diff -r 5a29bba93a4b -r 04772aca657c src/cpu/o3/commit.hh
--- a/src/cpu/o3/commit.hh	Mon Dec 06 16:01:30 2010 -0800
+++ b/src/cpu/o3/commit.hh	Mon Dec 06 16:05:36 2010 -0800
@@ -406,6 +406,9 @@
     /** The sequence number of the youngest valid instruction in the ROB. */
     InstSeqNum youngestSeqNum[Impl::MaxThreads];
 
+    /** The sequence number of the last commited instruction. */
+    InstSeqNum lastCommitedSeqNum[Impl::MaxThreads];
+
     /** Records if there is a trap currently in flight. */
     bool trapInFlight[Impl::MaxThreads];
 
diff -r 5a29bba93a4b -r 04772aca657c src/cpu/o3/commit_impl.hh
--- a/src/cpu/o3/commit_impl.hh	Mon Dec 06 16:01:30 2010 -0800
+++ b/src/cpu/o3/commit_impl.hh	Mon Dec 06 16:05:36 2010 -0800
@@ -141,6 +141,7 @@
         trapSquash[tid] = false;
         tcSquash[tid] = false;
         pc[tid].set(0);
+        lastCommitedSeqNum[tid] = 0;
     }
 #if FULL_SYSTEM
     interrupt = NoFault;
@@ -498,12 +499,12 @@
     // Hopefully this doesn't mess things up.  Basically I want to squash
     // all instructions of this thread.
     InstSeqNum squashed_inst = rob->isEmpty() ?
-        0 : rob->readHeadInst(tid)->seqNum - 1;
+        lastCommitedSeqNum[tid] : rob->readHeadInst(tid)->seqNum - 1;
 
     // All younger instructions will be squashed. Set the sequence
     // number as the youngest instruction in the ROB (0 in this case.
     // Hopefully nothing breaks.)
-    youngestSeqNum[tid] = 0;
+    youngestSeqNum[tid] = lastCommitedSeqNum[tid];
 
     rob->squash(squashed_inst, tid);
     changedROBNumEntries[tid] = true;
@@ -951,6 +952,9 @@
 
                 TheISA::advancePC(pc[tid], head_inst->staticInst);
 
+                // Keep track of the last sequence number commited
+                lastCommitedSeqNum[tid] = head_inst->seqNum;
+
                 // If this is an instruction that doesn't play nicely with
                 // others squash everything and restart fetch
                 if (head_inst->isSquashAfter())