[PATCH net-next 2/9] rxrpc: Add re-sent Tx annotation [ver #2]

2016-09-22 Thread David Howells 
Add a Tx-phase annotation for packet buffers to indicate that a buffer has
already been retransmitted.  This will be used by future congestion
management.  Re-retransmissions of a packet don't affect the congestion
window managment in the same way as initial retransmissions.

Signed-off-by: David Howells 
---

 net/rxrpc/ar-internal.h |2 ++
 net/rxrpc/call_event.c  |   28 +++-
 net/rxrpc/input.c   |   14 +++---
 3 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index f021df4a6a22..dcf54e3fb478 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -505,6 +505,8 @@ struct rxrpc_call {
 #define RXRPC_TX_ANNO_UNACK1
 #define RXRPC_TX_ANNO_NAK  2
 #define RXRPC_TX_ANNO_RETRANS  3
+#define RXRPC_TX_ANNO_MASK 0x03
+#define RXRPC_TX_ANNO_RESENT   0x04
 #define RXRPC_RX_ANNO_JUMBO0x3f/* Jumbo subpacket number + 1 
if not zero */
 #define RXRPC_RX_ANNO_JLAST0x40/* Set if last element of a 
jumbo packet */
 #define RXRPC_RX_ANNO_VERIFIED 0x80/* Set if verified and 
decrypted */
diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
index 6247ce25eb21..34ad967f2d81 100644
--- a/net/rxrpc/call_event.c
+++ b/net/rxrpc/call_event.c
@@ -144,7 +144,7 @@ static void rxrpc_resend(struct rxrpc_call *call)
rxrpc_seq_t cursor, seq, top;
unsigned long resend_at, now;
int ix;
-   u8 annotation;
+   u8 annotation, anno_type;
 
_enter("{%d,%d}", call->tx_hard_ack, call->tx_top);
 
@@ -165,14 +165,16 @@ static void rxrpc_resend(struct rxrpc_call *call)
for (seq = cursor + 1; before_eq(seq, top); seq++) {
ix = seq & RXRPC_RXTX_BUFF_MASK;
annotation = call->rxtx_annotations[ix];
-   if (annotation == RXRPC_TX_ANNO_ACK)
+   anno_type = annotation & RXRPC_TX_ANNO_MASK;
+   annotation &= ~RXRPC_TX_ANNO_MASK;
+   if (anno_type == RXRPC_TX_ANNO_ACK)
continue;
 
skb = call->rxtx_buffer[ix];
rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
sp = rxrpc_skb(skb);
 
-   if (annotation == RXRPC_TX_ANNO_UNACK) {
+   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;
@@ -181,7 +183,7 @@ static void rxrpc_resend(struct rxrpc_call *call)
}
 
/* Okay, we need to retransmit a packet. */
-   call->rxtx_annotations[ix] = RXRPC_TX_ANNO_RETRANS;
+   call->rxtx_annotations[ix] = RXRPC_TX_ANNO_RETRANS | annotation;
}
 
call->resend_at = resend_at;
@@ -194,7 +196,8 @@ static void rxrpc_resend(struct rxrpc_call *call)
for (seq = cursor + 1; before_eq(seq, top); seq++) {
ix = seq & RXRPC_RXTX_BUFF_MASK;
annotation = call->rxtx_annotations[ix];
-   if (annotation != RXRPC_TX_ANNO_RETRANS)
+   anno_type = annotation & RXRPC_TX_ANNO_MASK;
+   if (anno_type != RXRPC_TX_ANNO_RETRANS)
continue;
 
skb = call->rxtx_buffer[ix];
@@ -220,10 +223,17 @@ static void rxrpc_resend(struct rxrpc_call *call)
 * received and the packet might have been hard-ACK'd (in which
 * case it will no longer be in the buffer).
 */
-   if (after(seq, call->tx_hard_ack) &&
-   (call->rxtx_annotations[ix] == RXRPC_TX_ANNO_RETRANS ||
-call->rxtx_annotations[ix] == RXRPC_TX_ANNO_NAK))
-   call->rxtx_annotations[ix] = RXRPC_TX_ANNO_UNACK;
+   if (after(seq, call->tx_hard_ack)) {
+   annotation = call->rxtx_annotations[ix];
+   anno_type = annotation & RXRPC_TX_ANNO_MASK;
+   if (anno_type == RXRPC_TX_ANNO_RETRANS ||
+   anno_type == RXRPC_TX_ANNO_NAK) {
+   annotation &= ~RXRPC_TX_ANNO_MASK;
+   annotation |= RXRPC_TX_ANNO_UNACK;
+   }
+   annotation |= RXRPC_TX_ANNO_RESENT;
+   call->rxtx_annotations[ix] = annotation;
+   }
 
if (after(call->tx_hard_ack, seq))
seq = call->tx_hard_ack;
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 7ac1edf3aac7..aa261df9fc9e 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -388,17 +388,25 @@ static void rxrpc_input_soft_acks(struct rxrpc_call 
*call, u8 *acks,
 {
bool resend = false;
int ix;
+   u8 annotation, anno_type;
 
for (; nr_acks > 0; nr_acks--, seq++)

[PATCH net-next 2/9] rxrpc: Add re-sent Tx annotation [ver #2]

2016-09-22 Thread David Howells 
Add a Tx-phase annotation for packet buffers to indicate that a buffer has
already been retransmitted.  This will be used by future congestion
management.  Re-retransmissions of a packet don't affect the congestion
window managment in the same way as initial retransmissions.

