rxrpc: Use ktimes for call timeout tracking and set the timer lazily

Track the call timeouts as ktimes rather than jiffies as the latter's
granularity is too high and only set the timer at the end of the event
handling function.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

1 files changed, 18 insertions, 18 deletions

diff --git a/net/rxrpc/rtt.c b/net/rxrpc/rtt.c
index be61d6f5be8d..cdab7b7d08a0 100644
--- a/net/rxrpc/rtt.c
+++ b/net/rxrpc/rtt.c
@@ -11,8 +11,8 @@
 #include <linux/net.h>
 #include "ar-internal.h"
 
-#define RXRPC_RTO_MAX	((unsigned)(120 * HZ))
-#define RXRPC_TIMEOUT_INIT ((unsigned)(1*HZ))	/* RFC6298 2.1 initial RTO value	*/
+#define RXRPC_RTO_MAX	(120 * USEC_PER_SEC)
+#define RXRPC_TIMEOUT_INIT ((unsigned int)(1 * MSEC_PER_SEC)) /* RFC6298 2.1 initial RTO value */
 #define rxrpc_jiffies32 ((u32)jiffies)		/* As rxrpc_jiffies32 */
 
 static u32 rxrpc_rto_min_us(struct rxrpc_peer *peer)
@@ -22,7 +22,7 @@ static u32 rxrpc_rto_min_us(struct rxrpc_peer *peer)
 
 static u32 __rxrpc_set_rto(const struct rxrpc_peer *peer)
 {
-	return usecs_to_jiffies((peer->srtt_us >> 3) + peer->rttvar_us);
+	return (peer->srtt_us >> 3) + peer->rttvar_us;
 }
 
 static u32 rxrpc_bound_rto(u32 rto)
@@ -124,7 +124,7 @@ static void rxrpc_set_rto(struct rxrpc_peer *peer)
 	/* NOTE: clamping at RXRPC_RTO_MIN is not required, current algo
 	 * guarantees that rto is higher.
 	 */
-	peer->rto_j = rxrpc_bound_rto(rto);
+	peer->rto_us = rxrpc_bound_rto(rto);
 }
 
 static void rxrpc_ack_update_rtt(struct rxrpc_peer *peer, long rtt_us)
@@ -163,33 +163,33 @@ void rxrpc_peer_add_rtt(struct rxrpc_call *call, enum rxrpc_rtt_rx_trace why,
 	spin_unlock(&peer->rtt_input_lock);
 
 	trace_rxrpc_rtt_rx(call, why, rtt_slot, send_serial, resp_serial,
-			   peer->srtt_us >> 3, peer->rto_j);
+			   peer->srtt_us >> 3, peer->rto_us);
 }
 
 /*
- * Get the retransmission timeout to set in jiffies, backing it off each time
- * we retransmit.
+ * Get the retransmission timeout to set in nanoseconds, backing it off each
+ * time we retransmit.
  */
-unsigned long rxrpc_get_rto_backoff(struct rxrpc_peer *peer, bool retrans)
+ktime_t rxrpc_get_rto_backoff(struct rxrpc_peer *peer, bool retrans)
 {
-	u64 timo_j;
-	u8 backoff = READ_ONCE(peer->backoff);
+	u64 timo_us;
+	u32 backoff = READ_ONCE(peer->backoff);
 
-	timo_j = peer->rto_j;
-	timo_j <<= backoff;
-	if (retrans && timo_j * 2 <= RXRPC_RTO_MAX)
+	timo_us = peer->rto_us;
+	timo_us <<= backoff;
+	if (retrans && timo_us * 2 <= RXRPC_RTO_MAX)
 		WRITE_ONCE(peer->backoff, backoff + 1);
 
-	if (timo_j < 1)
-		timo_j = 1;
+	if (timo_us < 1)
+		timo_us = 1;
 
-	return timo_j;
+	return ns_to_ktime(timo_us * NSEC_PER_USEC);
 }
 
 void rxrpc_peer_init_rtt(struct rxrpc_peer *peer)
 {
-	peer->rto_j	= RXRPC_TIMEOUT_INIT;
-	peer->mdev_us	= jiffies_to_usecs(RXRPC_TIMEOUT_INIT);
+	peer->rto_us	= RXRPC_TIMEOUT_INIT;
+	peer->mdev_us	= RXRPC_TIMEOUT_INIT;
 	peer->backoff	= 0;
 	//minmax_reset(&peer->rtt_min, rxrpc_jiffies32, ~0U);
 }