datapath: Improve comments on struct dp_stats_percpu.

[openvswitch] / datapath / datapath.h

diff --git a/datapath/datapath.h b/datapath/datapath.h
index d28250a128006f259272285ffa0ebd7bf3f71104..c610312b8e79def295f4cafe878e5e5d120a1db8 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
@@ -24,6 +24,7 @@
 /* Mask for the priority bits in a vlan header.  If we ever merge upstream
  * then this should go into include/linux/if_vlan.h. */
 #define VLAN_PCP_MASK 0xe000
+#define VLAN_PCP_SHIFT 13
 
 #define DP_MAX_PORTS 1024
 #define DP_MAX_GROUPS 16
@@ -78,14 +79,30 @@ struct dp_bucket {
        struct sw_flow *flows[];
 };
 
-#define DP_N_QUEUES 2
+#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).
+ * @sflow_pool: Number of packets that were candidates for sFlow sampling,
+ * regardless of whether they were actually chosen and sent down to userspace.
+ */
 struct dp_stats_percpu {
        u64 n_frags;
        u64 n_hit;
        u64 n_missed;
        u64 n_lost;
+       u64 sflow_pool;
 };
 
 struct dp_port_group {
@@ -94,10 +111,29 @@ struct dp_port_group {
        u16 ports[];
 };
 
+/**
+ * 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.
+ * @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.
+ * @n_flows: Number of flows currently in flow table.
+ * @table: Current flow table (RCU protected).
+ * @groups: Port groups, used by ODPAT_OUTPUT_GROUP action (RCU protected).
+ * @n_ports: Number of ports currently in @ports.
+ * @ports: Map from port number to &struct net_bridge_port.  %ODPP_LOCAL port
+ * 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.
+ */
 struct datapath {
        struct mutex mutex;
        int dp_idx;
-
        struct kobject ifobj;
 
        int drop_frags;
@@ -116,10 +152,13 @@ struct datapath {
        /* Switch ports. */
        unsigned int n_ports;
        struct net_bridge_port *ports[DP_MAX_PORTS];
-       struct list_head port_list; /* All ports, including local_port. */
+       struct list_head port_list;
 
        /* Stats. */
        struct dp_stats_percpu *stats_percpu;
+
+       /* sFlow Sampling */
+       unsigned int sflow_probability;
 };
 
 struct net_bridge_port {