From 52a9dbdcd2b22bd7584b8ca403746649da37fac2 Mon Sep 17 00:00:00 2001
From: div8cn <35140268+div8cn@users.noreply.github.com>
Date: Tue, 5 Oct 2021 23:34:28 +0800
Subject: [PATCH] kvm available memory calculation optimization (#5540)

* Update LibvirtComputingResource.java

* Update LibvirtComputingResource.java

* Update LibvirtComputingResource.java

re

* Update MemStat.java

* Update MemStat.java

* Update MemStatTest.java
---
 .../java/org/apache/cloudstack/utils/linux/MemStat.java    | 7 ++++++-
 .../org/apache/cloudstack/utils/linux/MemStatTest.java     | 2 +-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/plugins/hypervisors/kvm/src/main/java/org/apache/cloudstack/utils/linux/MemStat.java b/plugins/hypervisors/kvm/src/main/java/org/apache/cloudstack/utils/linux/MemStat.java
index afcdf976be5..d62e1a24ce9 100644
--- a/plugins/hypervisors/kvm/src/main/java/org/apache/cloudstack/utils/linux/MemStat.java
+++ b/plugins/hypervisors/kvm/src/main/java/org/apache/cloudstack/utils/linux/MemStat.java
@@ -35,6 +35,7 @@ public class MemStat {
     protected final static String FREE_KEY = "MemFree";
     protected final static String CACHE_KEY = "Cached";
     protected final static String TOTAL_KEY = "MemTotal";
+    protected final static String BUFFER_KEY = "Buffers";
     long reservedMemory;
     long overCommitMemory;
 
@@ -55,7 +56,7 @@ public class MemStat {
     }
 
     public long getAvailable() {
-        return getFree() + getCache();
+        return getFree() + getCache() + getBuffer();
     }
 
     public long getFree() {
@@ -66,6 +67,10 @@ public class MemStat {
         return _memStats.get(CACHE_KEY);
     }
 
+    public long getBuffer() {
+        return _memStats.get(BUFFER_KEY);
+    }
+
     public void refresh() {
         File f = new File(MEMINFO_FILE);
         try (Scanner scanner = new Scanner(f,"UTF-8")) {
diff --git a/plugins/hypervisors/kvm/src/test/java/org/apache/cloudstack/utils/linux/MemStatTest.java b/plugins/hypervisors/kvm/src/test/java/org/apache/cloudstack/utils/linux/MemStatTest.java
index 5a2fda87d08..50d4b006e13 100644
--- a/plugins/hypervisors/kvm/src/test/java/org/apache/cloudstack/utils/linux/MemStatTest.java
+++ b/plugins/hypervisors/kvm/src/test/java/org/apache/cloudstack/utils/linux/MemStatTest.java
@@ -48,7 +48,7 @@ public class MemStatTest {
         MemStat memStat = new MemStat();
 
         Assert.assertEquals(memStat.getTotal(), 5970161664L);
-        Assert.assertEquals(memStat.getAvailable(), 2829840384L);
+        Assert.assertEquals(memStat.getAvailable(), 3164520448L);
         Assert.assertEquals(memStat.getFree(), 160514048L);
         Assert.assertEquals(memStat.getCache(), 2669326336L);
     }