git: 76578d601e7f - main - bblog: improve timeout event handling

The branch main has been updated by tuexen:

URL: https://cgit.FreeBSD.org/src/commit/?id=76578d601e7fae45edd397b9863b77c3029483ab

commit 76578d601e7fae45edd397b9863b77c3029483ab
Author:     Michael Tuexen <tuexen@FreeBSD.org>
AuthorDate: 2023-02-21 21:38:18 +0000
Commit:     Michael Tuexen <tuexen@FreeBSD.org>
CommitDate: 2023-02-21 21:46:15 +0000

    bblog: improve timeout event handling
    
    Extend the BBLog RTO event to deal with all timers of the base
    stack. Also provide information about starting, stopping, and
    running off. The expiration of the retransmission timer is
    reported as it was done before.
    
    Reviewed by:            rscheff@
    Sponsored by:           Netflix, Inc.
    Differential Revision:  https://reviews.freebsd.org/D38710
---
 sys/netinet/tcp_timer.c | 45 +++++++++++++++++++++++++++++++++++++++++----
 sys/netinet/tcp_var.h   |  7 +++++++
 2 files changed, 48 insertions(+), 4 deletions(-)

diff --git a/sys/netinet/tcp_timer.c b/sys/netinet/tcp_timer.c
index 0186d6a9827a..019f01391f22 100644
--- a/sys/netinet/tcp_timer.c
+++ b/sys/netinet/tcp_timer.c
@@ -542,7 +542,6 @@ tcp_timer_rexmt(struct tcpcb *tp)
 	TCP_PROBE2(debug__user, tp, PRU_SLOWTIMO);
 	CURVNET_SET(inp->inp_vnet);
 	tcp_free_sackholes(tp);
-	TCP_LOG_EVENT(tp, NULL, NULL, NULL, TCP_LOG_RTO, 0, 0, NULL, false);
 	if (tp->t_fb->tfb_tcp_rexmit_tmr) {
 		/* The stack has a timer action too. */
 		(*tp->t_fb->tfb_tcp_rexmit_tmr)(tp);
@@ -790,6 +789,35 @@ tcp_timer_rexmt(struct tcpcb *tp)
 	return (rv);
 }
 
+static void
+tcp_bblog_timer(struct tcpcb *tp, tt_which which, tt_what what, uint32_t ticks)
+{
+	struct tcp_log_buffer *lgb;
+	uint64_t ms;
+
+	INP_WLOCK_ASSERT(tptoinpcb(tp));
+	if (tp->t_logstate != TCP_LOG_STATE_OFF)
+		lgb = tcp_log_event_(tp, NULL, NULL, NULL, TCP_LOG_RTO, 0, 0,
+		    NULL, false, NULL, NULL, 0, NULL);
+	else
+		lgb = NULL;
+	if (lgb != NULL) {
+		lgb->tlb_flex1 = (what << 8) | which;
+		if (what == TT_STARTING) {
+			/* Convert ticks to ms and store it in tlb_flex2. */
+			if (hz == 1000)
+				lgb->tlb_flex2 = ticks;
+			else {
+				ms = (((uint64_t)ticks * 1000) + (hz - 1)) / hz;
+				if (ms > UINT32_MAX)
+					lgb->tlb_flex2 = UINT32_MAX;
+				else
+					lgb->tlb_flex2 = (uint32_t)ms;
+			}
+		}
+	}
+}
+
 static inline tt_which
 tcp_timer_next(struct tcpcb *tp, sbintime_t *precision)
 {
@@ -816,6 +844,7 @@ tcp_timer_enter(void *xtp)
 	struct inpcb *inp = tptoinpcb(tp);
 	sbintime_t precision;
 	tt_which which;
+	bool tp_valid;
 
 	INP_WLOCK_ASSERT(inp);
 	MPASS((curthread->td_pflags & TDP_INTCPCALLOUT) == 0);
@@ -827,7 +856,10 @@ tcp_timer_enter(void *xtp)
 	tp->t_timers[which] = SBT_MAX;
 	tp->t_precisions[which] = 0;
 
-	if (tcp_timersw[which](tp)) {
+	tcp_bblog_timer(tp, which, TT_PROCESSING, 0);
+	tp_valid = tcp_timersw[which](tp);
+	if (tp_valid) {
+		tcp_bblog_timer(tp, which, TT_PROCESSED, 0);
 		if ((which = tcp_timer_next(tp, &precision)) != TT_N) {
 			callout_reset_sbt_on(&tp->t_callout,
 			    tp->t_timers[which], precision, tcp_timer_enter,
@@ -847,6 +879,7 @@ tcp_timer_activate(struct tcpcb *tp, tt_which which, u_int delta)
 {
 	struct inpcb *inp = tptoinpcb(tp);
 	sbintime_t precision;
+	tt_what what;
 
 #ifdef TCP_OFFLOAD
 	if (tp->t_flags & TF_TOE)
@@ -855,11 +888,15 @@ tcp_timer_activate(struct tcpcb *tp, tt_which which, u_int delta)
 
 	INP_WLOCK_ASSERT(inp);
 
-	if (delta > 0)
+	if (delta > 0) {
+		what = TT_STARTING;
 		callout_when(tick_sbt * delta, 0, C_HARDCLOCK,
 		    &tp->t_timers[which], &tp->t_precisions[which]);
-	else
+	} else {
+		what = TT_STOPPING;
 		tp->t_timers[which] = SBT_MAX;
+	}
+	tcp_bblog_timer(tp, which, what, delta);
 
 	if ((which = tcp_timer_next(tp, &precision)) != TT_N)
 		callout_reset_sbt_on(&tp->t_callout, tp->t_timers[which],
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index cd457893e36f..1be3244e15c5 100644
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -135,6 +135,13 @@ typedef enum {
 	TT_N,
 } tt_which;
 
+typedef enum {
+	TT_PROCESSING = 0,
+	TT_PROCESSED,
+	TT_STARTING,
+	TT_STOPPING,
+} tt_what;
+
 /*
  * Tcp control block, one per tcp connection.
  */