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5295 remove maxburst logic from TCP's send algorithm Reviewed by: Dan McDonald <danmcd@omniti.com>
*** 19,28 ****
--- 19,29 ----
* CDDL HEADER END
*/
/*
* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014 by Delphix. All rights reserved.
*/
/* This file contains all TCP output processing functions. */
#include <sys/types.h>
*** 1759,1777 ****
/*
* tcp_send() is called by tcp_wput_data() and returns one of the following:
*
* -1 = failed allocation.
! * 0 = success; burst count reached, or usable send window is too small,
! * and that we'd rather wait until later before sending again.
*/
static int
tcp_send(tcp_t *tcp, const int mss, const int total_hdr_len,
const int tcp_hdr_len, const int num_sack_blk, int *usable,
uint_t *snxt, int *tail_unsent, mblk_t **xmit_tail, mblk_t *local_time)
{
- int num_burst_seg = tcp->tcp_snd_burst;
int num_lso_seg = 1;
uint_t lso_usable;
boolean_t do_lso_send = B_FALSE;
tcp_stack_t *tcps = tcp->tcp_tcps;
conn_t *connp = tcp->tcp_connp;
--- 1760,1777 ----
/*
* tcp_send() is called by tcp_wput_data() and returns one of the following:
*
* -1 = failed allocation.
! * 0 = We've either successfully sent data, or our usable send window is too
! * small and we'd rather wait until later before sending again.
*/
static int
tcp_send(tcp_t *tcp, const int mss, const int total_hdr_len,
const int tcp_hdr_len, const int num_sack_blk, int *usable,
uint_t *snxt, int *tail_unsent, mblk_t **xmit_tail, mblk_t *local_time)
{
int num_lso_seg = 1;
uint_t lso_usable;
boolean_t do_lso_send = B_FALSE;
tcp_stack_t *tcps = tcp->tcp_tcps;
conn_t *connp = tcp->tcp_connp;
*** 1793,1821 ****
mblk_t *mp, *mp1;
uchar_t *rptr;
int len;
/*
- * Burst count reached, return successfully.
- */
- if (num_burst_seg == 0)
- break;
-
- /*
* Calculate the maximum payload length we can send at one
* time.
*/
if (do_lso_send) {
/*
! * Check whether be able to to do LSO for the current
! * available data.
*/
! if (num_burst_seg >= 2 && (*usable - 1) / mss >= 1) {
lso_usable = MIN(tcp->tcp_lso_max, *usable);
- lso_usable = MIN(lso_usable,
- num_burst_seg * mss);
-
num_lso_seg = lso_usable / mss;
if (lso_usable % mss) {
num_lso_seg++;
tcp->tcp_last_sent_len = (ushort_t)
(lso_usable % mss);
--- 1793,1812 ----
mblk_t *mp, *mp1;
uchar_t *rptr;
int len;
/*
* Calculate the maximum payload length we can send at one
* time.
*/
if (do_lso_send) {
/*
! * Determine whether or not it's possible to do LSO,
! * and if so, how much data we can send.
*/
! if ((*usable - 1) / mss >= 1) {
lso_usable = MIN(tcp->tcp_lso_max, *usable);
num_lso_seg = lso_usable / mss;
if (lso_usable % mss) {
num_lso_seg++;
tcp->tcp_last_sent_len = (ushort_t)
(lso_usable % mss);
*** 1828,1845 ****
lso_usable = mss;
}
}
ASSERT(num_lso_seg <= IP_MAXPACKET / mss + 1);
- #ifdef DEBUG
- DTRACE_PROBE2(tcp_send_lso, int, num_lso_seg, boolean_t,
- do_lso_send);
- #endif
- /*
- * Adjust num_burst_seg here.
- */
- num_burst_seg -= num_lso_seg;
len = mss;
if (len > *usable) {
ASSERT(do_lso_send == B_FALSE);
--- 1819,1828 ----
*** 3422,3444 ****
}
/*
* tcp_ss_rexmit() is called to do slow start retransmission after a timeout
* or ICMP errors.
- *
- * To limit the number of duplicate segments, we limit the number of segment
- * to be sent in one time to tcp_snd_burst, the burst variable.
*/
void
tcp_ss_rexmit(tcp_t *tcp)
{
uint32_t snxt;
uint32_t smax;
int32_t win;
int32_t mss;
int32_t off;
- int32_t burst = tcp->tcp_snd_burst;
mblk_t *snxt_mp;
tcp_stack_t *tcps = tcp->tcp_tcps;
/*
* Note that tcp_rexmit can be set even though TCP has retransmitted
--- 3405,3423 ----
*** 3453,3464 ****
win = MIN(tcp->tcp_cwnd, tcp->tcp_swnd);
win -= snxt - tcp->tcp_suna;
mss = tcp->tcp_mss;
snxt_mp = tcp_get_seg_mp(tcp, snxt, &off);
! while (SEQ_LT(snxt, smax) && (win > 0) &&
! (burst > 0) && (snxt_mp != NULL)) {
mblk_t *xmit_mp;
mblk_t *old_snxt_mp = snxt_mp;
uint32_t cnt = mss;
if (win < cnt) {
--- 3432,3442 ----
win = MIN(tcp->tcp_cwnd, tcp->tcp_swnd);
win -= snxt - tcp->tcp_suna;
mss = tcp->tcp_mss;
snxt_mp = tcp_get_seg_mp(tcp, snxt, &off);
! while (SEQ_LT(snxt, smax) && (win > 0) && (snxt_mp != NULL)) {
mblk_t *xmit_mp;
mblk_t *old_snxt_mp = snxt_mp;
uint32_t cnt = mss;
if (win < cnt) {
*** 3483,3493 ****
old_snxt_mp->b_prev = (mblk_t *)ddi_get_lbolt();
TCPS_BUMP_MIB(tcps, tcpRetransSegs);
TCPS_UPDATE_MIB(tcps, tcpRetransBytes, cnt);
tcp->tcp_rexmit_nxt = snxt;
- burst--;
}
/*
* If we have transmitted all we have at the time
* we started the retranmission, we can leave
* the rest of the job to tcp_wput_data(). But we
--- 3461,3470 ----
*** 3524,3534 ****
tcp->tcp_rexmit_max = tcp->tcp_snxt;
tcp->tcp_rexmit_nxt = tcp->tcp_suna;
tcp->tcp_rexmit = B_TRUE;
tcp->tcp_dupack_cnt = 0;
- tcp->tcp_snd_burst = TCP_CWND_SS;
tcp_ss_rexmit(tcp);
}
/*
* tcp_get_seg_mp() is called to get the pointer to a segment in the
--- 3501,3510 ----