[TFRC]: Remove previous loss intervals implementation (3f71c81a) · Commits · e / devices / android_kernel_xiaomi_markw

net/dccp/ccids/lib/loss_interval.c

+0 −266

Original line number	Diff line number	Diff line
		@@ -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 };
		@@ -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;
		@@ -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)

net/dccp/ccids/lib/loss_interval.h

+1 −9

Original line number	Diff line number	Diff line
		@@ -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_ */