diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9fc9464c..f1e10f32 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -19,6 +19,9 @@ jobs:
       # Run the tests
       - name: Dacapo Tests
         run: ./.github/scripts/ci-test-normal.sh
+      - name: Setup tmate session
+        if: ${{ failure() }}
+        uses: mxschmitt/action-tmate@v3
 
       # Run these checks after build
 
diff --git a/jikesrvm/rvm/src/org/jikesrvm/mm/mminterface/MMTkMutatorContext.java b/jikesrvm/rvm/src/org/jikesrvm/mm/mminterface/MMTkMutatorContext.java
index 1a616655..acd41407 100644
--- a/jikesrvm/rvm/src/org/jikesrvm/mm/mminterface/MMTkMutatorContext.java
+++ b/jikesrvm/rvm/src/org/jikesrvm/mm/mminterface/MMTkMutatorContext.java
@@ -139,9 +139,11 @@ public abstract class MMTkMutatorContext extends MutatorContext {
     @Entrypoint
     Address immixAllocator0Context;
     @Entrypoint
-    Address immixAllocator0Hot;
+    byte immixAllocator0Hot;
     @Entrypoint
-    Address immixAllocator0Copy;
+    byte immixAllocator0Copy;
+    byte immixAllocator0Pad0;
+    byte immixAllocator0Pad1;
     @Entrypoint
     Address immixAllocator0LargeCursor;
     @Entrypoint
@@ -253,7 +255,7 @@ public abstract class MMTkMutatorContext extends MutatorContext {
     // Malloc allocator size. We do not need offsets for each field, as we don't need to implement fastpath for large object allocator.
     static final int MALLOC_ALLOCATOR_SIZE = 3 * BYTES_IN_WORD;
     // Immix allocator size
-    static final int IMMIX_ALLOCATOR_SIZE = 12 * BYTES_IN_WORD;
+    static final int IMMIX_ALLOCATOR_SIZE = 11 * BYTES_IN_WORD;
     // Free list allocator size
     static final int FREE_LIST_ALLOCATOR_SIZE = 7 * BYTES_IN_WORD;
     // Mark compact allocator size (the same as bump allocator)
@@ -420,4 +422,9 @@ public void deinitMutator() {
         Address handle = Magic.objectAsAddress(this).plus(MUTATOR_BASE_OFFSET);
         sysCall.sysDestroyMutator(handle);
     }
+
+    @Entrypoint
+    public static final int getInlinedMutatorSize() {
+        return MUTATOR_SIZE;
+    }
 }
\ No newline at end of file
diff --git a/jikesrvm/rvm/src/org/jikesrvm/mm/mminterface/MSContext.java b/jikesrvm/rvm/src/org/jikesrvm/mm/mminterface/MSContext.java
index 692a0288..3a14abef 100644
--- a/jikesrvm/rvm/src/org/jikesrvm/mm/mminterface/MSContext.java
+++ b/jikesrvm/rvm/src/org/jikesrvm/mm/mminterface/MSContext.java
@@ -19,15 +19,15 @@
 @Uninterruptible
 public class MSContext extends MMTkMutatorContext {
     // DEFAULT: FreeListAllocator #0 (MarkSweepSpace)
+    // NonMomving: FreeListAllocator #1 (MarkSweepSpace)
     // CODE: BumpAllocator #0 (ImmortalSpace)
     // LARGECODE: BumpAllocator #1 (ImmortalSpace)
     // Immortal: BumpAllocator #2 (ImmortalSpace)
-    // NonMomving: BumpAllocator #3 (ImmortalSpace)
     // LOS: LargeObjectAllocator #0 (LargeObjectSpace)
 
