diff --git a/kernel/file_ops.c b/kernel/file_ops.c
index d2c3ed43..ba0d852f 100644
--- a/kernel/file_ops.c
+++ b/kernel/file_ops.c
@@ -430,6 +430,7 @@ ssize_t hfi1_aio_write(void *private_data, const struct iovec *iovec, unsigned l
 	int done = 0, reqs = 0;
 	kprintf("sizeof(struct hfi1_filedata) = %lu\n", sizeof(struct hfi1_filedata));
 	kprintf("sizeof(struct hfi1_devdata) = %lu\n", sizeof(struct hfi1_devdata));
+	kprintf("sizeof(struct iowait) = %lu\n", sizeof(struct iowait));
 	kprintf("sizeof(struct hfi1_user_sdma_pkt_q) = %lu\n", sizeof(struct hfi1_user_sdma_pkt_q));
 	return 0;
 	hfi1_cdbg(AIOWRITE, "+");
diff --git a/kernel/include/hfi1/ihk_hfi1_common.h b/kernel/include/hfi1/ihk_hfi1_common.h
index 7af8f15e..07ee9b0d 100644
--- a/kernel/include/hfi1/ihk_hfi1_common.h
+++ b/kernel/include/hfi1/ihk_hfi1_common.h
@@ -74,11 +74,12 @@ typedef ihk_spinlock_t spinlock_t;
 #define spin_unlock_irqrestore(lock, flags) do {} while(0)
 #define ____cacheline_aligned_in_smp __attribute__((aligned(64)))
 #define __iomem
-#define spin_lock(...) do {} while(0)
-#define spin_unlock(...) do {} while(0)
+/* double check */
+#define spin_lock ihk_mc_spinlock_lock_noirq
+#define spin_unlock ihk_mc_spinlock_unlock_noirq
+/***********************************************/
 #define smp_wmb() barrier()
 #define smp_rmb() barrier()
-/***********************************************/
 
 #define __rcu
 #define __percpu
diff --git a/kernel/include/hfi1/iowait.h b/kernel/include/hfi1/iowait.h
index a1c79006..3bdefee3 100644
--- a/kernel/include/hfi1/iowait.h
+++ b/kernel/include/hfi1/iowait.h
@@ -90,11 +90,7 @@ struct sdma_engine;
  */
 struct iowait;
 struct iowait_work {
-#ifdef __HFI1_ORIG__
-	struct work_struct iowork;
-#else
-//TODO: iowait_work
-#endif /* __HFI1_ORIG__ */
+	char iowork[32]; // struct work_struct iowork;
 	struct list_head tx_head;
 	struct iowait *iow;
 };
@@ -137,6 +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 */ 
 struct iowait {
 	struct list_head list;
 	int (*sleep)(
@@ -146,13 +143,9 @@ struct iowait {
 		unsigned seq);
 	void (*wakeup)(struct iowait *wait, int reason);
 	void (*sdma_drained)(struct iowait *wait);
-#ifdef __HFI1_ORIG__
 	seqlock_t *lock;
-	wait_queue_head_t wait_dma;
-	wait_queue_head_t wait_pio;
-#else
-//TODO: wait
-#endif /* __HFI1_ORIG__ */
+	char wait_dma[24]; // wait_queue_head_t wait_dma;
+	char wait_pio[24]; // wait_queue_head_t wait_pio;
 	atomic_t sdma_busy;
 	atomic_t pio_busy;
 	u32 count;
diff --git a/kernel/include/hfi1/user_sdma.h b/kernel/include/hfi1/user_sdma.h
index 5f788bee..dd2d3763 100644
--- a/kernel/include/hfi1/user_sdma.h
+++ b/kernel/include/hfi1/user_sdma.h
@@ -113,7 +113,7 @@ extern uint extended_psn;
 #define KDETH_OM_LARGE     64
 #define KDETH_OM_MAX_SIZE  (1 << ((KDETH_OM_LARGE / KDETH_OM_SMALL) + 1))
 
-/* Original size on Linux is 376 Bytes */
+/* The original size on Linux is 376 B */
 struct hfi1_user_sdma_pkt_q {
 	struct list_head list;
 	unsigned ctxt;