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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

net/dccp/ccids/ccid3.c

+17 −40
Original line number Diff line number Diff line
@@ -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,

		/* 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 (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));

		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;

net/dccp/ccids/ccid3.h

+2 −1
Original line number Diff line number Diff line
@@ -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;

};

net/dccp/ccids/lib/loss_interval.c

+6 −6
Original line number Diff line number Diff line
@@ -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)

{

	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/ccids/lib/packet_history.c

+62 −76
Original line number Diff line number Diff line 
/*

 *  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

 *
@@ -41,91 +42,46 @@ 
/*

 * 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/ccids/lib/packet_history.h

+15 −64
Original line number Diff line number Diff line 
/*

 *  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