diff --git a/idea-plugin/README.md b/idea-plugin/README.md
index dea906a983c6479388bef68031afd74e3543cb32..9833e6e6751e5159ec6c0fcbdafc071cd2ae0582 100644
--- a/idea-plugin/README.md
+++ b/idea-plugin/README.md
@@ -7,16 +7,16 @@
 ## <font color="green">Build</font>
 ```
 cd p3c-idea
-gradle clean buildPlugin
+../gradlew clean buildPlugin
 ```
 
 ## <font color="green">Run plugin</font>
 
 ```
 cd p3c-idea
-gradle runIde
+../gradlew runIde
 # run specific IDEA
-gradle runIde -Pidea_version=14.1.7
+../gradlew runIde -Pidea_version=14.1.7
 ```
 
 ## <font color="green">Use p3c-common as your plugin dependency</font>
diff --git a/idea-plugin/gradle.properties b/idea-plugin/gradle.properties
index 9c338100ab759e84eeaea811cd50346aca4f46bc..637c314fab37295bd656d19e6661a972d428d86b 100644
--- a/idea-plugin/gradle.properties
+++ b/idea-plugin/gradle.properties
@@ -1,8 +1,7 @@
-kotlin_version=1.3.50
-#idea_version=171.3780.15
-idea_version=145.258.11
+kotlin_version=1.3.72
+idea_version=2018.3
 plugin_name=Alibaba Java Coding Guidelines
 gradle_jetbrains_version=0.4.5
 systemProp.file.encoding=UTF-8
 
-plugin_version=2.0.2
+plugin_version=2.1.0
diff --git a/idea-plugin/gradle/wrapper/gradle-wrapper.jar b/idea-plugin/gradle/wrapper/gradle-wrapper.jar
index 51288f9c2f05faf8d42e1a751a387ca7923882c3..87b738cbd051603d91cc39de6cb000dd98fe6b02 100644
Binary files a/idea-plugin/gradle/wrapper/gradle-wrapper.jar and b/idea-plugin/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/idea-plugin/gradle/wrapper/gradle-wrapper.properties b/idea-plugin/gradle/wrapper/gradle-wrapper.properties
index 29bf84a4b5a47b879ed8e20cd7e49efe1748e3ba..bb8b2fc26b2e572c79d7212a4f6f11057c6787f7 100644
--- a/idea-plugin/gradle/wrapper/gradle-wrapper.properties
+++ b/idea-plugin/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,5 @@
-#Wed Nov 30 15:31:46 CST 2016
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.5.1-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.1.1-bin.zip
diff --git a/idea-plugin/gradlew b/idea-plugin/gradlew
index 4453ccea33d960069d9137ee65f6b21fc65e7e92..af6708ff229fda75da4f7cc4da4747217bac4d53 100755
--- a/idea-plugin/gradlew
+++ b/idea-plugin/gradlew
@@ -28,16 +28,16 @@ APP_NAME="Gradle"
 APP_BASE_NAME=`basename "$0"`
 
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS=""
+DEFAULT_JVM_OPTS='"-Xmx64m"'
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD="maximum"
 
-warn ( ) {
+warn () {
     echo "$*"
 }
 
-die ( ) {
+die () {
     echo
     echo "$*"
     echo
@@ -155,7 +155,7 @@ if $cygwin ; then
 fi
 
 # Escape application args
-save ( ) {
+save () {
     for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
     echo " "
 }
diff --git a/idea-plugin/gradlew.bat b/idea-plugin/gradlew.bat
index f9553162f122c71b34635112e717c3e733b5b212..6d57edc706c93465988754383a2d7ff353d4e79f 100644
--- a/idea-plugin/gradlew.bat
+++ b/idea-plugin/gradlew.bat
@@ -14,7 +14,7 @@ set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
 @rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-set DEFAULT_JVM_OPTS=
+set DEFAULT_JVM_OPTS="-Xmx64m"
 
