net/colo-compare.c: Optimize compare order for performance

COLO-compare use the glib function g_queue_find_custom to dump
another VM's networking packet to compare. But this function always
start find from the queue->head(here is the newest packet), It will
reduce the success rate of comparison. So this patch reversed
the order of the queues for performance.

Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Reported-by: leirao <lei.rao@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

net/colo-compare.c

@@ -197,7 +197,7 @@ static void colo_compare_inconsistency_notify(CompareState *s)
 /* Use restricted to colo_insert_packet() */
 static gint seq_sorter(Packet *a, Packet *b, gpointer data)
 {
-    return a->tcp_seq - b->tcp_seq;
+    return b->tcp_seq - a->tcp_seq;
 }
 
 static void fill_pkt_tcp_info(void *data, uint32_t *max_ack)
@@ -421,13 +421,13 @@ static void colo_compare_tcp(CompareState *s, Connection *conn)
     if (g_queue_is_empty(&conn->primary_list)) {
         return;
     }
-    ppkt = g_queue_pop_head(&conn->primary_list);
+    ppkt = g_queue_pop_tail(&conn->primary_list);
 sec:
     if (g_queue_is_empty(&conn->secondary_list)) {
-        g_queue_push_head(&conn->primary_list, ppkt);
+        g_queue_push_tail(&conn->primary_list, ppkt);
         return;
     }
-    spkt = g_queue_pop_head(&conn->secondary_list);
+    spkt = g_queue_pop_tail(&conn->secondary_list);
 
     if (ppkt->tcp_seq == ppkt->seq_end) {
         colo_release_primary_pkt(s, ppkt);
@@ -458,7 +458,7 @@ static void colo_compare_tcp(CompareState *s, Connection *conn)
             }
         }
         if (!ppkt) {
-            g_queue_push_head(&conn->secondary_list, spkt);
+            g_queue_push_tail(&conn->secondary_list, spkt);
             goto pri;
         }
     }
@@ -477,7 +477,7 @@ static void colo_compare_tcp(CompareState *s, Connection *conn)
         if (mark == COLO_COMPARE_FREE_PRIMARY) {
             conn->compare_seq = ppkt->seq_end;
             colo_release_primary_pkt(s, ppkt);
-            g_queue_push_head(&conn->secondary_list, spkt);
+            g_queue_push_tail(&conn->secondary_list, spkt);
             goto pri;
         } else if (mark == COLO_COMPARE_FREE_SECONDARY) {
             conn->compare_seq = spkt->seq_end;
@@ -490,8 +490,8 @@ static void colo_compare_tcp(CompareState *s, Connection *conn)
             goto pri;
         }
     } else {
-        g_queue_push_head(&conn->primary_list, ppkt);
-        g_queue_push_head(&conn->secondary_list, spkt);
+        g_queue_push_tail(&conn->primary_list, ppkt);
+        g_queue_push_tail(&conn->secondary_list, spkt);
 
 #ifdef DEBUG_COLO_PACKETS
         qemu_hexdump(stderr, "colo-compare ppkt", ppkt->data, ppkt->size);
@@ -673,7 +673,7 @@ static void colo_compare_packet(CompareState *s, Connection *conn,
 
     while (!g_queue_is_empty(&conn->primary_list) &&
            !g_queue_is_empty(&conn->secondary_list)) {
-        pkt = g_queue_pop_head(&conn->primary_list);
+        pkt = g_queue_pop_tail(&conn->primary_list);
         result = g_queue_find_custom(&conn->secondary_list,
                  pkt, (GCompareFunc)HandlePacket);
 
@@ -689,7 +689,7 @@ static void colo_compare_packet(CompareState *s, Connection *conn,
              * timeout, it will trigger a checkpoint request.
              */
             trace_colo_compare_main("packet different");
-            g_queue_push_head(&conn->primary_list, pkt);
+            g_queue_push_tail(&conn->primary_list, pkt);
 
             colo_compare_inconsistency_notify(s);
             break;
@@ -819,7 +819,7 @@ static int compare_chr_send(CompareState *s,
         entry->buf = g_malloc(size);
         memcpy(entry->buf, buf, size);
     }
-    g_queue_push_head(&sendco->send_list, entry);
+    g_queue_push_tail(&sendco->send_list, entry);
 
     if (sendco->done) {
         sendco->co = qemu_coroutine_create(_compare_chr_send, sendco);
@@ -1347,7 +1347,7 @@ static void colo_flush_packets(void *opaque, void *user_data)
     Packet *pkt = NULL;
 
     while (!g_queue_is_empty(&conn->primary_list)) {
-        pkt = g_queue_pop_head(&conn->primary_list);
+        pkt = g_queue_pop_tail(&conn->primary_list);
         compare_chr_send(s,
                          pkt->data,
                          pkt->size,
@@ -1357,7 +1357,7 @@ static void colo_flush_packets(void *opaque, void *user_data)
         packet_destroy_partial(pkt, NULL);
     }
     while (!g_queue_is_empty(&conn->secondary_list)) {
-        pkt = g_queue_pop_head(&conn->secondary_list);
+        pkt = g_queue_pop_tail(&conn->secondary_list);
         packet_destroy(pkt, NULL);
     }
 }