The patch set migrates TFRC TX history to a singly-linked list.
The details are:
* use of a consistent naming scheme (all TFRC functions now begin with `tfrc_');
* allocation and cleanup are taken care of internally;
* provision of a lookup function, which is used by the CCID TX infrastructure
to determine the time a packet was sent (in turn used for RTT sampling);
* integration of the new interface with the present use in CCID3.
Signed-off-by: Gerrit Renker <gerrit@xxxxxxxxxxxxxx>
Signed-off-by: Ian McDonald <ian.mcdonald@xxxxxxxxxxx>
---
net/dccp/ccids/ccid3.c | 53 ++++++-------------
net/dccp/ccids/ccid3.h | 3 +-
net/dccp/ccids/lib/packet_history.c | 100 +++++++++++++++++++++++++++++++++-
net/dccp/ccids/lib/packet_history.h | 42 ++++++++++++++-
4 files changed, 155 insertions(+), 43 deletions(-)
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index e07d817..51fd07b 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -49,7 +49,7 @@ static int ccid3_debug;
#define ccid3_pr_debug(format, a...)
#endif
-static struct dccp_tx_hist *ccid3_tx_hist;
+DECLARE_TFRC_TX_CACHE(ccid3_tx_hist);
static struct dccp_rx_hist *ccid3_rx_hist;
/*
@@ -389,29 +389,18 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more,
unsigned int len)
{
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
- struct dccp_tx_hist_entry *packet;
ccid3_hc_tx_update_s(hctx, len);
- packet = dccp_tx_hist_entry_new(ccid3_tx_hist, GFP_ATOMIC);
- if (unlikely(packet == NULL)) {
+ if (tfrc_tx_hist_add(&hctx->ccid3hctx_hist, dccp_sk(sk)->dccps_gss))
DCCP_CRIT("packet history - out of memory!");
- return;
- }
- dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, packet);
-
- packet->dccphtx_tstamp = ktime_get_real();
- packet->dccphtx_seqno = dccp_sk(sk)->dccps_gss;
- packet->dccphtx_rtt = hctx->ccid3hctx_rtt;
- packet->dccphtx_sent = 1;
}
static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
{
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
struct ccid3_options_received *opt_recv;
- struct dccp_tx_hist_entry *packet;
- ktime_t now;
+ ktime_t t_send, now;
unsigned long t_nfb;
u32 pinv, r_sample;
@@ -425,14 +414,12 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
switch (hctx->ccid3hctx_state) {
case TFRC_SSTATE_NO_FBACK:
case TFRC_SSTATE_FBACK:
- /* get packet from history to look up t_recvdata */
- packet = dccp_tx_hist_find_entry(&hctx->ccid3hctx_hist,
- DCCP_SKB_CB(skb)->dccpd_ack_seq);
- if (unlikely(packet == NULL)) {
- DCCP_WARN("%s(%p), seqno %llu(%s) doesn't exist "
- "in history!\n", dccp_role(sk), sk,
- (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq,
- dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));
+ /* estimate RTT from history if ACK number is valid */
+ if (! tfrc_tx_hist_when(&t_send, &hctx->ccid3hctx_hist,
+ DCCP_SKB_CB(skb)->dccpd_ack_seq)) {
+ DCCP_WARN("%s(%p): %s with bogus ACK-%llu\n", dccp_role(sk), sk,
+ dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type),
+ (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq);
return;
}
@@ -451,7 +438,7 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
/*
* Calculate new RTT sample and update moving average
*/
- r_sample = dccp_sample_rtt(sk, ktime_us_delta(now, packet->dccphtx_tstamp));
