sflow: Fix sFlow sampling structure.

[sliver-openvswitch.git] / datapath / datapath.h

diff --git a/datapath/datapath.h b/datapath/datapath.h
index 929b9d8..d98a965 100644 (file)
--- a/datapath/datapath.h
+++ b/datapath/datapath.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009 Nicira Networks.
+ * Copyright (c) 2009, 2010 Nicira Networks.
  * Distributed under the terms of the GNU GPL version 2.
  *
  * Significant portions of this file may be copied from parts of the Linux
@@ -82,12 +82,24 @@ struct dp_bucket {
 #define DP_N_QUEUES 3
 #define DP_MAX_QUEUE_LEN 100
 
+/**
+ * struct dp_stats_percpu - per-cpu packet processing statistics for a given
+ * datapath.
+ * @n_frags: Number of IP fragments processed by datapath.
+ * @n_hit: Number of received packets for which a matching flow was found in
+ * the flow table.
+ * @n_miss: Number of received packets that had no matching flow in the flow
+ * table.  The sum of @n_hit and @n_miss is the number of packets that have
+ * been received by the datapath.
+ * @n_lost: Number of received packets that had no matching flow in the flow
+ * table that could not be sent to userspace (normally due to an overflow in
+ * one of the datapath's queues).
+ */
 struct dp_stats_percpu {
        u64 n_frags;
        u64 n_hit;
        u64 n_missed;
        u64 n_lost;
-       u64 sflow_pool;         /* Packets that could have been sampled. */
 };
 
 struct dp_port_group {
@@ -100,7 +112,7 @@ struct dp_port_group {
  * struct datapath - datapath for flow-based packet switching
  * @mutex: Mutual exclusion for ioctls.
  * @dp_idx: Datapath number (index into the dps[] array in datapath.c).
- * @ifobj: &struct kobject representing the datapath.
+ * @ifobj: Represents /sys/class/net/<devname>/brif.
  * @drop_frags: Drop all IP fragments if nonzero.
  * @queues: %DP_N_QUEUES sets of queued packets for userspace to handle.
  * @waitqueue: Waitqueue, for waiting for new packets in @queues.
@@ -112,9 +124,9 @@ struct dp_port_group {
  * always exists, other ports may be %NULL.
  * @port_list: List of all ports in @ports in arbitrary order.
  * @stats_percpu: Per-CPU datapath statistics.
- * @sflow_probability: Probability of sampling a packet to the %ODPL_SFLOW
- * queue, where 0 means never sample, UINT_MAX means always sample, and
- * other values are intermediate probabilities.
+ * @sflow_probability: Number of packets out of UINT_MAX to sample to the
+ * %ODPL_SFLOW queue, e.g. (@sflow_probability/UINT_MAX) is the probability of
+ * sampling a given packet.
  */
 struct datapath {
        struct mutex mutex;
@@ -146,13 +158,28 @@ struct datapath {
        unsigned int sflow_probability;
 };
 
+/**
+ * struct net_bridge_port - one port within a datapath
+ * @port_no: Index into @dp's @ports array.
+ * @dp: Datapath to which this port belongs.
+ * @dev: The network device attached to this port.  The @br_port member in @dev
+ * points back to this &struct net_bridge_port.
+ * @kobj: Represents /sys/class/net/<devname>/brport.
+ * @linkname: The name of the link from /sys/class/net/<datapath>/brif to this
+ * &struct net_bridge_port.  (We keep this around so that we can delete it
+ * if @dev gets renamed.)  Set to the null string when no link exists.
+ * @node: Element in @dp's @port_list.
+ * @sflow_pool: Number of packets that were candidates for sFlow sampling,
+ * regardless of whether they were actually chosen and sent down to userspace.
+ */
 struct net_bridge_port {
        u16 port_no;
        struct datapath *dp;
        struct net_device *dev;
        struct kobject kobj;
        char linkname[IFNAMSIZ];
-       struct list_head node;   /* Element in datapath.ports. */
+       struct list_head node;
+       atomic_t sflow_pool;
 };
 
 extern struct notifier_block dp_device_notifier;