diff --git a/core/src/main/java/hudson/matrix/LinkedLogRotator.java b/core/src/main/java/hudson/matrix/LinkedLogRotator.java
new file mode 100644
index 0000000000000000000000000000000000000000..dbf06234fb506b8330a60fbad75de312200e95aa
--- /dev/null
+++ b/core/src/main/java/hudson/matrix/LinkedLogRotator.java
@@ -0,0 +1,37 @@
+package hudson.matrix;
+
+import hudson.model.Job;
+import hudson.tasks.LogRotator;
+
+import java.io.IOException;
+
+/**
+ * {@link LogRotator} for {@link MatrixConfiguration},
+ * which discards the builds if and only if it's discarded
+ * in the parent.
+ *
+ * <p>
+ * Because of the serialization compatibility, we can't easily
+ * refactor {@link LogRotator} into a contract and an implementation. 
+ *
+ * @author Kohsuke Kawaguchi
+ */
+final class LinkedLogRotator extends LogRotator {
+    LinkedLogRotator() {
+        super(-1,-1);
+    }
+
+    @Override
+    public void perform(Job _job) throws IOException {
+        // copy it to the array because we'll be deleting builds as we go.
+        MatrixConfiguration job = (MatrixConfiguration) _job;
+
+        for( MatrixRun r : job.getBuilds().toArray(new MatrixRun[0]) ) {
+            if(job.getParent().getBuildByNumber(r.getNumber())==null)
+                r.delete();
+        }
+
+        if(!job.isActiveConfiguration() && job.getLastBuild()==null)
+            job.delete();
+    }
+}
diff --git a/core/src/main/java/hudson/matrix/MatrixConfiguration.java b/core/src/main/java/hudson/matrix/MatrixConfiguration.java
index 7d94dd50baca09bb4d36c8ea2c450f4181eaab06..d96dd581ef1021bfa61d9698e89ebdb2d258fd29 100644
--- a/core/src/main/java/hudson/matrix/MatrixConfiguration.java
+++ b/core/src/main/java/hudson/matrix/MatrixConfiguration.java
@@ -146,7 +146,7 @@ public class MatrixConfiguration extends Project<MatrixConfiguration,MatrixRun>
 
     @Override
     public LogRotator getLogRotator() {
-        return getParent().getLogRotator();
+        return new LinkedLogRotator();
     }
 
     @Override
@@ -171,4 +171,15 @@ public class MatrixConfiguration extends Project<MatrixConfiguration,MatrixRun>
     public void setLogRotator(LogRotator logRotator) {
         throw new UnsupportedOperationException();
     }
+
+    /**
+     * Returns true if this configuration is a configuration
+     * currently in use today (as opposed to the ones that are
+     * there only to keep the past record.) 
+     *
+     * @see MatrixProject#getActiveConfigurations()
+     */
+    public boolean isActiveConfiguration() {
+        return getParent().getActiveConfigurations().contains(this);
+    }
 }
diff --git a/core/src/main/java/hudson/matrix/MatrixProject.java b/core/src/main/java/hudson/matrix/MatrixProject.java
index b6bd34c5b676cd972b6dd5c97341dc62b02a8a7a..337ecc8898f5aa7e3a39be37bd0f917402310a62 100644
--- a/core/src/main/java/hudson/matrix/MatrixProject.java
+++ b/core/src/main/java/hudson/matrix/MatrixProject.java
@@ -113,6 +113,16 @@ public class MatrixProject extends AbstractProject<MatrixProject,MatrixBuild> im
         rebuildConfigurations();
     }
 
+    public void logRotate() throws IOException {
+        super.logRotate();
+        // perform the log rotation of inactive configurations to make sure
+        // their logs get eventually discarded 
+        for (MatrixConfiguration config : configurations.values()) {
+            if(!config.isActiveConfiguration())
+                config.logRotate();
+        }
+    }
+
     /**
      * Rebuilds the {@link #configurations} list and {@link #activeConfigurations}.
      */
diff --git a/core/src/main/java/hudson/model/AbstractItem.java b/core/src/main/java/hudson/model/AbstractItem.java
index 1b78f06d61632be335f9e20fdf1ae4aa22f2bac0..0b7b67f96af0d034e6aebd7a9db3bbf4eb969a2c 100644
--- a/core/src/main/java/hudson/model/AbstractItem.java
+++ b/core/src/main/java/hudson/model/AbstractItem.java
@@ -163,16 +163,23 @@ public abstract class AbstractItem extends Actionable implements Item {
     /**
      * Deletes this item.
      */
-    public synchronized void doDoDelete( StaplerRequest req, StaplerResponse rsp ) throws IOException {
+    public void doDoDelete( StaplerRequest req, StaplerResponse rsp ) throws IOException {
         if(!Hudson.adminCheck(req,rsp))
             return;
+        delete();
+        rsp.sendRedirect2(req.getContextPath()+"/"+getParent().getUrl());
+    }
+
+    /**
+     * Deletes this item.
+     */
+    public synchronized void delete() throws IOException {
         performDelete();
 
         if(this instanceof TopLevelItem)
             Hudson.getInstance().deleteJob((TopLevelItem)this);
 
         Hudson.getInstance().rebuildDependencyGraph();
-        rsp.sendRedirect2(req.getContextPath()+"/"+getParent().getUrl());
     }
 
     /**
diff --git a/core/src/main/java/hudson/model/Job.java b/core/src/main/java/hudson/model/Job.java
index 75f8fa7068a6c046dec3134504b93976b226d230..d0916033b0837375943ccca9163ee00c4fdef945 100644
--- a/core/src/main/java/hudson/model/Job.java
+++ b/core/src/main/java/hudson/model/Job.java
@@ -175,6 +175,15 @@ public abstract class Job<JobT extends Job<JobT,RunT>, RunT extends Run<JobT,Run
         this.logRotator = logRotator;
     }
 
+    /**
+     * Perform log rotation.
+     */
+    public void logRotate() throws IOException {
+        LogRotator lr = getLogRotator();
+        if(lr!=null)
+            lr.perform(this);
+    }
+
     /**
      * True if this instance supports log rotation configuration.
      */
diff --git a/core/src/main/java/hudson/model/Run.java b/core/src/main/java/hudson/model/Run.java
index e7a58a15b7ed6eb92c966a3ed538f2943987883a..84890dd4a07e0ae48a73bad6216b1a09f60ab616 100644
--- a/core/src/main/java/hudson/model/Run.java
+++ b/core/src/main/java/hudson/model/Run.java
@@ -601,9 +601,7 @@ public abstract class Run <JobT extends Job<JobT,RunT>,RunT extends Run<JobT,Run
             }
 
             try {
-                LogRotator lr = getParent().getLogRotator();
-                if(lr!=null)
-                    lr.perform(getParent());
+                getParent().logRotate();
             } catch (IOException e) {
                 e.printStackTrace();
             }