 @rem Find java.exe
 if defined JAVA_HOME goto findJavaFromJavaHome
diff --git a/idea-plugin/p3c-common/src/main/kotlin/com/alibaba/p3c/idea/action/PmdGlobalInspectionContextImpl.kt b/idea-plugin/p3c-common/src/main/kotlin/com/alibaba/p3c/idea/action/PmdGlobalInspectionContextImpl.kt
index 7207622a9888d6878df9a77c220a40e0f8ae78bd..f7c277872854957f80b4ab316f57adf10bc6c2d4 100644
--- a/idea-plugin/p3c-common/src/main/kotlin/com/alibaba/p3c/idea/action/PmdGlobalInspectionContextImpl.kt
+++ b/idea-plugin/p3c-common/src/main/kotlin/com/alibaba/p3c/idea/action/PmdGlobalInspectionContextImpl.kt
@@ -6,6 +6,7 @@ import com.alibaba.p3c.idea.inspection.AliLocalInspectionToolProvider
 import com.alibaba.p3c.idea.inspection.PmdRuleInspectionIdentify
 import com.alibaba.p3c.idea.pmd.AliPmdProcessor
 import com.intellij.analysis.AnalysisScope
+import com.intellij.codeInsight.daemon.ProblemHighlightFilter
 import com.intellij.codeInsight.daemon.impl.DaemonProgressIndicator
 import com.intellij.codeInspection.ex.GlobalInspectionContextImpl
 import com.intellij.codeInspection.ui.InspectionResultsView
@@ -14,21 +15,32 @@ import com.intellij.concurrency.JobLauncherImpl
 import com.intellij.concurrency.SensitiveProgressWrapper
 import com.intellij.diagnostic.ThreadDumper
 import com.intellij.openapi.application.ApplicationManager
+import com.intellij.openapi.application.ReadAction
 import com.intellij.openapi.application.ex.ApplicationManagerEx
 import com.intellij.openapi.diagnostic.Logger
+import com.intellij.openapi.editor.Document
 import com.intellij.openapi.progress.ProcessCanceledException
 import com.intellij.openapi.progress.ProgressIndicator
 import com.intellij.openapi.progress.ProgressIndicatorProvider
 import com.intellij.openapi.progress.ProgressManager
+import com.intellij.openapi.progress.Task.Backgroundable
+import com.intellij.openapi.progress.impl.CoreProgressManager
 import com.intellij.openapi.progress.util.ProgressIndicatorUtils
 import com.intellij.openapi.project.DumbService
 import com.intellij.openapi.project.Project
-import com.intellij.openapi.project.ProjectUtilCore
+import com.intellij.openapi.project.displayUrlRelativeToProject
+import com.intellij.openapi.project.isProjectOrWorkspaceFile
+import com.intellij.openapi.roots.FileIndex
+import com.intellij.openapi.roots.ProjectRootManager
 import com.intellij.openapi.util.Disposer
 import com.intellij.openapi.util.EmptyRunnable
 import com.intellij.openapi.util.NotNullLazyValue
 import com.intellij.openapi.vfs.VirtualFile
+import com.intellij.psi.PsiBinaryFile
+import com.intellij.psi.PsiDocumentManager
 import com.intellij.psi.PsiFile
+import com.intellij.psi.PsiManager
+import com.intellij.psi.SingleRootFileViewProvider
 import com.intellij.psi.search.LocalSearchScope
 import com.intellij.psi.search.SearchScope
 import com.intellij.psi.util.PsiUtilCore
@@ -123,20 +135,7 @@ class PmdGlobalInspectionContextImpl(
         val localScopeFiles: MutableSet<VirtualFile>? = if (searchScope is LocalSearchScope) THashSet() else null
         val filesToInspect: BlockingQueue<PsiFile> = ArrayBlockingQueue(1000)
         val iteratingIndicator: ProgressIndicator = SensitiveProgressWrapper(progressIndicator)
-        val startIterateScopeInBackground = ReflectionUtil.getDeclaredMethod(
-            javaClass.superclass,
-            "startIterateScopeInBackground",
-            AnalysisScope::class.java,
-            Collection::class.java,
-            headlessEnvironment.javaClass,
-            BlockingQueue::class.java,
-            ProgressIndicator::class.java
-        )
-        requireNotNull(startIterateScopeInBackground) {
-            "method GlobalInspectionContextImpl.startIterateScopeInBackground not found in this IDEA version"
-        }
-        val future: Future<*> = startIterateScopeInBackground.invoke(
-            this,
+        val future: Future<*> = startIterateScopeInBackground(
             scope,
             localScopeFiles,
             headlessEnvironment,
@@ -219,12 +218,91 @@ class PmdGlobalInspectionContextImpl(
         ProgressManager.checkCanceled()
     }
 