+ r_sample = dccp_sample_rtt(sk, ktime_us_delta(now, t_send));
hctx->ccid3hctx_rtt = tfrc_ewma(hctx->ccid3hctx_rtt, r_sample, 9);
if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
@@ -493,9 +480,6 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
/* unschedule no feedback timer */
sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
- /* remove all packets older than the one acked from history */
- dccp_tx_hist_purge_older(ccid3_tx_hist,
- &hctx->ccid3hctx_hist, packet);
/*
* As we have calculated new ipi, delta, t_nom it is possible
* that we now can send a packet, so wake up dccp_wait_for_ccid
@@ -598,7 +582,7 @@ static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk)
struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid);
hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT;
- INIT_LIST_HEAD(&hctx->ccid3hctx_hist);
+ tfrc_tx_hist_init(&hctx->ccid3hctx_hist, ccid3_tx_hist);
hctx->ccid3hctx_no_feedback_timer.function =
ccid3_hc_tx_no_feedback_timer;
@@ -616,7 +600,7 @@ static void ccid3_hc_tx_exit(struct sock *sk)
sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
/* Empty packet history */
- dccp_tx_hist_purge(ccid3_tx_hist, &hctx->ccid3hctx_hist);
+ tfrc_tx_hist_cleanup(&hctx->ccid3hctx_hist);
}
static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
@@ -1039,8 +1023,7 @@ static __init int ccid3_module_init(void)
if (ccid3_rx_hist == NULL)
goto out;
- ccid3_tx_hist = dccp_tx_hist_new("ccid3");
- if (ccid3_tx_hist == NULL)
+ if (tfrc_tx_cache_init(&ccid3_tx_hist, "ccid3"))
goto out_free_rx;
rc = ccid_register(&ccid3);
@@ -1050,8 +1033,7 @@ out:
return rc;
out_free_tx:
- dccp_tx_hist_delete(ccid3_tx_hist);
- ccid3_tx_hist = NULL;
+ tfrc_tx_cache_cleanup(ccid3_tx_hist);
out_free_rx:
dccp_rx_hist_delete(ccid3_rx_hist);
ccid3_rx_hist = NULL;
@@ -1063,10 +1045,9 @@ static __exit void ccid3_module_exit(void)
{
ccid_unregister(&ccid3);
- if (ccid3_tx_hist != NULL) {
- dccp_tx_hist_delete(ccid3_tx_hist);
- ccid3_tx_hist = NULL;
- }
+ if (ccid3_tx_hist != NULL)
+ tfrc_tx_cache_cleanup(ccid3_tx_hist);
+
if (ccid3_rx_hist != NULL) {
dccp_rx_hist_delete(ccid3_rx_hist);
ccid3_rx_hist = NULL;
diff --git a/net/dccp/ccids/ccid3.h b/net/dccp/ccids/ccid3.h
index 36eca34..fd363f0 100644
--- a/net/dccp/ccids/ccid3.h
+++ b/net/dccp/ccids/ccid3.h
@@ -40,6 +40,7 @@
#include <linux/list.h>
#include <linux/types.h>
#include <linux/tfrc.h>
+#include "lib/packet_history.h"
#include "../ccid.h"
/* Two seconds as per RFC 3448 4.2 */
@@ -111,7 +112,7 @@ struct ccid3_hc_tx_sock {
ktime_t ccid3hctx_t_ld;
ktime_t ccid3hctx_t_nom;
u32 ccid3hctx_delta;
- struct list_head ccid3hctx_hist;
+ struct tfrc_tx_hist_head ccid3hctx_hist;
struct ccid3_options_received ccid3hctx_options_received;
};
diff --git a/net/dccp/ccids/lib/packet_history.c b/net/dccp/ccids/lib/packet_history.c
index 34c4f60..5651de4 100644
--- a/net/dccp/ccids/lib/packet_history.c
+++ b/net/dccp/ccids/lib/packet_history.c
@@ -1,7 +1,8 @@
/*
* net/dccp/packet_history.c
*
- * Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand.
+ * Copyright (c) 2007 The University of Aberdeen, Scotland, UK
+ * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand.
