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[TFRC]: Remove previous loss intervals implementation
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Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Gerrit Renker authored and David S. Miller committed Jan 28, 2008
1 parent 954c2db commit 3f71c81
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Showing 2 changed files with 1 addition and 275 deletions.
266 changes: 0 additions & 266 deletions net/dccp/ccids/lib/loss_interval.c
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Original file line number Diff line number Diff line change
Expand Up @@ -14,15 +14,6 @@
#include <net/sock.h>
#include "tfrc.h"

#define DCCP_LI_HIST_IVAL_F_LENGTH 8

struct dccp_li_hist_entry {
struct list_head dccplih_node;
u64 dccplih_seqno:48,
dccplih_win_count:4;
u32 dccplih_interval;
};

static struct kmem_cache *tfrc_lh_slab __read_mostly;
/* Loss Interval weights from [RFC 3448, 5.4], scaled by 10 */
static const int tfrc_lh_weights[NINTERVAL] = { 10, 10, 10, 10, 8, 6, 4, 2 };
Expand Down Expand Up @@ -71,77 +62,6 @@ void tfrc_lh_cleanup(struct tfrc_loss_hist *lh)
}
EXPORT_SYMBOL_GPL(tfrc_lh_cleanup);

static struct kmem_cache *dccp_li_cachep __read_mostly;

static inline struct dccp_li_hist_entry *dccp_li_hist_entry_new(const gfp_t prio)
{
return kmem_cache_alloc(dccp_li_cachep, prio);
}

static inline void dccp_li_hist_entry_delete(struct dccp_li_hist_entry *entry)
{
if (entry != NULL)
kmem_cache_free(dccp_li_cachep, entry);
}

void dccp_li_hist_purge(struct list_head *list)
{
struct dccp_li_hist_entry *entry, *next;

list_for_each_entry_safe(entry, next, list, dccplih_node) {
list_del_init(&entry->dccplih_node);
kmem_cache_free(dccp_li_cachep, entry);
}
}

EXPORT_SYMBOL_GPL(dccp_li_hist_purge);

/* Weights used to calculate loss event rate */
/*
* These are integers as per section 8 of RFC3448. We can then divide by 4 *
* when we use it.
*/
static const int dccp_li_hist_w[DCCP_LI_HIST_IVAL_F_LENGTH] = {
4, 4, 4, 4, 3, 2, 1, 1,
};

u32 dccp_li_hist_calc_i_mean(struct list_head *list)
{
struct dccp_li_hist_entry *li_entry, *li_next;
int i = 0;
u32 i_tot;
u32 i_tot0 = 0;
u32 i_tot1 = 0;
u32 w_tot = 0;

list_for_each_entry_safe(li_entry, li_next, list, dccplih_node) {
if (li_entry->dccplih_interval != ~0U) {
i_tot0 += li_entry->dccplih_interval * dccp_li_hist_w[i];
w_tot += dccp_li_hist_w[i];
if (i != 0)
i_tot1 += li_entry->dccplih_interval * dccp_li_hist_w[i - 1];
}


if (++i > DCCP_LI_HIST_IVAL_F_LENGTH)
break;
}

if (i != DCCP_LI_HIST_IVAL_F_LENGTH)
return 0;

i_tot = max(i_tot0, i_tot1);

if (!w_tot) {
DCCP_WARN("w_tot = 0\n");
return 1;
}

return i_tot / w_tot;
}

EXPORT_SYMBOL_GPL(dccp_li_hist_calc_i_mean);

static void tfrc_lh_calc_i_mean(struct tfrc_loss_hist *lh)
{
u32 i_i, i_tot0 = 0, i_tot1 = 0, w_tot = 0;
Expand Down Expand Up @@ -201,192 +121,6 @@ u8 tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *skb)
}
EXPORT_SYMBOL_GPL(tfrc_lh_update_i_mean);

static int dccp_li_hist_interval_new(struct list_head *list,
const u64 seq_loss, const u8 win_loss)
{
struct dccp_li_hist_entry *entry;
int i;

for (i = 0; i < DCCP_LI_HIST_IVAL_F_LENGTH; i++) {
entry = dccp_li_hist_entry_new(GFP_ATOMIC);
if (entry == NULL) {
dccp_li_hist_purge(list);
DCCP_BUG("loss interval list entry is NULL");
return 0;
}
entry->dccplih_interval = ~0;
list_add(&entry->dccplih_node, list);
}

entry->dccplih_seqno = seq_loss;
entry->dccplih_win_count = win_loss;
return 1;
}

/* calculate first loss interval
*
* returns estimated loss interval in usecs */
static u32 dccp_li_calc_first_li(struct sock *sk,
struct list_head *hist_list,
ktime_t last_feedback,
u16 s, u32 bytes_recv,
u32 previous_x_recv)
{
/*
* FIXME:
* Will be rewritten in the upcoming new loss intervals code.
* Has to be commented ou because it relies on the old rx history
* data structures
*/
#if 0
struct tfrc_rx_hist_entry *entry, *next, *tail = NULL;
u32 x_recv, p;
suseconds_t rtt, delta;
ktime_t tstamp = ktime_set(0, 0);
int interval = 0;
int win_count = 0;
int step = 0;
u64 fval;

list_for_each_entry_safe(entry, next, hist_list, tfrchrx_node) {
if (tfrc_rx_hist_entry_data_packet(entry)) {
tail = entry;

