[PATCH net-next 7/9] rxrpc: Obtain RTT data by requesting ACKs on DATA packets [ver #2]
In addition to sending a PING ACK to gain RTT data, we can set the
RXRPC_REQUEST_ACK flag on a DATA packet and get a REQUESTED-ACK ACK. The
ACK packet contains the serial number of the packet it is in response to,
so we can look through the Tx buffer for a matching DATA packet.
This requires that the data packets be stamped with the time of
transmission as a ktime rather than having the resend_at time in jiffies.
This further requires the resend code to do the resend determination in
ktimes and convert to jiffies to set the timer.
Signed-off-by: David Howells
---
net/rxrpc/ar-internal.h |7 +++
net/rxrpc/call_event.c | 19 +--
net/rxrpc/input.c | 35 +++
net/rxrpc/misc.c|6 --
net/rxrpc/output.c |7 +--
net/rxrpc/sendmsg.c |1 -
net/rxrpc/sysctl.c |2 +-
7 files changed, 57 insertions(+), 20 deletions(-)
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 8b47f468eb9d..1c4597b2c6cd 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -142,10 +142,7 @@ struct rxrpc_host_header {
*/
struct rxrpc_skb_priv {
union {
- unsigned long resend_at; /* time in jiffies at which to
resend */
- struct {
- u8 nr_jumbo; /* Number of jumbo subpackets */
- };
+ u8 nr_jumbo; /* Number of jumbo subpackets */
};
union {
unsigned intoffset; /* offset into buffer of next
read */
@@ -663,6 +660,7 @@ extern const char
rxrpc_recvmsg_traces[rxrpc_recvmsg__nr_trace][5];
enum rxrpc_rtt_tx_trace {
rxrpc_rtt_tx_ping,
+ rxrpc_rtt_tx_data,
rxrpc_rtt_tx__nr_trace
};
@@ -670,6 +668,7 @@ 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_requested_ack,
rxrpc_rtt_rx__nr_trace
};
diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
index 34ad967f2d81..adb2ec61e21f 100644
--- a/net/rxrpc/call_event.c
+++ b/net/rxrpc/call_event.c
@@ -142,12 +142,14 @@ static void rxrpc_resend(struct rxrpc_call *call)
struct rxrpc_skb_priv *sp;
struct sk_buff *skb;
rxrpc_seq_t cursor, seq, top;
- unsigned long resend_at, now;
+ ktime_t now = ktime_get_real(), max_age, oldest, resend_at;
int ix;
u8 annotation, anno_type;
_enter("{%d,%d}", call->tx_hard_ack, call->tx_top);
+ max_age = ktime_sub_ms(now, rxrpc_resend_timeout);
+
spin_lock_bh(&call->lock);
cursor = call->tx_hard_ack;
@@ -160,8 +162,7 @@ static void rxrpc_resend(struct rxrpc_call *call)
* the packets in the Tx buffer we're going to resend and what the new
* resend timeout will be.
*/
- now = jiffies;
- resend_at = now + rxrpc_resend_timeout;
+ oldest = now;
for (seq = cursor + 1; before_eq(seq, top); seq++) {
ix = seq & RXRPC_RXTX_BUFF_MASK;
annotation = call->rxtx_annotations[ix];
@@ -175,9 +176,9 @@ static void rxrpc_resend(struct rxrpc_call *call)
sp = rxrpc_skb(skb);
if (anno_type == RXRPC_TX_ANNO_UNACK) {
- if (time_after(sp->resend_at, now)) {
- if (time_before(sp->resend_at, resend_at))
- resend_at = sp->resend_at;
+ if (ktime_after(skb->tstamp, max_age)) {
+ if (ktime_before(skb->tstamp, oldest))
+ oldest = skb->tstamp;
continue;
}
}
@@ -186,7 +187,8 @@ static void rxrpc_resend(struct rxrpc_call *call)
call->rxtx_annotations[ix] = RXRPC_TX_ANNO_RETRANS | annotation;
}
- call->resend_at = resend_at;
+ resend_at = ktime_sub(ktime_add_ns(oldest, rxrpc_resend_timeout), now);
+ call->resend_at = jiffies + nsecs_to_jiffies(ktime_to_ns(resend_at));
/* Now go through the Tx window and perform the retransmissions. We
* have to drop the lock for each send. If an ACK comes in whilst the
@@ -205,15 +207,12 @@ static void rxrpc_resend(struct rxrpc_call *call)
spin_unlock_bh(&call->lock);
if (rxrpc_send_data_packet(call, skb) < 0) {
- call->resend_at = now + 2;
rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
return;
}
if (rxrpc_is_client_call(call))
rxrpc_expose_client_call(call);
- sp = rxrpc_skb(skb);
- sp->resend_at = now + rxrpc_resend_timeout;
rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
spin_lock_bh(&call->lock)
[PATCH net-next 7/9] rxrpc: Obtain RTT data by requesting ACKs on DATA packets
In addition to sending a PING ACK to gain RTT data, we can set the
RXRPC_REQUEST_ACK flag on a DATA packet and get a REQUESTED-ACK ACK. The
ACK packet contains the serial number of the packet it is in response to,
so we can look through the Tx buffer for a matching DATA packet.
