git: 618d49f5cad1 - main - Revert "iflib: Relax timer period from 0.5 to 0.5-0.75s."

The branch main has been updated by mav:

URL: https://cgit.FreeBSD.org/src/commit/?id=618d49f5cad1dfd59eab6561ecf93d053610609d

commit 618d49f5cad1dfd59eab6561ecf93d053610609d
Author:     Alexander Motin <mav@FreeBSD.org>
AuthorDate: 2022-01-10 14:35:01 +0000
Commit:     Alexander Motin <mav@FreeBSD.org>
CommitDate: 2022-01-10 14:40:38 +0000

    Revert "iflib: Relax timer period from 0.5 to 0.5-0.75s."
    
    I've noticed relations between iflib_timer() vs ixl_admin_timer().
    Both scheduled at the same 2Hz rate, but the second is rescheduling
    the first each time, so if the first get any slower, it won't be
    executed at all.  Revert this until deeper investigation.
    
    This reverts commit 90bc1cf65778aafb1f226c8fe08218cfed5e40b2.
---
 sys/net/iflib.c | 56 +++++++++++++++++++++++++++++---------------------------
 1 file changed, 29 insertions(+), 27 deletions(-)

diff --git a/sys/net/iflib.c b/sys/net/iflib.c
index 180b42731e1f..3fcab699f9e0 100644
--- a/sys/net/iflib.c
+++ b/sys/net/iflib.c
@@ -337,6 +337,7 @@ struct iflib_txq {
 	uint64_t	ift_map_failed;
 	uint64_t	ift_txd_encap_efbig;
 	uint64_t	ift_pullups;
+	uint64_t	ift_last_timer_tick;
 
 	struct mtx	ift_mtx;
 	struct mtx	ift_db_mtx;
@@ -586,9 +587,9 @@ SYSCTL_INT(_net_iflib, OID_AUTO, min_tx_latency, CTLFLAG_RW,
 static int iflib_no_tx_batch = 0;
 SYSCTL_INT(_net_iflib, OID_AUTO, no_tx_batch, CTLFLAG_RW,
 		   &iflib_no_tx_batch, 0, "minimize transmit latency at the possible expense of throughput");
-static int iflib_timer_period = 500;
-SYSCTL_INT(_net_iflib, OID_AUTO, timer_period, CTLFLAG_RW,
-		   &iflib_timer_period, 0, "milliseconds between iflib_timer calls");
+static int iflib_timer_default = 1000;
+SYSCTL_INT(_net_iflib, OID_AUTO, timer_default, CTLFLAG_RW,
+		   &iflib_timer_default, 0, "number of ticks between iflib_timer calls");
 
 
 #if IFLIB_DEBUG_COUNTERS
@@ -2392,6 +2393,7 @@ iflib_timer(void *arg)
 	iflib_txq_t txq = arg;
 	if_ctx_t ctx = txq->ift_ctx;
 	if_softc_ctx_t sctx = &ctx->ifc_softc_ctx;
+	uint64_t this_tick = ticks;
 
 	if (!(if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING))
 		return;
@@ -2401,28 +2403,30 @@ iflib_timer(void *arg)
 	** can be done without the lock because its RO
 	** and the HUNG state will be static if set.
 	*/
-	IFDI_TIMER(ctx, txq->ift_id);
-	if ((txq->ift_qstatus == IFLIB_QUEUE_HUNG) &&
-	    ((txq->ift_cleaned_prev == txq->ift_cleaned) ||
-	     (sctx->isc_pause_frames == 0)))
-		goto hung;
-	if (txq->ift_qstatus != IFLIB_QUEUE_IDLE &&
-	    ifmp_ring_is_stalled(txq->ift_br)) {
-		KASSERT(ctx->ifc_link_state == LINK_STATE_UP,
-		    ("queue can't be marked as hung if interface is down"));
-		txq->ift_qstatus = IFLIB_QUEUE_HUNG;
-	}
-	txq->ift_cleaned_prev = txq->ift_cleaned;
-
+	if (this_tick - txq->ift_last_timer_tick >= iflib_timer_default) {
+		txq->ift_last_timer_tick = this_tick;
+		IFDI_TIMER(ctx, txq->ift_id);
+		if ((txq->ift_qstatus == IFLIB_QUEUE_HUNG) &&
+		    ((txq->ift_cleaned_prev == txq->ift_cleaned) ||
+		     (sctx->isc_pause_frames == 0)))
+			goto hung;
+
+		if (txq->ift_qstatus != IFLIB_QUEUE_IDLE &&
+		    ifmp_ring_is_stalled(txq->ift_br)) {
+			KASSERT(ctx->ifc_link_state == LINK_STATE_UP,
+			    ("queue can't be marked as hung if interface is down"));
+			txq->ift_qstatus = IFLIB_QUEUE_HUNG;
+		}
+		txq->ift_cleaned_prev = txq->ift_cleaned;
+	}
 	/* handle any laggards */
 	if (txq->ift_db_pending)
 		GROUPTASK_ENQUEUE(&txq->ift_task);
 
 	sctx->isc_pause_frames = 0;
-	if (if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING)
-		callout_reset_sbt_on(&txq->ift_timer,
-		    iflib_timer_period * SBT_1MS, 0,
-		    iflib_timer, txq, txq->ift_timer.c_cpu, C_PREL(1));
+	if (if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING) 
+		callout_reset_on(&txq->ift_timer, iflib_timer_default, iflib_timer,
+		    txq, txq->ift_timer.c_cpu);
 	return;
 
  hung:
@@ -2540,9 +2544,8 @@ done:
 	IFDI_INTR_ENABLE(ctx);
 	txq = ctx->ifc_txqs;
 	for (i = 0; i < sctx->isc_ntxqsets; i++, txq++)
-		callout_reset_sbt_on(&txq->ift_timer,
-		    iflib_timer_period * SBT_1MS, 0,
-		    iflib_timer, txq, txq->ift_timer.c_cpu, C_PREL(1));
+		callout_reset_on(&txq->ift_timer, iflib_timer_default, iflib_timer, txq,
+			txq->ift_timer.c_cpu);
 
         /* Re-enable txsync/rxsync. */
 	netmap_enable_all_rings(ifp);
@@ -4064,9 +4067,8 @@ _task_fn_admin(void *context)
 	}
 	IFDI_UPDATE_ADMIN_STATUS(ctx);
 	for (txq = ctx->ifc_txqs, i = 0; i < sctx->isc_ntxqsets; i++, txq++) {
-		callout_reset_sbt_on(&txq->ift_timer,
-		    iflib_timer_period * SBT_1MS, 0,
-		    iflib_timer, txq, txq->ift_timer.c_cpu, C_PREL(1));
+		callout_reset_on(&txq->ift_timer, iflib_timer_default, iflib_timer, txq,
+		    txq->ift_timer.c_cpu);
 	}
 	IFDI_LINK_INTR_ENABLE(ctx);
 	if (do_reset)
@@ -5719,7 +5721,7 @@ iflib_device_iov_add_vf(device_t dev, uint16_t vfnum, const nvlist_t *params)
 static int
 iflib_module_init(void)
 {
-
+	iflib_timer_default = hz / 2;
 	return (0);
 }