switch (step) {
case 0:
tstamp = entry->tfrchrx_tstamp;
win_count = entry->tfrchrx_ccval;
step = 1;
break;
case 1:
interval = win_count - entry->tfrchrx_ccval;
if (interval < 0)
interval += TFRC_WIN_COUNT_LIMIT;
if (interval > 4)
goto found;
break;
}
}
}

if (unlikely(step == 0)) {
DCCP_WARN("%s(%p), packet history has no data packets!\n",
dccp_role(sk), sk);
return ~0;
}

if (unlikely(interval == 0)) {
DCCP_WARN("%s(%p), Could not find a win_count interval > 0. "
"Defaulting to 1\n", dccp_role(sk), sk);
interval = 1;
}
found:
if (!tail) {
DCCP_CRIT("tail is null\n");
return ~0;
}

delta = ktime_us_delta(tstamp, tail->tfrchrx_tstamp);
DCCP_BUG_ON(delta < 0);

rtt = delta * 4 / interval;
dccp_pr_debug("%s(%p), approximated RTT to %dus\n",
dccp_role(sk), sk, (int)rtt);

/*
* Determine the length of the first loss interval via inverse lookup.
* Assume that X_recv can be computed by the throughput equation
* s
* X_recv = --------
* R * fval
* Find some p such that f(p) = fval; return 1/p [RFC 3448, 6.3.1].
*/
if (rtt == 0) { /* would result in divide-by-zero */
DCCP_WARN("RTT==0\n");
return ~0;
}

delta = ktime_us_delta(ktime_get_real(), last_feedback);
DCCP_BUG_ON(delta <= 0);

x_recv = scaled_div32(bytes_recv, delta);
if (x_recv == 0) { /* would also trigger divide-by-zero */
DCCP_WARN("X_recv==0\n");
if (previous_x_recv == 0) {
DCCP_BUG("stored value of X_recv is zero");
return ~0;
}
x_recv = previous_x_recv;
}

fval = scaled_div(s, rtt);
fval = scaled_div32(fval, x_recv);
p = tfrc_calc_x_reverse_lookup(fval);

dccp_pr_debug("%s(%p), receive rate=%u bytes/s, implied "
"loss rate=%u\n", dccp_role(sk), sk, x_recv, p);

if (p != 0)
return 1000000 / p;
#endif
return ~0;
}

void dccp_li_update_li(struct sock *sk,
struct list_head *li_hist_list,
struct list_head *hist_list,
ktime_t last_feedback, u16 s, u32 bytes_recv,
u32 previous_x_recv, u64 seq_loss, u8 win_loss)
{
struct dccp_li_hist_entry *head;
u64 seq_temp;

if (list_empty(li_hist_list)) {
if (!dccp_li_hist_interval_new(li_hist_list, seq_loss,
win_loss))
return;

head = list_entry(li_hist_list->next, struct dccp_li_hist_entry,
dccplih_node);
head->dccplih_interval = dccp_li_calc_first_li(sk, hist_list,
last_feedback,
s, bytes_recv,
previous_x_recv);
} else {
struct dccp_li_hist_entry *entry;
struct list_head *tail;

head = list_entry(li_hist_list->next, struct dccp_li_hist_entry,
dccplih_node);
/* FIXME win count check removed as was wrong */
/* should make this check with receive history */
/* and compare there as per section 10.2 of RFC4342 */

/* new loss event detected */
/* calculate last interval length */
seq_temp = dccp_delta_seqno(head->dccplih_seqno, seq_loss);
entry = dccp_li_hist_entry_new(GFP_ATOMIC);

if (entry == NULL) {
DCCP_BUG("out of memory - can not allocate entry");
return;
}

list_add(&entry->dccplih_node, li_hist_list);

tail = li_hist_list->prev;
list_del(tail);
kmem_cache_free(dccp_li_cachep, tail);

/* Create the newest interval */
entry->dccplih_seqno = seq_loss;
entry->dccplih_interval = seq_temp;
entry->dccplih_win_count = win_loss;
}
}

EXPORT_SYMBOL_GPL(dccp_li_update_li);

/* Determine if `new_loss' does begin a new loss interval [RFC 4342, 10.2] */
static inline u8 tfrc_lh_is_new_loss(struct tfrc_loss_interval *cur,
struct tfrc_rx_hist_entry *new_loss)
Expand Down
10 changes: 1 addition & 9 deletions net/dccp/ccids/lib/loss_interval.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -65,19 +65,11 @@ static inline u8 tfrc_lh_length(struct tfrc_loss_hist *lh)
return min(lh->counter, (u8)LIH_SIZE);
}

extern void dccp_li_hist_purge(struct list_head *list);
struct tfrc_rx_hist;

extern int tfrc_lh_interval_add(struct tfrc_loss_hist *, struct tfrc_rx_hist *,
u32 (*first_li)(struct sock *), struct sock *);
extern u8 tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *);
extern void tfrc_lh_cleanup(struct tfrc_loss_hist *lh);

extern u32 dccp_li_hist_calc_i_mean(struct list_head *list);

extern void dccp_li_update_li(struct sock *sk,
struct list_head *li_hist_list,
struct list_head *hist_list,
ktime_t last_feedback, u16 s,
u32 bytes_recv, u32 previous_x_recv,
u64 seq_loss, u8 win_loss);
#endif /* _DCCP_LI_HIST_ */

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