     @Inline
     protected final int getAllocatorTag(int allocator) {
-        if (allocator == MMTkAllocator.DEFAULT)
+        if (allocator == MMTkAllocator.DEFAULT || allocator == MMTkAllocator.NONMOVING)
             return MMTkMutatorContext.TAG_FREE_LIST;
         else if (allocator == MMTkAllocator.LOS)
             return MMTkMutatorContext.TAG_LARGE_OBJECT;
@@ -37,12 +37,10 @@ else if (allocator == MMTkAllocator.LOS)
     protected final int getAllocatorIndex(int allocator) {
         if (allocator == MMTkAllocator.DEFAULT || allocator == MMTkAllocator.CODE || allocator == MMTkAllocator.LOS) {
             return 0;
-        } else if (allocator == MMTkAllocator.LARGE_CODE) {
+        } else if (allocator == MMTkAllocator.LARGE_CODE || allocator == MMTkAllocator.NONMOVING) {
             return 1;
         } else if (allocator == MMTkAllocator.IMMORTAL) {
             return 2;
-        } else if (allocator == MMTkAllocator.NONMOVING) {
-            return 3;
         } else {
             VM.sysFail("Unexpected allocator", allocator);
             return 0;
@@ -50,7 +48,7 @@ protected final int getAllocatorIndex(int allocator) {
     }
     @Inline
     protected final int getSpaceTag(int allocator) {
-        if (allocator == MMTkAllocator.DEFAULT)
+        if (allocator == MMTkAllocator.DEFAULT || allocator == MMTkAllocator.NONMOVING)
             return MMTkMutatorContext.MARK_SWEEP_SPACE;
         else if (allocator == MMTkAllocator.LOS)
             return MMTkMutatorContext.LARGE_OBJECT_SPACE;
diff --git a/jikesrvm/rvm/src/org/jikesrvm/mm/mminterface/SSContext.java b/jikesrvm/rvm/src/org/jikesrvm/mm/mminterface/SSContext.java
index 9a1365af..8f675129 100644
--- a/jikesrvm/rvm/src/org/jikesrvm/mm/mminterface/SSContext.java
+++ b/jikesrvm/rvm/src/org/jikesrvm/mm/mminterface/SSContext.java
@@ -22,13 +22,15 @@ public class SSContext extends MMTkMutatorContext {
     // CODE: BumpAllocator #1 (ImmortalSpace)
     // LARGE_CODE: BumpAllocator #2 (ImmortalSpace)
     // Immortal: BumpAllocator #3 (ImmortalSpace)
-    // NonMoving: BumpAllocator #4 (ImmortalSpace)
     // LOS: LargeObjectAllocator #0 (LargeObjectSpace)
+    // NonMoving: FreeListAllocator #0 (MarkSweepSpace)
 
     @Inline
     protected final int getAllocatorTag(int allocator) {
         if (allocator == MMTkAllocator.LOS) {
             return MMTkMutatorContext.TAG_LARGE_OBJECT;
+        } else if (allocator == MMTkAllocator.NONMOVING) {
+            return MMTkMutatorContext.TAG_FREE_LIST;
         } else {
             return MMTkMutatorContext.TAG_BUMP_POINTER;
         }
@@ -44,7 +46,7 @@ protected final int getAllocatorIndex(int allocator) {
         } else if (allocator == MMTkAllocator.IMMORTAL) {
             return 3;
         } else if (allocator == MMTkAllocator.NONMOVING) {
-            return 4;
+            return 0;
         } else {
             VM.sysFail("Unexpected allocator", allocator);
             return 0;
@@ -56,6 +58,8 @@ protected final int getSpaceTag(int allocator) {
             return COPY_SPACE;
         } else if (allocator == MMTkAllocator.LOS) {
             return LARGE_OBJECT_SPACE;
+        } else if (allocator == MMTkAllocator.NONMOVING) {
+            return MARK_SWEEP_SPACE;
         } else {
             return IMMORTAL_SPACE;
         }
diff --git a/jikesrvm/rvm/src/org/jikesrvm/runtime/Entrypoints.java b/jikesrvm/rvm/src/org/jikesrvm/runtime/Entrypoints.java
index f02bab40..5a0704a3 100644
--- a/jikesrvm/rvm/src/org/jikesrvm/runtime/Entrypoints.java
+++ b/jikesrvm/rvm/src/org/jikesrvm/runtime/Entrypoints.java
@@ -181,6 +181,9 @@ public class Entrypoints {
   public static final NormalMethod enqueueReferenceMethod =
           getMethod(org.jikesrvm.mm.mminterface.MemoryManager.class, "enqueueReference", "(Lorg/vmmagic/unboxed/Address;)V");
 