This requires that the data packets be stamped with the time of
transmission as a ktime rather than having the resend_at time in jiffies.
This further requires the resend code to do the resend determination in
ktimes and convert to jiffies to set the timer.
Signed-off-by: David Howells
---
net/rxrpc/ar-internal.h |7 +++
net/rxrpc/call_event.c | 20 ++--
net/rxrpc/input.c | 35 +++
net/rxrpc/misc.c|6 --
net/rxrpc/output.c |7 +--
net/rxrpc/sendmsg.c |1 -
net/rxrpc/sysctl.c |2 +-
7 files changed, 58 insertions(+), 20 deletions(-)
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 8b47f468eb9d..1c4597b2c6cd 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -142,10 +142,7 @@ struct rxrpc_host_header {
*/
struct rxrpc_skb_priv {
union {
- unsigned long resend_at; /* time in jiffies at which to
resend */
- struct {
- u8 nr_jumbo; /* Number of jumbo subpackets */
- };
+ u8 nr_jumbo; /* Number of jumbo subpackets */
};
union {
unsigned intoffset; /* offset into buffer of next
read */
@@ -663,6 +660,7 @@ extern const char
rxrpc_recvmsg_traces[rxrpc_recvmsg__nr_trace][5];
enum rxrpc_rtt_tx_trace {
rxrpc_rtt_tx_ping,
+ rxrpc_rtt_tx_data,
rxrpc_rtt_tx__nr_trace
};
@@ -670,6 +668,7 @@ 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_requested_ack,
rxrpc_rtt_rx__nr_trace
};
diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
index 34ad967f2d81..77802da14456 100644
--- a/net/rxrpc/call_event.c
+++ b/net/rxrpc/call_event.c
@@ -142,12 +142,14 @@ static void rxrpc_resend(struct rxrpc_call *call)
struct rxrpc_skb_priv *sp;
struct sk_buff *skb;
rxrpc_seq_t cursor, seq, top;
- unsigned long resend_at, now;
+ ktime_t now = ktime_get_real(), max_age, oldest, resend_at;
int ix;
u8 annotation, anno_type;
_enter("{%d,%d}", call->tx_hard_ack, call->tx_top);
+ max_age = ktime_sub_ms(now, rxrpc_resend_timeout);
+
spin_lock_bh(&call->lock);
cursor = call->tx_hard_ack;
@@ -160,8 +162,7 @@ static void rxrpc_resend(struct rxrpc_call *call)
* the packets in the Tx buffer we're going to resend and what the new
* resend timeout will be.
*/
- now = jiffies;
- resend_at = now + rxrpc_resend_timeout;
+ oldest = now;
for (seq = cursor + 1; before_eq(seq, top); seq++) {
ix = seq & RXRPC_RXTX_BUFF_MASK;
annotation = call->rxtx_annotations[ix];
@@ -175,9 +176,9 @@ static void rxrpc_resend(struct rxrpc_call *call)
sp = rxrpc_skb(skb);
if (anno_type == RXRPC_TX_ANNO_UNACK) {
- if (time_after(sp->resend_at, now)) {
- if (time_before(sp->resend_at, resend_at))
- resend_at = sp->resend_at;
+ if (ktime_after(skb->tstamp, max_age)) {
+ if (ktime_before(skb->tstamp, oldest))
+ oldest = skb->tstamp;
continue;
}
}
@@ -186,7 +187,9 @@ static void rxrpc_resend(struct rxrpc_call *call)
call->rxtx_annotations[ix] = RXRPC_TX_ANNO_RETRANS | annotation;
}
- call->resend_at = resend_at;
+ resend_at = ktime_sub(ktime_add_ns(oldest, rxrpc_resend_timeout), now);
+ call->resend_at = jiffies +
+ usecs_to_jiffies(ktime_to_ns(resend_at) / NSEC_PER_USEC);
/* Now go through the Tx window and perform the retransmissions. We
* have to drop the lock for each send. If an ACK comes in whilst the
@@ -205,15 +208,12 @@ static void rxrpc_resend(struct rxrpc_call *call)
spin_unlock_bh(&call->lock);
if (rxrpc_send_data_packet(call, skb) < 0) {
- call->resend_at = now + 2;
rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
return;
}
if (rxrpc_is_client_call(call))
rxrpc_expose_client_call(call);
- sp = rxrpc_skb(skb);
- sp->resend_at = now + rxrpc_resend_timeout;
rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
