diff --git a/drivers/net/mmnif.c b/drivers/net/mmnif.c
index ba491915..3ba716c9 100644
--- a/drivers/net/mmnif.c
+++ b/drivers/net/mmnif.c
@@ -48,6 +48,7 @@ extern HANDLE hProc;
 #define DEBUGPRINTF(x,...)  kprintf(x,##__VA_ARGS__)
 
 #include <metalsvm/semaphore.h>
+#include <metalsvm/spinlock.h>
 
 #include <asm/RCCE_lib.h>
 #include <asm/RCCE.h>
@@ -186,7 +187,8 @@ typedef struct mm_rx_buffer
 
 	uint8_t			iv_intr;
 
-	sem_t			lock;
+//	sem_t			lock;
+        spinlock_t              lock;
 
 //	uint32_t		timestamp[MMNIF_RX_QUEUELEN];
 //	uint32_t		bitmap[MMNIF_RX_QUEUELEN];
@@ -543,7 +545,8 @@ __inline void mmnif_lock_rx_hdr(int dest_ip)
 #else
 	if(disable_locking) return;
 	mm_rx_buffer_t* hdr = (char*)mpb_start_address + ( dest_ip -1 ) * mpb_size;
-	sem_wait(&hdr->lock);
+//	sem_wait(&hdr->lock);
+        spinlock_lock(&hdr->lock);
 #endif
 }
 /* mmnif_unlock_rx_hdr(): unlock the header
@@ -559,7 +562,7 @@ __inline void mmnif_unlock_rx_hdr(int dest_ip)
 #else
 	if(disable_locking) return;
 	mm_rx_buffer_t* hdr = (char*)mpb_start_address + ( dest_ip -1 ) * mpb_size;
-	sem_post(&hdr->lock);
+        spinlock_unlock(&hdr->lock);
 #endif
 }
 
@@ -874,7 +877,8 @@ err_t mmnif_init(struct netif* netif)
 
 	/* init the lock for the hdr
 	 */
-	sem_init(&mmnif->rx_buff->lock,1);
+//	sem_init(&mmnif->rx_buff->lock,1);
+        spinlock_init(&mmnif->rx_buff->lock);
 
 	/* init the sems for communication art
 	 */
@@ -1188,6 +1192,7 @@ int mmnif_poll(void* e)
 	{
 		while (!mmnif->rx_buff->queued)
 		{
+                        mmnif->stats.pll_empty++;
 			if (mmnif->stats.pll_empty >= MMNIF_POLL_BUDGET)
 			{
 			/*   enable interrupts and suspend polling
@@ -1200,11 +1205,9 @@ int mmnif_poll(void* e)
 				DEBUGPRINTF("mmnif_poll(): heuristical interrupts enabled\n");
 #endif
 				sem_wait(&mmnif->com_poll);
-				mmnif->stats.pll_empty = 1;
-			}
-                        mmnif->stats.pll_empty++;
+			}     
 		}
-		mmnif->stats.pll_empty--;
+                mmnif->stats.pll_empty=0;
 		mmnif_rx(mmnif_dev);
 
 		if (instant_process)