+    private fun startIterateScopeInBackground(
+        scope: AnalysisScope,
+        localScopeFiles: MutableCollection<VirtualFile>?,
+        headlessEnvironment: Boolean,
+        outFilesToInspect: BlockingQueue<in PsiFile>,
+        progressIndicator: ProgressIndicator
+    ): Future<*>? {
+        val task: Backgroundable = object : Backgroundable(project, "Scanning Files to Inspect") {
+            override fun run(indicator: ProgressIndicator) {
+                try {
+                    val fileIndex: FileIndex = ProjectRootManager.getInstance(project).fileIndex
+                    scope.accept { file: VirtualFile? ->
+                        ProgressManager.checkCanceled()
+                        if (isProjectOrWorkspaceFile(file!!) || !fileIndex.isInContent(file)) return@accept true
+                        val psiFile =
+                            ReadAction.compute<PsiFile?, RuntimeException> {
+                                if (project.isDisposed) throw ProcessCanceledException()
+                                val psi = PsiManager.getInstance(project).findFile(file)
+                                val document =
+                                    psi?.let { shouldProcess(it, headlessEnvironment, localScopeFiles) }
+                                if (document != null) {
+                                    return@compute psi
+                                }
+                                null
+                            }
+                        // do not inspect binary files
+                        if (psiFile != null) {
+                            try {
+                                check(!ApplicationManager.getApplication().isReadAccessAllowed) { "Must not have read action" }
+                                outFilesToInspect.put(psiFile)
+                            } catch (e: InterruptedException) {
+                                logger.error(e)
+                            }
+                        }
+                        ProgressManager.checkCanceled()
+                        true
+                    }
+                } catch (e: ProcessCanceledException) {
+                    // ignore, but put tombstone
+                } finally {
+                    try {
+                        outFilesToInspect.put(PsiUtilCore.NULL_PSI_FILE)
+                    } catch (e: InterruptedException) {
+                        logger.error(e)
+                    }
+                }
+            }
+        }
+        return (ProgressManager.getInstance() as CoreProgressManager).runProcessWithProgressAsynchronously(
+            task,
+            progressIndicator,
+            null
+        )
+    }
+
+    private fun shouldProcess(
+        file: PsiFile,
+        headlessEnvironment: Boolean,
+        localScopeFiles: MutableCollection<VirtualFile>?
+    ): Document? {
+        val virtualFile = file.virtualFile ?: return null
+        if (isBinary(file)) return null //do not inspect binary files
+        if (isViewClosed && !headlessEnvironment) {
+            throw ProcessCanceledException()
+        }
+        if (logger.isDebugEnabled) {
+            logger.debug("Running local inspections on " + virtualFile.path)
+        }
+        if (SingleRootFileViewProvider.isTooLargeForIntelligence(virtualFile)) return null
+        if (localScopeFiles != null && !localScopeFiles.add(virtualFile)) return null
+        return if (!ProblemHighlightFilter.shouldProcessFileInBatch(file)) null else PsiDocumentManager.getInstance(
+            project
+        ).getDocument(file)
+    }
+
+    private fun isBinary(file: PsiFile): Boolean {
+        return file is PsiBinaryFile || file.fileType.isBinary
+    }
+
     private fun doPmdProcess(
         file: PsiFile,
         aliProjectComponent: AliProjectComponent,
         virtualFile: VirtualFile
     ) {
-        val url: String = ProjectUtilCore.displayUrlRelativeToProject(
+        val url: String = displayUrlRelativeToProject(
             virtualFile,
             virtualFile.presentableUrl,
             project,
diff --git a/idea-plugin/p3c-idea/src/main/resources/META-INF/plugin.xml b/idea-plugin/p3c-idea/src/main/resources/META-INF/plugin.xml
index 932d886c628424724fbef558e6f17597e894078b..0a19bf9f4af5a24e21cdca0060efa079ad495a26 100755
--- a/idea-plugin/p3c-idea/src/main/resources/META-INF/plugin.xml
+++ b/idea-plugin/p3c-idea/src/main/resources/META-INF/plugin.xml
@@ -6,6 +6,15 @@
     <change-notes>
         <![CDATA[
          <ul>
+        2.1.0
+        <li>Fix idea 2020.2 Ultimate compatibility issue</li>
+        <li>Minimum supported idea version up to 2018.3</li>
+        <li>Kotlin upgrade to 1.3.72</li>
+        <li>Disable real time inspect if file lines more than 3000 lines</li>
+        <li>Fix https://github.com/alibaba/p3c/issues/722</li>
+        <li>Fix https://github.com/alibaba/p3c/issues/620</li>
+        </ul>
+        <ul>
         2.0.2
         <li>Fix idea 2020.1 Ultimate compatibility issue</li>
         </ul>
@@ -75,7 +84,7 @@
     </change-notes>
     <vendor>alibaba</vendor>
     <version>2.0.0</version>
-    <idea-version since-build="145.0"/>
+    <idea-version since-build="183.4284"/>
     <depends optional="true">com.intellij.velocity</depends>
     <depends optional="true" config-file="p3c.xml">com.intellij.modules.java</depends>
     <depends>com.intellij.modules.platform</depends>