root_path = cgroups2["Path"].asString();
+        MergeCgroupToDescriptors(descriptors, cgroups2, CGROUPV2_HIERARCHY_NAME_INTERNAL, "", 2);
+
+        const Json::Value& childGroups = cgroups2["Controllers"];
+        for (Json::Value::ArrayIndex i = 0; i < childGroups.size(); ++i) {
+            std::string name = childGroups[i]["Controller"].asString();
+
+            if (force_memcg_v2 && name == "memory") memcgv2_present = true;
+
+            MergeCgroupToDescriptors(descriptors, childGroups[i], name, root_path, 2);
+        }
+    }
+
+    if (force_memcg_v2 && !memcgv2_present) {
+        LOG(INFO) << "Forcing memcg to v2 hierarchy";
+        Json::Value memcgv2;
+        memcgv2["Controller"] = "memory";
+        memcgv2["NeedsActivation"] = true;
+        memcgv2["Path"] = ".";
+        memcgv2["Optional"] = true;  // In case of cgroup_disabled=memory, so we can still boot
+        MergeCgroupToDescriptors(descriptors, memcgv2, "memory",
+                                 root_path.empty() ? CGROUP_V2_ROOT_DEFAULT : root_path, 2);
+    }
+
+    return true;
+}
+
+using MountDir = std::string;
+using MountOpts = std::string;
+static std::optional<std::map<MountDir, MountOpts>> ReadCgroupV1Mounts() {
+    FILE* fp = setmntent("/proc/mounts", "r");
+    if (fp == nullptr) {
+        PLOG(ERROR) << "Failed to read mounts";
+        return std::nullopt;
+    }
+
+    std::map<MountDir, MountOpts> mounts;
+    const std::string_view CGROUP_V1_TYPE = "cgroup";
+    for (mntent* mentry = getmntent(fp); mentry != nullptr; mentry = getmntent(fp)) {
+        if (mentry->mnt_type && CGROUP_V1_TYPE == mentry->mnt_type &&
+            mentry->mnt_dir && mentry->mnt_opts) {
+            mounts[mentry->mnt_dir] = mentry->mnt_opts;
+        }
+    }
+    endmntent(fp);
+
+    return mounts;
+}
+
 }  // anonymous namespace
 
-namespace util {
 
 unsigned int GetCgroupDepth(const std::string& controller_root, const std::string& cgroup_path) {
     const std::string deduped_root = DeduplicateAndTrimSeparators(controller_root);
@@ -56,4 +206,47 @@
     return std::count(deduped_path.begin() + deduped_root.size(), deduped_path.end(), SEP);
 }
 
-}  // namespace util
+bool ReadDescriptors(CgroupDescriptorMap* descriptors) {
+    // load system cgroup descriptors
+    if (!ReadDescriptorsFromFile(CGROUPS_DESC_FILE, descriptors)) {
+        return false;
+    }
+
+    // load API-level specific system cgroups descriptors if available
+    unsigned int api_level = GetUintProperty<unsigned int>("ro.product.first_api_level", 0);
+    if (api_level > 0) {
+        std::string api_cgroups_path =
+                android::base::StringPrintf(TEMPLATE_CGROUPS_DESC_API_FILE, api_level);
+        if (!access(api_cgroups_path.c_str(), F_OK) || errno != ENOENT) {
+            if (!ReadDescriptorsFromFile(api_cgroups_path, descriptors)) {
+                return false;
+            }
+        }
+    }
+
+    // load vendor cgroup descriptors if the file exists
+    if (!access(CGROUPS_DESC_VENDOR_FILE, F_OK) &&
+        !ReadDescriptorsFromFile(CGROUPS_DESC_VENDOR_FILE, descriptors)) {
+        return false;
+    }
+
+    // check for v1 mount/usability status
+    std::optional<std::map<MountDir, MountOpts>> v1Mounts;
+    for (auto& [name, descriptor] : *descriptors) {
+        const CgroupController* const controller = descriptor.controller();
+
+        if (controller->version() != 1) continue;
+
+        // Read only once, and only if we have at least one v1 controller
+        if (!v1Mounts) {
+            v1Mounts = ReadCgroupV1Mounts();
+            if (!v1Mounts) return false;
+        }
+
+        if (const auto it = v1Mounts->find(controller->path()); it != v1Mounts->end()) {
+            if (it->second.contains(controller->name())) descriptor.set_mounted(true);
+        }
+    }
+
+    return true;
+}