tcp/lro: Allow drivers to set the TCP ACK/data segment aggregation limit

ACK aggregation limit is append count based, while the TCP data segment
aggregation limit is length based.  Unless the network driver sets these
two limits, it's an NO-OP.

Reviewed by:	adrian, gallatin (previous version), hselasky (previous version)
Approved by:	adrian (mentor)
MFC after:	1 week
Sponsored by:	Microsoft OSTC
Differential Revision:	https://reviews.freebsd.org/D5185
This commit is contained in:
Sepherosa Ziehau 2016-02-18 04:58:34 +00:00
parent 4a1ff07b39
commit 7ae3d4bf54
3 changed files with 19 additions and 3 deletions

View File

@ -88,6 +88,8 @@ tcp_lro_init_args(struct lro_ctrl *lc, struct ifnet *ifp,
lc->lro_mbuf_count = 0;
lc->lro_mbuf_max = lro_mbufs;
lc->lro_cnt = lro_entries;
lc->lro_ackcnt_lim = TCP_LRO_ACKCNT_MAX;
lc->lro_length_lim = TCP_LRO_LENGTH_MAX;
lc->ifp = ifp;
SLIST_INIT(&lc->lro_free);
SLIST_INIT(&lc->lro_active);
@ -610,7 +612,7 @@ tcp_lro_rx(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum)
}
/* Flush now if appending will result in overflow. */
if (le->p_len > (65535 - tcp_data_len)) {
if (le->p_len > (lc->lro_length_lim - tcp_data_len)) {
SLIST_REMOVE(&lc->lro_active, le, lro_entry, next);
tcp_lro_flush(lc, le);
break;
@ -648,6 +650,15 @@ tcp_lro_rx(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum)
if (tcp_data_len == 0) {
m_freem(m);
/*
* Flush this LRO entry, if this ACK should not
* be further delayed.
*/
if (le->append_cnt >= lc->lro_ackcnt_lim) {
SLIST_REMOVE(&lc->lro_active, le, lro_entry,
next);
tcp_lro_flush(lc, le);
}
return (0);
}
@ -668,7 +679,7 @@ tcp_lro_rx(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum)
* If a possible next full length packet would cause an
* overflow, pro-actively flush now.
*/
if (le->p_len > (65535 - lc->ifp->if_mtu)) {
if (le->p_len > (lc->lro_length_lim - lc->ifp->if_mtu)) {
SLIST_REMOVE(&lc->lro_active, le, lro_entry, next);
tcp_lro_flush(lc, le);
} else

View File

@ -91,11 +91,16 @@ struct lro_ctrl {
unsigned lro_cnt;
unsigned lro_mbuf_count;
unsigned lro_mbuf_max;
unsigned short lro_ackcnt_lim; /* max # of aggregated ACKs */
unsigned lro_length_lim; /* max len of aggregated data */
struct lro_head lro_active;
struct lro_head lro_free;
};
#define TCP_LRO_LENGTH_MAX 65535
#define TCP_LRO_ACKCNT_MAX 65535 /* unlimited */
int tcp_lro_init(struct lro_ctrl *);
int tcp_lro_init_args(struct lro_ctrl *, struct ifnet *, unsigned, unsigned);
void tcp_lro_free(struct lro_ctrl *);

View File

@ -58,7 +58,7 @@
* in the range 5 to 9.
*/
#undef __FreeBSD_version
#define __FreeBSD_version 1100098 /* Master, propagated to newvers */
#define __FreeBSD_version 1100099 /* Master, propagated to newvers */
/*
* __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD,