netdev-linux: Skip miimon execution when disabled

[sliver-openvswitch.git] / lib / netdev-linux.c

diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c
index 80fa39b..7e75144 100644 (file)
--- a/lib/netdev-linux.c
+++ b/lib/netdev-linux.c
@@ -61,6 +61,7 @@
 #include "netlink.h"
 #include "ofpbuf.h"
 #include "openflow/openflow.h"
+#include "ovs-atomic.h"
 #include "packets.h"
 #include "poll-loop.h"
 #include "rtnetlink-link.h"
@@ -402,6 +403,11 @@ struct netdev_rx_linux {
  * additional log messages. */
 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20);
 
+/* Polling miimon status for all ports causes performance degradation when
+ * handling a large number of ports. If there are no devices using miimon, then
+ * we skip netdev_linux_miimon_run() and netdev_linux_miimon_wait(). */
+static atomic_int miimon_cnt = ATOMIC_VAR_INIT(0);
+
 static void netdev_linux_run(void);
 
 static int netdev_linux_do_ethtool(const char *name, struct ethtool_cmd *,
@@ -423,6 +429,7 @@ static int set_etheraddr(const char *netdev_name, const uint8_t[ETH_ADDR_LEN]);
 static int get_stats_via_netlink(int ifindex, struct netdev_stats *stats);
 static int get_stats_via_proc(const char *netdev_name, struct netdev_stats *stats);
 static int af_packet_sock(void);
+static bool netdev_linux_miimon_enabled(void);
 static void netdev_linux_miimon_run(void);
 static void netdev_linux_miimon_wait(void);
 
@@ -485,13 +492,24 @@ netdev_linux_notify_sock(void)
     return sock;
 }
 
+static bool
+netdev_linux_miimon_enabled(void)
+{
+    int miimon;
+
+    atomic_read(&miimon_cnt, &miimon);
+    return miimon > 0;
+}
+
 static void
 netdev_linux_run(void)
 {
     struct nl_sock *sock;
     int error;
 
-    netdev_linux_miimon_run();
+    if (netdev_linux_miimon_enabled()) {
+        netdev_linux_miimon_run();
+    }
 
     sock = netdev_linux_notify_sock();
     if (!sock) {
@@ -553,7 +571,9 @@ netdev_linux_wait(void)
 {
     struct nl_sock *sock;
 
-    netdev_linux_miimon_wait();
+    if (netdev_linux_miimon_enabled()) {
+        netdev_linux_miimon_wait();
+    }
     sock = netdev_linux_notify_sock();
     if (sock) {
         nl_sock_wait(sock, POLLIN);
@@ -711,6 +731,11 @@ netdev_linux_destruct(struct netdev *netdev_)
         close(netdev->tap_fd);
     }
 
+    if (netdev->miimon_interval > 0) {
+        int junk;
+        atomic_sub(&miimon_cnt, 1, &junk);
+    }
+
     ovs_mutex_destroy(&netdev->mutex);
 }
 
@@ -1222,6 +1247,14 @@ netdev_linux_set_miimon_interval(struct netdev *netdev_,
     ovs_mutex_lock(&netdev->mutex);
     interval = interval > 0 ? MAX(interval, 100) : 0;
     if (netdev->miimon_interval != interval) {
+        int junk;
+
+        if (interval && !netdev->miimon_interval) {
+            atomic_add(&miimon_cnt, 1, &junk);
+        } else if (!interval && netdev->miimon_interval) {
+            atomic_sub(&miimon_cnt, 1, &junk);
+        }
+
         netdev->miimon_interval = interval;
         timer_set_expired(&netdev->miimon_timer);
     }
@@ -2100,35 +2133,35 @@ start_queue_dump(const struct netdev *netdev, struct nl_dump *dump)
     return true;
 }
 
+struct netdev_linux_queue_state {
+    unsigned int *queues;
+    size_t cur_queue;
+    size_t n_queues;
+};
+
 static int
-netdev_linux_dump_queues(const struct netdev *netdev_,
-                         netdev_dump_queues_cb *cb, void *aux)
+netdev_linux_queue_dump_start(const struct netdev *netdev_, void **statep)
 {
-    struct netdev_linux *netdev = netdev_linux_cast(netdev_);
+    const struct netdev_linux *netdev = netdev_linux_cast(netdev_);
     int error;
 
     ovs_mutex_lock(&netdev->mutex);
     error = tc_query_qdisc(netdev_);
     if (!error) {
         if (netdev->tc->ops->class_get) {
-            struct tc_queue *queue, *next_queue;
-            struct smap details;
-
-            smap_init(&details);
-            HMAP_FOR_EACH_SAFE (queue, next_queue, hmap_node,
-                                &netdev->tc->queues) {
-                int retval;
-
-                smap_clear(&details);
-
-                retval = netdev->tc->ops->class_get(netdev_, queue, &details);
-                if (!retval) {
-                    (*cb)(queue->queue_id, &details, aux);
-                } else {
-                    error = retval;
-                }
+            struct netdev_linux_queue_state *state;
+            struct tc_queue *queue;
+            size_t i;
+
+            *statep = state = xmalloc(sizeof *state);
+            state->n_queues = hmap_count(&netdev->tc->queues);
+            state->cur_queue = 0;
+            state->queues = xmalloc(state->n_queues * sizeof *state->queues);
+
+            i = 0;
+            HMAP_FOR_EACH (queue, hmap_node, &netdev->tc->queues) {
+                state->queues[i++] = queue->queue_id;
             }
-            smap_destroy(&details);
         } else {
             error = EOPNOTSUPP;
         }
@@ -2138,6 +2171,41 @@ netdev_linux_dump_queues(const struct netdev *netdev_,
     return error;
 }
 
+static int
+netdev_linux_queue_dump_next(const struct netdev *netdev_, void *state_,
+                             unsigned int *queue_idp, struct smap *details)
+{
+    const struct netdev_linux *netdev = netdev_linux_cast(netdev_);
+    struct netdev_linux_queue_state *state = state_;
+    int error = EOF;
+
+    ovs_mutex_lock(&netdev->mutex);
+    while (state->cur_queue < state->n_queues) {
+        unsigned int queue_id = state->queues[state->cur_queue++];
+        struct tc_queue *queue = tc_find_queue(netdev_, queue_id);
+
+        if (queue) {
+            *queue_idp = queue_id;
+            error = netdev->tc->ops->class_get(netdev_, queue, details);
+            break;
+        }
+    }
+    ovs_mutex_unlock(&netdev->mutex);
+
+    return error;
+}
+
+static int
+netdev_linux_queue_dump_done(const struct netdev *netdev OVS_UNUSED,
+                             void *state_)
+{
+    struct netdev_linux_queue_state *state = state_;
+
+    free(state->queues);
+    free(state);
+    return 0;
+}
+
 static int
 netdev_linux_dump_queue_stats(const struct netdev *netdev_,
                               netdev_dump_queue_stats_cb *cb, void *aux)
@@ -2475,6 +2543,9 @@ nd_to_iff_flags(enum netdev_flags nd)
     if (nd & NETDEV_PROMISC) {
         iff |= IFF_PROMISC;
     }
+    if (nd & NETDEV_LOOPBACK) {
+        iff |= IFF_LOOPBACK;
+    }
     return iff;
 }
 
@@ -2488,6 +2559,9 @@ iff_to_nd_flags(int iff)
     if (iff & IFF_PROMISC) {
         nd |= NETDEV_PROMISC;
     }
+    if (iff & IFF_LOOPBACK) {
+        nd |= NETDEV_LOOPBACK;
+    }
     return nd;
 }
 
@@ -2580,7 +2654,9 @@ netdev_linux_change_seq(const struct netdev *netdev_)
     netdev_linux_set_queue,                                     \
     netdev_linux_delete_queue,                                  \
     netdev_linux_get_queue_stats,                               \
-    netdev_linux_dump_queues,                                   \
+    netdev_linux_queue_dump_start,                              \
+    netdev_linux_queue_dump_next,                               \
+    netdev_linux_queue_dump_done,                               \
     netdev_linux_dump_queue_stats,                              \
                                                                 \
     netdev_linux_get_in4,                                       \