Enhancements to VNET and to halting:

[palacios.git] / linux_module / palacios-vnet-brg.c

diff --git a/linux_module/palacios-vnet-brg.c b/linux_module/palacios-vnet-brg.c
index 3764a52..309171d 100644 (file)
--- a/linux_module/palacios-vnet-brg.c
+++ b/linux_module/palacios-vnet-brg.c
@@ -19,15 +19,22 @@
 #include <linux/sched.h>
 #include <asm/msr.h>
 
+#include <linux/net.h>
+#include <linux/socket.h>
+#include <net/sock.h>
+
 #include <vnet/vnet.h>
 #include <vnet/vnet_hashtable.h>
 #include "palacios-vnet.h"
 #include "palacios.h"
 
 
+
 #define VNET_SERVER_PORT 9000
 
-#define VNET_YIELD_TIME_USEC 1000
+#define VNET_NOPROGRESS_LIMIT 1000
+
+#define VNET_YIELD_TIME_USEC  1000
 
 struct vnet_link {
     uint32_t dst_ip;
@@ -152,17 +159,26 @@ static uint32_t _create_link(struct vnet_link * link) {
        return -1;
     }
 
+    if (link->sock_proto == UDP) { 
+       // no UDP checksumming
+       lock_sock(link->sock->sk);
+       link->sock->sk->sk_no_check = 1;
+       release_sock(link->sock->sk);
+    }
+
     memset(&link->sock_addr, 0, sizeof(struct sockaddr));
 
     link->sock_addr.sin_family = AF_INET;
     link->sock_addr.sin_addr.s_addr = link->dst_ip;
     link->sock_addr.sin_port = htons(link->dst_port);
 
+
     if ((err = link->sock->ops->connect(link->sock, (struct sockaddr *)&(link->sock_addr), sizeof(struct sockaddr), 0) < 0)) {
        WARNING("Could not connect to remote VNET Server, error %d\n", err);
        return -1;
     }
 
+
     spin_lock_irqsave(&(vnet_brg_s.lock), flags);
     list_add(&(link->node), &(vnet_brg_s.link_list));
     vnet_brg_s.num_links ++;
@@ -237,7 +253,7 @@ _udp_send(struct socket * sock,
     iov.iov_base = buf;
     iov.iov_len = len;
 
-    msg.msg_flags = 0;
+    msg.msg_flags = MSG_NOSIGNAL;
     msg.msg_name = addr;
     msg.msg_namelen = sizeof(struct sockaddr_in);
     msg.msg_control = NULL;
@@ -384,6 +400,13 @@ static int init_vnet_serv(void) {
        return -1;
     }
 
+    if (vnet_brg_s.serv_proto == UDP) { 
+       // No UDP checksumming is done
+       lock_sock(vnet_brg_s.serv_sock->sk);
+       vnet_brg_s.serv_sock->sk->sk_no_check = 1;
+       release_sock(vnet_brg_s.serv_sock->sk);
+    }
+
     memset(&vnet_brg_s.serv_addr, 0, sizeof(struct sockaddr));
 
     vnet_brg_s.serv_addr.sin_family = AF_INET;
@@ -404,6 +427,8 @@ static int init_vnet_serv(void) {
        }
     }
 
+
+
     return 0;
 }
 
@@ -412,6 +437,7 @@ static int _udp_server(void * arg) {
     struct sockaddr_in pkt_addr;
     struct vnet_link * link = NULL;
     int len;
+    uint64_t noprogress_count;
 
     INFO("Palacios VNET Bridge: UDP receiving server ..... \n");
 
@@ -422,6 +448,8 @@ static int _udp_server(void * arg) {
        return -1;
     }
 
+    
+    noprogress_count=0;
 
     while (!kthread_should_stop()) {
 
@@ -436,10 +464,32 @@ static int _udp_server(void * arg) {
        // If it would have blocked, we have no packet, and so
        // we will give other threads on this core a chance
        if (len==-EAGAIN || len==-EWOULDBLOCK || len==-EINTR) { 
-           palacios_yield_cpu_timed(VNET_YIELD_TIME_USEC);
+
+           // avoid rollover in the counter out of paranoia
+           if (! ((noprogress_count + 1) < noprogress_count)) { 
+               noprogress_count++;
+           }
+           
+           // adaptively select yielding strategy depending on
+           // whether we are making progress
+           if (noprogress_count < VNET_NOPROGRESS_LIMIT) { 
+               // Likely making progress, do fast yield so we 
+               // come back immediately if there is no other action
+               palacios_yield_cpu();
+           } else {
+               // Likely not making progress, do potentially slow
+               // yield - we won't come back for until VNET_YIELD_TIME_USEC has passed
+               palacios_yield_cpu_timed(VNET_YIELD_TIME_USEC);
+           }
+
            continue;
        }
        
+
+       // Something interesting has happened, therefore progress!
+       noprogress_count=0;
+           
+
        if(len < 0) {
            WARNING("Receive error: Could not get packet, error %d\n", len);
            continue;