Commit 276f2edc authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo Committed by David S. Miller
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[TFRC]: Migrate TX history to singly-linked lis



This patch was based on another made by Gerrit Renker, his changelog was:

    ------------------------------------------------------
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.
    ------------------------------------------------------

Simplifications I did:

. removing the tfrc_tx_hist_head that had a pointer to the list head and
  another for the slabcache.
. No need for creating a slabcache for each CCID that wants to use the TFRC
  tx history routines, create a single slabcache when the dccp_tfrc_lib module
  init routine is called.
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ea4f76ae
......@@ -49,7 +49,6 @@ static int ccid3_debug;
#define ccid3_pr_debug(format, a...)
#endif
static struct dccp_tx_hist *ccid3_tx_hist;
static struct dccp_rx_hist *ccid3_rx_hist;
/*
......@@ -389,28 +388,18 @@ 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;
struct tfrc_tx_hist_entry *packet;
ktime_t now;
unsigned long t_nfb;
u32 pinv, r_sample;
......@@ -425,16 +414,19 @@ 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 */
packet = tfrc_tx_hist_find_entry(hctx->ccid3hctx_hist,
DCCP_SKB_CB(skb)->dccpd_ack_seq);
if (packet == NULL) {
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;
}
/*
* Garbage-collect older (irrelevant) entries
*/
tfrc_tx_hist_purge(&packet->next);
/* Update receive rate in units of 64 * bytes/second */
hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate;
......@@ -451,7 +443,7 @@ 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, packet->stamp));
hctx->ccid3hctx_rtt = tfrc_ewma(hctx->ccid3hctx_rtt, r_sample, 9);
if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
......@@ -493,9 +485,6 @@ 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 +587,7 @@ 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);
hctx->ccid3hctx_hist = NULL;
setup_timer(&hctx->ccid3hctx_no_feedback_timer,
ccid3_hc_tx_no_feedback_timer, (unsigned long)sk);
......@@ -612,8 +601,7 @@ static void ccid3_hc_tx_exit(struct sock *sk)
ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM);
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_purge(&hctx->ccid3hctx_hist);
}
static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
......@@ -1036,19 +1024,12 @@ 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)
goto out_free_rx;
rc = ccid_register(&ccid3);
if (rc != 0)
goto out_free_tx;
goto out_free_rx;
out:
return rc;
out_free_tx:
dccp_tx_hist_delete(ccid3_tx_hist);
ccid3_tx_hist = NULL;
out_free_rx:
dccp_rx_hist_delete(ccid3_rx_hist);
ccid3_rx_hist = NULL;
......@@ -1060,10 +1041,6 @@ 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_rx_hist != NULL) {
dccp_rx_hist_delete(ccid3_rx_hist);
ccid3_rx_hist = NULL;
......
......@@ -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_entry *ccid3hctx_hist;
struct ccid3_options_received ccid3hctx_options_received;
};
......
