From f2222aab6a00941d621b18d01e4c6c3ee2cfc60d Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@google.com>
Date: Fri, 25 Feb 2022 22:44:40 +0000
Subject: [PATCH] Introduce the ConfigureMemcg() method

The Service::Start() method is so long that its length negatively
affects readability of the code. Hence this patch that splits
Service::Start().

Test: Booted Android in Cuttlefish.
Change-Id: I972f4e60844bb0d133b1cca1fd4e06bb89fc5f37
Signed-off-by: Bart Van Assche <bvanassche@google.com>
---
 init/service.cpp | 81 +++++++++++++++++++++++++-----------------------
 init/service.h   |  1 +
 2 files changed, 44 insertions(+), 38 deletions(-)

diff --git a/init/service.cpp b/init/service.cpp
index c053761e9..a777b1b2f 100644
--- a/init/service.cpp
+++ b/init/service.cpp
@@ -425,6 +425,48 @@ Result<void> Service::CheckConsole() {
     return {};
 }
 
+// Configures the memory cgroup properties for the service.
+void Service::ConfigureMemcg() {
+    if (swappiness_ != -1) {
+        if (!setProcessGroupSwappiness(proc_attr_.uid, pid_, swappiness_)) {
+            PLOG(ERROR) << "setProcessGroupSwappiness failed";
+        }
+    }
+
+    if (soft_limit_in_bytes_ != -1) {
+        if (!setProcessGroupSoftLimit(proc_attr_.uid, pid_, soft_limit_in_bytes_)) {
+            PLOG(ERROR) << "setProcessGroupSoftLimit failed";
+        }
+    }
+
+    size_t computed_limit_in_bytes = limit_in_bytes_;
+    if (limit_percent_ != -1) {
+        long page_size = sysconf(_SC_PAGESIZE);
+        long num_pages = sysconf(_SC_PHYS_PAGES);
+        if (page_size > 0 && num_pages > 0) {
+            size_t max_mem = SIZE_MAX;
+            if (size_t(num_pages) < SIZE_MAX / size_t(page_size)) {
+                max_mem = size_t(num_pages) * size_t(page_size);
+            }
+            computed_limit_in_bytes =
+                    std::min(computed_limit_in_bytes, max_mem / 100 * limit_percent_);
+        }
+    }
+
+    if (!limit_property_.empty()) {
+        // This ends up overwriting computed_limit_in_bytes but only if the
+        // property is defined.
+        computed_limit_in_bytes =
+                android::base::GetUintProperty(limit_property_, computed_limit_in_bytes, SIZE_MAX);
+    }
+
+    if (computed_limit_in_bytes != size_t(-1)) {
+        if (!setProcessGroupLimit(proc_attr_.uid, pid_, computed_limit_in_bytes)) {
+            PLOG(ERROR) << "setProcessGroupLimit failed";
+        }
+    }
+}
+
 Result<void> Service::Start() {
     auto reboot_on_failure = make_scope_guard([this] {
         if (on_failure_reboot_target_) {
@@ -603,44 +645,7 @@ Result<void> Service::Start() {
         PLOG(ERROR) << "createProcessGroup(" << proc_attr_.uid << ", " << pid_
                     << ") failed for service '" << name_ << "'";
     } else if (use_memcg) {
-        if (swappiness_ != -1) {
-            if (!setProcessGroupSwappiness(proc_attr_.uid, pid_, swappiness_)) {
-                PLOG(ERROR) << "setProcessGroupSwappiness failed";
-            }
-        }
-
-        if (soft_limit_in_bytes_ != -1) {
-            if (!setProcessGroupSoftLimit(proc_attr_.uid, pid_, soft_limit_in_bytes_)) {
-                PLOG(ERROR) << "setProcessGroupSoftLimit failed";
-            }
-        }
-
-        size_t computed_limit_in_bytes = limit_in_bytes_;
-        if (limit_percent_ != -1) {
-            long page_size = sysconf(_SC_PAGESIZE);
-            long num_pages = sysconf(_SC_PHYS_PAGES);
-            if (page_size > 0 && num_pages > 0) {
-                size_t max_mem = SIZE_MAX;
-                if (size_t(num_pages) < SIZE_MAX / size_t(page_size)) {
-                    max_mem = size_t(num_pages) * size_t(page_size);
-                }
-                computed_limit_in_bytes =
-                        std::min(computed_limit_in_bytes, max_mem / 100 * limit_percent_);
-            }
-        }
-
-        if (!limit_property_.empty()) {
-            // This ends up overwriting computed_limit_in_bytes but only if the
-            // property is defined.
-            computed_limit_in_bytes = android::base::GetUintProperty(
-                    limit_property_, computed_limit_in_bytes, SIZE_MAX);
-        }
-
-        if (computed_limit_in_bytes != size_t(-1)) {
-            if (!setProcessGroupLimit(proc_attr_.uid, pid_, computed_limit_in_bytes)) {
-                PLOG(ERROR) << "setProcessGroupLimit failed";
-            }
-        }
+        ConfigureMemcg();
     }
 
     if (oom_score_adjust_ != DEFAULT_OOM_SCORE_ADJUST) {
diff --git a/init/service.h b/init/service.h
index 7339370ad..54c923bba 100644
--- a/init/service.h
+++ b/init/service.h
@@ -146,6 +146,7 @@ class Service {
     void SetProcessAttributesAndCaps();
     void ResetFlagsForStart();
     Result<void> CheckConsole();
+    void ConfigureMemcg();
 
     static unsigned long next_start_order_;
     static bool is_exec_service_running_;