#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 };
}
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;
}
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)
projects / linux-2.6 / commitdiff