......@@ -277,7 +277,7 @@ void dccp_li_update_li(struct sock *sk,
EXPORT_SYMBOL_GPL(dccp_li_update_li);
static __init int dccp_li_init(void)
int __init dccp_li_init(void)
{
dccp_li_cachep = kmem_cache_create("dccp_li_hist",
sizeof(struct dccp_li_hist_entry),
......@@ -285,10 +285,10 @@ static __init int dccp_li_init(void)
return dccp_li_cachep == NULL ? -ENOBUFS : 0;
}
static __exit void dccp_li_exit(void)
void dccp_li_exit(void)
{
kmem_cache_destroy(dccp_li_cachep);
if (dccp_li_cachep != NULL) {
kmem_cache_destroy(dccp_li_cachep);
dccp_li_cachep = NULL;
}
}
module_init(dccp_li_init);
module_exit(dccp_li_exit);
/*
* 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
*
......@@ -39,93 +40,48 @@
#include "packet_history.h"
/*
* Transmitter History Routines
* Transmitter History Routines
*/
struct dccp_tx_hist *dccp_tx_hist_new(const char *name)
{
struct dccp_tx_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC);
static const char dccp_tx_hist_mask[] = "tx_hist_%s";
char *slab_name;
static struct kmem_cache *tfrc_tx_hist;
if (hist == NULL)
goto out;
slab_name = kmalloc(strlen(name) + sizeof(dccp_tx_hist_mask) - 1,
GFP_ATOMIC);
if (slab_name == NULL)
goto out_free_hist;
sprintf(slab_name, dccp_tx_hist_mask, name);
hist->dccptxh_slab = kmem_cache_create(slab_name,
sizeof(struct dccp_tx_hist_entry),
0, SLAB_HWCACHE_ALIGN,
NULL);
if (hist->dccptxh_slab == NULL)
goto out_free_slab_name;
out:
return hist;
out_free_slab_name:
kfree(slab_name);
out_free_hist:
kfree(hist);
hist = NULL;
goto out;
}
EXPORT_SYMBOL_GPL(dccp_tx_hist_new);
void dccp_tx_hist_delete(struct dccp_tx_hist *hist)
struct tfrc_tx_hist_entry *
tfrc_tx_hist_find_entry(struct tfrc_tx_hist_entry *head, u64 seqno)
{
const char* name = kmem_cache_name(hist->dccptxh_slab);
while (head != NULL && head->seqno != seqno)
head = head->next;
kmem_cache_destroy(hist->dccptxh_slab);
kfree(name);
kfree(hist);
return head;
}
EXPORT_SYMBOL_GPL(tfrc_tx_hist_find_entry);
EXPORT_SYMBOL_GPL(dccp_tx_hist_delete);
struct dccp_tx_hist_entry *
dccp_tx_hist_find_entry(const struct list_head *list, const u64 seq)
int tfrc_tx_hist_add(struct tfrc_tx_hist_entry **headp, u64 seqno)
{
struct dccp_tx_hist_entry *packet = NULL, *entry;
list_for_each_entry(entry, list, dccphtx_node)
if (entry->dccphtx_seqno == seq) {
packet = entry;
break;
}
return packet;
struct tfrc_tx_hist_entry *entry = kmem_cache_alloc(tfrc_tx_hist, gfp_any());
if (entry == NULL)
return -ENOBUFS;
entry->seqno = seqno;
entry->stamp = ktime_get_real();
entry->next = *headp;
*headp = entry;
return 0;
}
EXPORT_SYMBOL_GPL(tfrc_tx_hist_add);
EXPORT_SYMBOL_GPL(dccp_tx_hist_find_entry);
void dccp_tx_hist_purge(struct dccp_tx_hist *hist, struct list_head *list)
void tfrc_tx_hist_purge(struct tfrc_tx_hist_entry **headp)
{
struct dccp_tx_hist_entry *entry, *next;
struct tfrc_tx_hist_entry *head = *headp;
list_for_each_entry_safe(entry, next, list, dccphtx_node) {
list_del_init(&entry->dccphtx_node);
dccp_tx_hist_entry_delete(hist, entry);
}
}
EXPORT_SYMBOL_GPL(dccp_tx_hist_purge);
while (head != NULL) {
struct tfrc_tx_hist_entry *next = head->next;
void dccp_tx_hist_purge_older(struct dccp_tx_hist *hist,
struct list_head *list,
struct dccp_tx_hist_entry *packet)
{
struct dccp_tx_hist_entry *next;
list_for_each_entry_safe_continue(packet, next, list, dccphtx_node) {
list_del_init(&packet->dccphtx_node);
dccp_tx_hist_entry_delete(hist, packet);
kmem_cache_free(tfrc_tx_hist, head);
head = next;
}
}
EXPORT_SYMBOL_GPL(dccp_tx_hist_purge_older);
*headp = NULL;
}
EXPORT_SYMBOL_GPL(tfrc_tx_hist_purge);
/*
* Receiver History Routines
......@@ -147,8 +103,7 @@ 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:
......@@ -293,6 +248,37 @@ void dccp_rx_hist_purge(struct dccp_rx_hist *hist, struct list_head *list)
EXPORT_SYMBOL_GPL(dccp_rx_hist_purge);
extern int __init dccp_li_init(void);
extern void dccp_li_exit(void);
static __init int packet_history_init(void)
{
if (dccp_li_init() != 0)
goto out;
tfrc_tx_hist = kmem_cache_create("tfrc_tx_hist",
sizeof(struct tfrc_tx_hist_entry), 0,
SLAB_HWCACHE_ALIGN, NULL);
if (tfrc_tx_hist == NULL)
goto out_li_exit;
return 0;
out_li_exit:
dccp_li_exit();
out:
return -ENOBUFS;
}
module_init(packet_history_init);
static __exit void packet_history_exit(void)
{
if (tfrc_tx_hist != NULL) {
kmem_cache_destroy(tfrc_tx_hist);
tfrc_tx_hist = NULL;
}
dccp_li_exit();
}
module_exit(packet_history_exit);
MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, "
"Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
......
