rxrpc: Add per-peer RTT tracker
Add a function to track the average RTT for a peer. Sources of RTT data
will be added in subsequent patches.
The RTT data will be useful in the future for determining resend timeouts
and for handling the slow-start part of the Rx protocol.
Also add a pair of tracepoints, one to log transmissions to elicit a
response for RTT purposes and one to log responses that contribute RTT
data.
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index dcf54e3..79c671e 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -258,10 +258,11 @@
/* calculated RTT cache */
#define RXRPC_RTT_CACHE_SIZE 32
- suseconds_t rtt; /* current RTT estimate (in uS) */
- unsigned int rtt_point; /* next entry at which to insert */
- unsigned int rtt_usage; /* amount of cache actually used */
- suseconds_t rtt_cache[RXRPC_RTT_CACHE_SIZE]; /* calculated RTT cache */
+ u64 rtt; /* Current RTT estimate (in nS) */
+ u64 rtt_sum; /* Sum of cache contents */
+ u64 rtt_cache[RXRPC_RTT_CACHE_SIZE]; /* Determined RTT cache */
+ u8 rtt_cursor; /* next entry at which to insert */
+ u8 rtt_usage; /* amount of cache actually used */
};
/*
@@ -657,6 +658,20 @@
extern const char rxrpc_recvmsg_traces[rxrpc_recvmsg__nr_trace][5];
+enum rxrpc_rtt_tx_trace {
+ rxrpc_rtt_tx_ping,
+ rxrpc_rtt_tx__nr_trace
+};
+
+extern const char rxrpc_rtt_tx_traces[rxrpc_rtt_tx__nr_trace][5];
+
+enum rxrpc_rtt_rx_trace {
+ rxrpc_rtt_rx_ping_response,
+ rxrpc_rtt_rx__nr_trace
+};
+
+extern const char rxrpc_rtt_rx_traces[rxrpc_rtt_rx__nr_trace][5];
+
extern const char *const rxrpc_pkts[];
extern const char *rxrpc_acks(u8 reason);
@@ -955,6 +970,8 @@
*/
void rxrpc_error_report(struct sock *);
void rxrpc_peer_error_distributor(struct work_struct *);
+void rxrpc_peer_add_rtt(struct rxrpc_call *, enum rxrpc_rtt_rx_trace,
+ rxrpc_serial_t, rxrpc_serial_t, ktime_t, ktime_t);
/*
* peer_object.c