*
* An implementation of the DCCP protocol
*
@@ -41,6 +42,37 @@
/*
* Transmitter History Routines
*/
+int tfrc_tx_cache_init(struct kmem_cache **cache, const char *name)
+{
+ static const char dccp_tx_hist_mask[] = "tx_hist_%s";
+ char *slab_name;
+
+ slab_name = kmalloc(strlen(name) + sizeof(dccp_tx_hist_mask) - 1,
+ GFP_ATOMIC);
+ if (slab_name == NULL)
+ goto fail;
+
+ sprintf(slab_name, dccp_tx_hist_mask, name);
+ *cache = kmem_cache_create(slab_name, sizeof(struct tfrc_tx_hist),
+ 0, SLAB_HWCACHE_ALIGN, NULL);
+ if (*cache != NULL)
+ return 0;
+
+ kfree(slab_name);
+fail:
+ return -ENOBUFS;
+}
+EXPORT_SYMBOL_GPL(tfrc_tx_cache_init);
+
+void tfrc_tx_cache_cleanup(struct kmem_cache *cache)
+{
+ const char* name = kmem_cache_name(cache);
+
+ kmem_cache_destroy(cache);
+ kfree(name);
+}
+EXPORT_SYMBOL_GPL(tfrc_tx_cache_cleanup);
+
struct dccp_tx_hist *dccp_tx_hist_new(const char *name)
{
struct dccp_tx_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC);
@@ -101,6 +133,69 @@ struct dccp_tx_hist_entry *
EXPORT_SYMBOL_GPL(dccp_tx_hist_find_entry);
+int tfrc_tx_hist_add(struct tfrc_tx_hist_head *head, u64 seqno)
+{
+ struct tfrc_tx_hist *new = kmem_cache_alloc(head->cache, gfp_any());
+
+ if (new == NULL)
+ return -ENOBUFS;
+ new->seqno = seqno;
+ new->stamp = ktime_get_real();
+ new->next = head->first;
+
+ head->first = new;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tfrc_tx_hist_add);
+
+static void tfrc_tx_hist_remove_tail(struct tfrc_tx_hist **pptr,
+ struct kmem_cache *cache)
+{
+ struct tfrc_tx_hist *ptr;
+
+ for (ptr = *pptr; ptr != NULL; ptr = *pptr) {
+ *pptr = ptr->next;
+ kmem_cache_free(cache, ptr);
+ }
+}
+
+void tfrc_tx_hist_cleanup(struct tfrc_tx_hist_head *head)
+{
+ tfrc_tx_hist_remove_tail(&head->first, head->cache);
+}
+EXPORT_SYMBOL_GPL(tfrc_tx_hist_cleanup);
+
+static struct tfrc_tx_hist
+ *tfrc_tx_hist_lookup(struct tfrc_tx_hist_head *head, u64 seqno)
+{
+ struct tfrc_tx_hist *entry;
+
+ for (entry = head->first; entry != NULL; entry = entry->next)
+ if (entry->seqno == seqno)
+ return entry;
+ return NULL;
+}
+
+/**
+ * tfrc_tx_hist_when - Retrieve send time of past packet
+ * @stamp: send time to look up (returns value result)
+ * @head: TX history to search in
+ * @ackno: ACK number which indicates the sent packet's sequence number
+ * If successful, it garbage-collects older (irrelevant) entries and returns 1.