+  public static final NormalMethod getInlinedMutatorSizeMethod =
+          getMethod(org.jikesrvm.mm.mminterface.MMTkMutatorContext.class, "getInlinedMutatorSize", "()I");
+
   public static final RVMField numThreadsField =
           getField(org.jikesrvm.scheduler.RVMThread.class, "numThreads", int.class);
   public static final RVMField isCollectorField =
diff --git a/mmtk/Cargo.lock b/mmtk/Cargo.lock
index c7a4a2c0..0d31cdea 100644
--- a/mmtk/Cargo.lock
+++ b/mmtk/Cargo.lock
@@ -424,7 +424,7 @@ dependencies = [
 [[package]]
 name = "mmtk"
 version = "0.24.0"
-source = "git+https://github.com/mmtk/mmtk-core.git?rev=e79e94e744660c486d5471f252ff05c4248bcea9#e79e94e744660c486d5471f252ff05c4248bcea9"
+source = "git+https://github.com/qinsoon/mmtk-core.git?rev=b4424295ebfd146cf45c5b1568524a5c64440093#b4424295ebfd146cf45c5b1568524a5c64440093"
 dependencies = [
  "atomic",
  "atomic-traits",
@@ -459,7 +459,7 @@ dependencies = [
 [[package]]
 name = "mmtk-macros"
 version = "0.24.0"
-source = "git+https://github.com/mmtk/mmtk-core.git?rev=e79e94e744660c486d5471f252ff05c4248bcea9#e79e94e744660c486d5471f252ff05c4248bcea9"
+source = "git+https://github.com/qinsoon/mmtk-core.git?rev=b4424295ebfd146cf45c5b1568524a5c64440093#b4424295ebfd146cf45c5b1568524a5c64440093"
 dependencies = [
  "proc-macro-error",
  "proc-macro2",
@@ -710,9 +710,9 @@ dependencies = [
 
 [[package]]
 name = "sysinfo"
-version = "0.30.10"
+version = "0.30.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "26d7c217777061d5a2d652aea771fb9ba98b6dade657204b08c4b9604d11555b"
+checksum = "87341a165d73787554941cd5ef55ad728011566fe714e987d1b976c15dbc3a83"
 dependencies = [
  "cfg-if",
  "core-foundation-sys",
diff --git a/mmtk/Cargo.toml b/mmtk/Cargo.toml
index 49ce2716..5db41b86 100644
--- a/mmtk/Cargo.toml
+++ b/mmtk/Cargo.toml
@@ -15,8 +15,8 @@ lto = true
 # Metadata for the JikesRVM repository
 [package.metadata.jikesrvm]
 # Our CI matches the following line and extract mmtk/jikesrvm. If this line is updated, please check ci yaml files and make sure it works.
-jikesrvm_repo = "https://github.com/mmtk/jikesrvm.git"
-jikesrvm_version = "a43efe4f33a6a69aabeb03e5c5e2e8880f96f047"
+jikesrvm_repo = "https://github.com/qinsoon/jikesrvm.git"
+jikesrvm_version = "9d04231d8a241e6309d99feea3850d936cc4ec68"
 
 [dependencies]
 libc = "0.2"
@@ -28,7 +28,7 @@ log = {version = "0.4", features = ["max_level_trace", "release_max_level_off"]
 # - change branch/rev
 # - change repo name
 # But other changes including adding/removing whitespaces in commented lines may break the CI.
-mmtk = { git = "https://github.com/mmtk/mmtk-core.git", rev = "e79e94e744660c486d5471f252ff05c4248bcea9" }
+mmtk = { git = "https://github.com/qinsoon/mmtk-core.git", rev = "b4424295ebfd146cf45c5b1568524a5c64440093" }
 # Uncomment the following to build locally - if you change the path locally, do not commit the change in a PR
 # mmtk = { path = "../repos/mmtk-core" }
 
diff --git a/mmtk/src/api.rs b/mmtk/src/api.rs
index d38206f9..fdb1e3f5 100644
--- a/mmtk/src/api.rs
+++ b/mmtk/src/api.rs
@@ -64,7 +64,7 @@ pub extern "C" fn jikesrvm_gc_init(jtoc: *mut c_void, heap_size: usize) {
         builder
             .options
             .vm_space_start
-            .set(unsafe { Address::from_usize(0x6000_0000) });
+            .set(unsafe { Address::from_usize(0x7000_0000) });
         builder.options.vm_space_size.set(0x800_0000);
     }
 
@@ -133,6 +133,14 @@ pub extern "C" fn start_worker(tls: VMWorkerThread, worker: *mut GCWorker<JikesR
 
 #[no_mangle]
 pub extern "C" fn enable_collection(tls: VMThread) {
+    {
+        use crate::entrypoint::*;
+        use std::arch::asm;
+        let java_inlined_mutator_size = unsafe { jtoc_call!(GET_INLINED_MUTATOR_SIZE_METHOD_OFFSET, tls) };
+        let rust_inlined_mutator_size = std::mem::size_of::<mmtk::Mutator<JikesRVM>>();
+        assert_eq!(java_inlined_mutator_size, rust_inlined_mutator_size);
+    }
+
     // MMTk core renamed enable_collection() to initialize_collection(). The JikesRVM binding
     // never uses the new enable_collection() API so we just expose this as enable_collection().
     // Also this is used by JikesRVM for third party heaps in places where it uses JavaMMTK's enableCollection().