[patch 2/5] openmosix/pkt-header-end-mark.patch

Subject: [patch @num@/@total@] @name@

This patch adds a end marker to the kcom_pkt struct so that useless fields are
not anymore sent to the network. That way, the kcom_pkt struct can be extended
to offer precious fields without cost.

---
 hpc/kcom.c         |    8 +++++---
 hpc/kcomd.c        |    2 +-
 include/hpc/kcom.h |   26 +++++++++++++++-----------
 3 files changed, 21 insertions(+), 15 deletions(-)

Index: linux/include/hpc/kcom.h
===================================================================
--- linux.orig/include/hpc/kcom.h	2006-12-19 16:59:13.000000000 +0100
+++ linux/include/hpc/kcom.h	2006-12-22 23:43:19.000000000 +0100
@@ -100,18 +100,22 @@
 
 struct kcom_pkt
 {
-	pid_t hpid;     /* home pid of the this process */
-	pid_t rpid;     /* remote pid of 'that' other node process */
-	int len;      /* len of data */
-	int type;     /* type of data */
-	// int ack;      /* new msg, ack or response */
-	unsigned long addr; /* used by mm pages */
-	unsigned int msgid;
-	struct list_head list;
-	char *data;   /* ptr of data */
-	char *resp;   /* ptr of response */
-};
+	pid_t hpid;     		/* home pid of the this process */
+	pid_t rpid;     		/* remote pid of 'that' other node process */
+	int len;      			/* len of data */
+	int type;     			/* type of data */
+	unsigned long addr; 		/* used by mm pages */
+	unsigned int msgid;		/* each message exchange share the same msgid */
+
+	/* Fields after that point are not sent neither received */
 
+	struct list_head list;		/* This field both marks the end of the "rsendable  */
+					/* And is used for registering the packet in a list */
+
+	char *data;   			/* ptr of data */
+	char *resp;   			/* ptr of response */
+};
+#define KCOM_PKT_NET_SIZE		((size_t)(&((struct kcom_pkt*)0)->list))
 
 struct kcom_node
 {
Index: linux/hpc/kcom.c
===================================================================
--- linux.orig/hpc/kcom.c	2006-12-19 17:00:22.000000000 +0100
+++ linux/hpc/kcom.c	2006-12-22 23:43:19.000000000 +0100
@@ -184,7 +184,7 @@
 	  , (void *) pkt->addr, pkt->msgid);
 
     printk(KERN_DEBUG"[OM] pktdump RAW header dump ----------------------------------------\n");
-    hexdump((char*)pkt, (int) &(((struct kcom_pkt*) 0)->data));
+    hexdump((char*)pkt, KCOM_PKT_NET_SIZE);
     printk(KERN_DEBUG"[OM] pktdump RAW header dump ----------------------------------------\n");
 
 }
@@ -382,8 +382,10 @@
  		return -ENOMEM;
  	}
 
+ 	memset(recv_pkt, 0, sizeof(struct kcom_pkt));
+
 	iov.iov_base = recv_pkt;
- 	iov.iov_len = sizeof(struct kcom_pkt);
+ 	iov.iov_len = KCOM_PKT_NET_SIZE;
 
  	OMDEBUG_PROTOCOL(2, "KCOMD: reading headers ... \n");
 	oldfs = get_fs();
@@ -394,7 +396,7 @@
 
  	i = sock_recvmsg(sock, &msg, iov.iov_len, msg.msg_flags);
  	if ((i == -ENOSPC) || (i == -EAGAIN)) {
- 		if (first_loop && iov.iov_len == sizeof(struct kcom_pkt))
+ 		if (first_loop && iov.iov_len == KCOM_PKT_NET_SIZE)
  			return i;
 
  		/* prevent infinite loop */
Index: linux/hpc/kcomd.c
===================================================================
--- linux.orig/hpc/kcomd.c	2006-12-19 17:00:22.000000000 +0100
+++ linux/hpc/kcomd.c	2006-12-22 23:43:19.000000000 +0100
@@ -195,7 +195,7 @@
 
 
 	packet[0].iov_base = pkt;
-	packet[0].iov_len = sizeof(struct kcom_pkt);
+	packet[0].iov_len = KCOM_PKT_NET_SIZE;
 
 	if (pkt->len) {
 		if(!pkt->data) {