+ */
+int tfrc_tx_hist_when(ktime_t *stamp, struct tfrc_tx_hist_head *head, u64 ackno)
+{
+ struct tfrc_tx_hist *entry = tfrc_tx_hist_lookup(head, ackno);
+
+ if (entry != NULL) {
+ *stamp = entry->stamp;
+ tfrc_tx_hist_remove_tail(&entry->next, head->cache);
+ return 1;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tfrc_tx_hist_when);
+
void dccp_tx_hist_purge(struct dccp_tx_hist *hist, struct list_head *list)
{
struct dccp_tx_hist_entry *entry, *next;
@@ -147,8 +242,7 @@ struct dccp_rx_hist *dccp_rx_hist_new(const char *name)
sprintf(slab_name, dccp_rx_hist_mask, name);
hist->dccprxh_slab = kmem_cache_create(slab_name,
sizeof(struct dccp_rx_hist_entry),
- 0, SLAB_HWCACHE_ALIGN,
- NULL);
+ 0, SLAB_HWCACHE_ALIGN, NULL);
if (hist->dccprxh_slab == NULL)
goto out_free_slab_name;
out:
diff --git a/net/dccp/ccids/lib/packet_history.h b/net/dccp/ccids/lib/packet_history.h
index 032bb61..bb253f1 100644
--- a/net/dccp/ccids/lib/packet_history.h
+++ b/net/dccp/ccids/lib/packet_history.h
@@ -1,10 +1,9 @@
/*
- * net/dccp/packet_history.h
+ * Packet RX/TX history data structures and routines for TFRC-based protocols.
*
+ * Copyright (c) 2007 The University of Aberdeen, Scotland, UK
* Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand.
*
- * An implementation of the DCCP protocol
- *
* This code has been developed by the University of Waikato WAND
* research group. For further information please see http://www.wand.net.nz/
* or e-mail Ian McDonald - ian.mcdonald@xxxxxxxxxxx
@@ -52,6 +51,11 @@
/*
* Transmitter History data structures and declarations
*/
+#define DECLARE_TFRC_TX_CACHE(name) static struct kmem_cache *(name);
+
+extern int tfrc_tx_cache_init(struct kmem_cache **cache, const char *name);
+extern void tfrc_tx_cache_cleanup(struct kmem_cache *cache);
+
struct dccp_tx_hist_entry {
struct list_head dccphtx_node;
u64 dccphtx_seqno:48,
@@ -67,6 +71,35 @@ struct dccp_tx_hist {
extern struct dccp_tx_hist *dccp_tx_hist_new(const char *name);
extern void dccp_tx_hist_delete(struct dccp_tx_hist *hist);
+/**
+ * tfrc_tx_hist - Simple singly-linked TX history list
+ * @next: next oldest entry (LIFO order)
+ * @seqno: sequence number of this entry
+ * @stamp: send time of packet with sequence number @seqno
+ */
+struct tfrc_tx_hist {
+ struct tfrc_tx_hist *next;
+ u64 seqno;
+ ktime_t stamp;
+};
+
+/**
+ * tfrc_tx_hist_head - Head of TX history
+ * @first: begin of the list
+ * @cache: where list entries are allocated from
+ */
+struct tfrc_tx_hist_head {
+ struct tfrc_tx_hist *first;
+ struct kmem_cache *cache;
+};
+
+static inline void tfrc_tx_hist_init(struct tfrc_tx_hist_head *head,
+ struct kmem_cache *cache)
+{
+ head->first = NULL;
+ head->cache = cache;
+}
+
static inline struct dccp_tx_hist_entry *
dccp_tx_hist_entry_new(struct dccp_tx_hist *hist,
const gfp_t prio)
@@ -94,6 +127,9 @@ static inline struct dccp_tx_hist_entry *
extern struct dccp_tx_hist_entry *
dccp_tx_hist_find_entry(const struct list_head *list,
const u64 seq);
+extern int tfrc_tx_hist_add(struct tfrc_tx_hist_head *head, u64 seqno);
+extern int tfrc_tx_hist_when(ktime_t *, struct tfrc_tx_hist_head *, u64);
+extern void tfrc_tx_hist_cleanup(struct tfrc_tx_hist_head *head);
static inline void dccp_tx_hist_add_entry(struct list_head *list,
struct dccp_tx_hist_entry *entry)
--
1.5.2.2.238.g7cbf2f2-dirty
-
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