Commit f3fafbcb authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'L4S-style-ce_threshold_ect1-marking' 



Eric Dumazet says:

====================
net/sched: implement L4S style ce_threshold_ect1 marking

As suggested by Ingemar Johansson, Neal Cardwell, and others, fq_codel can be used
for Low Latency, Low Loss, Scalable Throughput (L4S) with a small change.

In ce_threshold_ect1 mode, only ECT(1) packets can be marked to CE if
their sojourn time is above the threshold.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 19757ceb e72aeb9e

include/net/codel.h

+2 −0
Original line number Diff line number Diff line
@@ -102,6 +102,7 @@ static inline u32 codel_time_to_us(codel_time_t val) 
 * @interval:	width of moving time window

 * @mtu:	device mtu, or minimal queue backlog in bytes.

 * @ecn:	is Explicit Congestion Notification enabled

 * @ce_threshold_ect1: if ce_threshold only marks ECT(1) packets

 */

struct codel_params {

	codel_time_t	target;
@@ -109,6 +110,7 @@ struct codel_params { 
	codel_time_t	interval;

	u32		mtu;

	bool		ecn;

	bool		ce_threshold_ect1;

};



/**

include/net/codel_impl.h

+15 −3
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ static void codel_params_init(struct codel_params *params) 
	params->interval = MS2TIME(100);

	params->target = MS2TIME(5);

	params->ce_threshold = CODEL_DISABLED_THRESHOLD;

	params->ce_threshold_ect1 = false;

	params->ecn = false;

}
@@ -246,9 +247,20 @@ static struct sk_buff *codel_dequeue(void *ctx, 
						    vars->rec_inv_sqrt);

	}

end:

	if (skb && codel_time_after(vars->ldelay, params->ce_threshold) &&

	    INET_ECN_set_ce(skb))

	if (skb && codel_time_after(vars->ldelay, params->ce_threshold)) {

		bool set_ce = true;



		if (params->ce_threshold_ect1) {

			/* Note: if skb_get_dsfield() returns -1, following

			 * gives INET_ECN_MASK, which is != INET_ECN_ECT_1.

			 */

			u8 ecn = skb_get_dsfield(skb) & INET_ECN_MASK;



			set_ce = (ecn == INET_ECN_ECT_1);

		}

		if (set_ce && INET_ECN_set_ce(skb))

			stats->ce_mark++;

	}

	return skb;

}

include/net/inet_ecn.h

+17 −0
Original line number Diff line number Diff line
@@ -188,6 +188,23 @@ static inline int INET_ECN_set_ce(struct sk_buff *skb) 
	return 0;

}



static inline int skb_get_dsfield(struct sk_buff *skb)

{

	switch (skb_protocol(skb, true)) {

	case cpu_to_be16(ETH_P_IP):

		if (!pskb_network_may_pull(skb, sizeof(struct iphdr)))

			break;

		return ipv4_get_dsfield(ip_hdr(skb));



	case cpu_to_be16(ETH_P_IPV6):

		if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))

			break;

		return ipv6_get_dsfield(ipv6_hdr(skb));

	}



	return -1;

}



static inline int INET_ECN_set_ect1(struct sk_buff *skb)

{

	switch (skb_protocol(skb, true)) {

include/uapi/linux/pkt_sched.h

+1 −0
Original line number Diff line number Diff line
@@ -840,6 +840,7 @@ enum { 
	TCA_FQ_CODEL_CE_THRESHOLD,

	TCA_FQ_CODEL_DROP_BATCH_SIZE,

	TCA_FQ_CODEL_MEMORY_LIMIT,

	TCA_FQ_CODEL_CE_THRESHOLD_ECT1,

	__TCA_FQ_CODEL_MAX

};

net/mac80211/sta_info.c

+1 −0
Original line number Diff line number Diff line
@@ -513,6 +513,7 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata, 
	sta->cparams.target = MS2TIME(20);

	sta->cparams.interval = MS2TIME(100);

	sta->cparams.ecn = true;

	sta->cparams.ce_threshold_ect1 = false;



	sta_dbg(sdata, "Allocated STA %pM\n", sta->sta.addr);