Signed-off-by: David Howells 
---

 net/rxrpc/ar-internal.h |2 ++
 net/rxrpc/call_event.c  |   28 +++-
 net/rxrpc/input.c   |   14 +++---
 3 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index f021df4a6a22..dcf54e3fb478 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -505,6 +505,8 @@ struct rxrpc_call {
 #define RXRPC_TX_ANNO_UNACK1
 #define RXRPC_TX_ANNO_NAK  2
 #define RXRPC_TX_ANNO_RETRANS  3
+#define RXRPC_TX_ANNO_MASK 0x03
+#define RXRPC_TX_ANNO_RESENT   0x04
 #define RXRPC_RX_ANNO_JUMBO0x3f/* Jumbo subpacket number + 1 
if not zero */
 #define RXRPC_RX_ANNO_JLAST0x40/* Set if last element of a 
jumbo packet */
 #define RXRPC_RX_ANNO_VERIFIED 0x80/* Set if verified and 
decrypted */
diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
index 6247ce25eb21..34ad967f2d81 100644
--- a/net/rxrpc/call_event.c
+++ b/net/rxrpc/call_event.c
@@ -144,7 +144,7 @@ static void rxrpc_resend(struct rxrpc_call *call)
rxrpc_seq_t cursor, seq, top;
unsigned long resend_at, now;
int ix;
-   u8 annotation;
+   u8 annotation, anno_type;
 
_enter("{%d,%d}", call->tx_hard_ack, call->tx_top);
 
@@ -165,14 +165,16 @@ static void rxrpc_resend(struct rxrpc_call *call)
for (seq = cursor + 1; before_eq(seq, top); seq++) {
ix = seq & RXRPC_RXTX_BUFF_MASK;
annotation = call->rxtx_annotations[ix];
-   if (annotation == RXRPC_TX_ANNO_ACK)
+   anno_type = annotation & RXRPC_TX_ANNO_MASK;
+   annotation &= ~RXRPC_TX_ANNO_MASK;
+   if (anno_type == RXRPC_TX_ANNO_ACK)
continue;
 
skb = call->rxtx_buffer[ix];
rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
sp = rxrpc_skb(skb);
 
-   if (annotation == RXRPC_TX_ANNO_UNACK) {
+   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;
@@ -181,7 +183,7 @@ static void rxrpc_resend(struct rxrpc_call *call)
}
 
/* Okay, we need to retransmit a packet. */
-   call->rxtx_annotations[ix] = RXRPC_TX_ANNO_RETRANS;
+   call->rxtx_annotations[ix] = RXRPC_TX_ANNO_RETRANS | annotation;
}
 
call->resend_at = resend_at;
@@ -194,7 +196,8 @@ static void rxrpc_resend(struct rxrpc_call *call)
for (seq = cursor + 1; before_eq(seq, top); seq++) {
ix = seq & RXRPC_RXTX_BUFF_MASK;
annotation = call->rxtx_annotations[ix];
-   if (annotation != RXRPC_TX_ANNO_RETRANS)
+   anno_type = annotation & RXRPC_TX_ANNO_MASK;
+   if (anno_type != RXRPC_TX_ANNO_RETRANS)
continue;
 
skb = call->rxtx_buffer[ix];
@@ -220,10 +223,17 @@ static void rxrpc_resend(struct rxrpc_call *call)
 * received and the packet might have been hard-ACK'd (in which
 * case it will no longer be in the buffer).
 */
-   if (after(seq, call->tx_hard_ack) &&
-   (call->rxtx_annotations[ix] == RXRPC_TX_ANNO_RETRANS ||
-call->rxtx_annotations[ix] == RXRPC_TX_ANNO_NAK))
-   call->rxtx_annotations[ix] = RXRPC_TX_ANNO_UNACK;
+   if (after(seq, call->tx_hard_ack)) {
+   annotation = call->rxtx_annotations[ix];
+   anno_type = annotation & RXRPC_TX_ANNO_MASK;
+   if (anno_type == RXRPC_TX_ANNO_RETRANS ||
+   anno_type == RXRPC_TX_ANNO_NAK) {
+   annotation &= ~RXRPC_TX_ANNO_MASK;
+   annotation |= RXRPC_TX_ANNO_UNACK;
+   }
+   annotation |= RXRPC_TX_ANNO_RESENT;
+   call->rxtx_annotations[ix] = annotation;
+   }
 
if (after(call->tx_hard_ack, seq))
seq = call->tx_hard_ack;
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 7ac1edf3aac7..aa261df9fc9e 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -388,17 +388,25 @@ static void rxrpc_input_soft_acks(struct rxrpc_call 
*call, u8 *acks,
 {
bool resend = false;
int ix;
+   u8 annotation, anno_type;
 
for (; nr_acks > 0; nr_acks--, seq++) {
ix