diff --git a/kernel/include/hfi1/ihk_hfi1_common.h b/kernel/include/hfi1/ihk_hfi1_common.h
index 07ee9b0d..9b1aad73 100644
--- a/kernel/include/hfi1/ihk_hfi1_common.h
+++ b/kernel/include/hfi1/ihk_hfi1_common.h
@@ -108,6 +108,31 @@ static inline unsigned raw_seqcount_begin(const seqcount_t *s)
 }
 /***********************************************/
 
+/* kernel-xppsl_1.5.2/include/linux/kref.h */
+struct kref {
+	atomic_t refcount;
+};
+
+typedef struct {
+	spinlock_t lock;
+	struct list_head task_list;
+} wait_queue_head_t ;
+
+struct completion {
+	unsigned int done;
+	wait_queue_head_t wait;
+};
+
+/* kernel-xppsl_1.5.2/include/linux/interrupt.h */
+struct tasklet_struct
+{
+	struct tasklet_struct *next;
+	unsigned long state;
+	atomic_t count;
+	void (*func)(unsigned long);
+	unsigned long data;
+};
+
 /* Misc */
 /* From: kernel-xppsl_1.5.2/include/linux/kernel.h */
 #define min_t(type, x, y) ({			\
diff --git a/kernel/include/hfi1/iowait.h b/kernel/include/hfi1/iowait.h
index 3bdefee3..1ac60605 100644
--- a/kernel/include/hfi1/iowait.h
+++ b/kernel/include/hfi1/iowait.h
@@ -133,7 +133,7 @@ struct iowait_work {
  * Waiters explicity know that, but the destroy
  * code that unwaits QPs does not.
  */
-/* The original size on Linux is 240 */ 
+/* The original size on Linux is 240 B */ 
 struct iowait {
 	struct list_head list;
 	int (*sleep)(
diff --git a/kernel/include/hfi1/sdma.h b/kernel/include/hfi1/sdma.h
index 2346b13f..590f8d8f 100644
--- a/kernel/include/hfi1/sdma.h
+++ b/kernel/include/hfi1/sdma.h
@@ -202,7 +202,6 @@ struct sdma_set_state_action {
 	unsigned go_s99_running_totrue:1;
 };
 
-#ifdef __HFI1_ORIG__
 struct sdma_state {
 	struct kref          kref;
 	struct completion    comp;
@@ -214,11 +213,6 @@ struct sdma_state {
 	unsigned             previous_op;
 	enum sdma_events last_event;
 };
-#else
-struct sdma_state {
-	enum sdma_states current_state;	
-};
-#endif /* __HFI1_ORIG__ */
 
 /**
  * DOC: sdma exported routines
@@ -334,6 +328,7 @@ struct hw_sdma_desc {
  * Accessing to non public fields are not supported
  * since the private members are subject to change.
  */
+ /* The original size on Linux is 1472 B */
 struct sdma_engine {
 	/* read mostly */
 	struct hfi1_devdata *dd;
@@ -410,34 +405,29 @@ struct sdma_engine {
 	/* private: */
 	struct list_head      dmawait;
 
-#ifdef __HFI1_ORIG__
 	/* CONFIG SDMA for now, just blindly duplicate */
 	/* private: */
-	struct tasklet_struct sdma_hw_clean_up_task
+	struct tasklet_struct sdma_hw_clean_up_task // size 40
 		____cacheline_aligned_in_smp;
 
 	/* private: */
 	struct tasklet_struct sdma_sw_clean_up_task
 		____cacheline_aligned_in_smp;
 	/* private: */
-	struct work_struct err_halt_worker;
+	char err_halt_worker[32]; // struct work_struct err_halt_worker;
 	/* private */
-	struct timer_list     err_progress_check_timer;
+	char err_progress_check_timer[80]; // struct timer_list     err_progress_check_timer;
 	u32                   progress_check_head;
 	/* private: */
-	struct work_struct flush_worker;
-#endif /* __HFI1_ORIG__ */
+	char flush_worker[32]; // struct work_struct flush_worker;
 	/* protect flush list */
 	spinlock_t flushlist_lock;
 	/* private: */
 	struct list_head flushlist;
-#ifdef __HFI1_ORIG__
-	struct cpumask cpu_mask;
-	struct kobject kobj;
-#endif /* __HFI1_ORIG__ */
+	char cpu_mask[640]; // struct cpusmask cpu_mask;
+	char kobj[64]; // struct kobject kobj
 };
 
-
 #ifdef __HFI1_ORIG__
 
 int sdma_init(struct hfi1_devdata *dd, u8 port);