/*
* 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@jandi.co.nz
......@@ -49,71 +48,23 @@
#define TFRC_WIN_COUNT_PER_RTT 4
#define TFRC_WIN_COUNT_LIMIT 16
/*
* Transmitter History data structures and declarations
/**
* tfrc_tx_hist_entry - 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 dccp_tx_hist_entry {
struct list_head dccphtx_node;
u64 dccphtx_seqno:48,
dccphtx_sent:1;
u32 dccphtx_rtt;
ktime_t dccphtx_tstamp;
};
struct dccp_tx_hist {
struct kmem_cache *dccptxh_slab;
struct tfrc_tx_hist_entry {
struct tfrc_tx_hist_entry *next;
u64 seqno;
ktime_t stamp;
};
extern struct dccp_tx_hist *dccp_tx_hist_new(const char *name);
extern void dccp_tx_hist_delete(struct dccp_tx_hist *hist);
static inline struct dccp_tx_hist_entry *
dccp_tx_hist_entry_new(struct dccp_tx_hist *hist,
const gfp_t prio)
{
struct dccp_tx_hist_entry *entry = kmem_cache_alloc(hist->dccptxh_slab,
prio);
if (entry != NULL)
entry->dccphtx_sent = 0;
return entry;
}
static inline struct dccp_tx_hist_entry *
dccp_tx_hist_head(struct list_head *list)
{
struct dccp_tx_hist_entry *head = NULL;
if (!list_empty(list))
head = list_entry(list->next, struct dccp_tx_hist_entry,
dccphtx_node);
return head;
}
extern struct dccp_tx_hist_entry *
dccp_tx_hist_find_entry(const struct list_head *list,
const u64 seq);
static inline void dccp_tx_hist_add_entry(struct list_head *list,
struct dccp_tx_hist_entry *entry)
{
list_add(&entry->dccphtx_node, list);
}
static inline void dccp_tx_hist_entry_delete(struct dccp_tx_hist *hist,
struct dccp_tx_hist_entry *entry)
{
if (entry != NULL)
kmem_cache_free(hist->dccptxh_slab, entry);
}
extern void dccp_tx_hist_purge(struct dccp_tx_hist *hist,
struct list_head *list);
extern int tfrc_tx_hist_add(struct tfrc_tx_hist_entry **headp, u64 seqno);
extern void tfrc_tx_hist_purge(struct tfrc_tx_hist_entry **headp);
extern void dccp_tx_hist_purge_older(struct dccp_tx_hist *hist,
struct list_head *list,
struct dccp_tx_hist_entry *next);
extern struct tfrc_tx_hist_entry *
tfrc_tx_hist_find_entry(struct tfrc_tx_hist_entry *head, u64 ackno);
/*
* Receiver History data structures and declarations
......
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