The branch stable/14 has been updated by markj:
URL:
https://cgit.FreeBSD.org/src/commit/?id=35e91b0447f185085624ee9c5e529f35bf556184
commit 35e91b0447f185085624ee9c5e529f35bf556184
Author: Mark Johnston <ma...@freebsd.org>
AuthorDate: 2025-05-27 17:08:07 +0000
Commit: Mark Johnston <ma...@freebsd.org>
CommitDate: 2025-06-20 12:46:09 +0000
e1000: Fix some issues in em_newitr()
- Load packet and byte counters exactly once, as they can be
concurrently mutated.
- Rename bytes_packets to bytes_per_packet, which seems clearer.
- Use local variables that have the same types as the counter values,
rather than truncating unsigned long to u32.
Reviewed by: kbowling
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D50416
(cherry picked from commit 731c145612dd6ffe457a562959a5c027acf13334)
---
sys/dev/e1000/if_em.c | 40 ++++++++++++++++++++++------------------
1 file changed, 22 insertions(+), 18 deletions(-)
diff --git a/sys/dev/e1000/if_em.c b/sys/dev/e1000/if_em.c
index 27500f936c25..f0ef6051fab1 100644
--- a/sys/dev/e1000/if_em.c
+++ b/sys/dev/e1000/if_em.c
@@ -1644,14 +1644,16 @@ em_newitr(struct e1000_softc *sc, struct em_rx_queue
*que,
struct tx_ring *txr, struct rx_ring *rxr)
{
struct e1000_hw *hw = &sc->hw;
+ unsigned long bytes, bytes_per_packet, packets;
+ unsigned long rxbytes, rxpackets, txbytes, txpackets;
u32 newitr;
- u32 bytes;
- u32 bytes_packets;
- u32 packets;
u8 nextlatency;
+ rxbytes = atomic_load_long(&rxr->rx_bytes);
+ txbytes = atomic_load_long(&txr->tx_bytes);
+
/* Idle, do nothing */
- if ((txr->tx_bytes == 0) && (rxr->rx_bytes == 0))
+ if (txbytes == 0 && rxbytes == 0)
return;
newitr = 0;
@@ -1671,18 +1673,20 @@ em_newitr(struct e1000_softc *sc, struct em_rx_queue
*que,
goto em_set_next_itr;
}
- bytes = bytes_packets = 0;
+ bytes = bytes_per_packet = 0;
/* Get largest values from the associated tx and rx ring */
- if (txr->tx_bytes && txr->tx_packets) {
- bytes = txr->tx_bytes;
- bytes_packets = txr->tx_bytes/txr->tx_packets;
- packets = txr->tx_packets;
+ txpackets = atomic_load_long(&txr->tx_packets);
+ if (txpackets != 0) {
+ bytes = txbytes;
+ bytes_per_packet = txbytes / txpackets;
+ packets = txpackets;
}
- if (rxr->rx_bytes && rxr->rx_packets) {
- bytes = max(bytes, rxr->rx_bytes);
- bytes_packets =
- max(bytes_packets, rxr->rx_bytes/rxr->rx_packets);
- packets = max(packets, rxr->rx_packets);
+ rxpackets = atomic_load_long(&rxr->rx_packets);
+ if (rxpackets != 0) {
+ bytes = lmax(bytes, rxbytes);
+ bytes_per_packet =
+ lmax(bytes_per_packet, rxbytes / rxpackets);
+ packets = lmax(packets, rxpackets);
}
/* Latency state machine */
@@ -1692,7 +1696,7 @@ em_newitr(struct e1000_softc *sc, struct em_rx_queue *que,
break;
case itr_latency_lowest: /* 70k ints/s */
/* TSO and jumbo frames */
- if (bytes_packets > 8000)
+ if (bytes_per_packet > 8000)
nextlatency = itr_latency_bulk;
else if ((packets < 5) && (bytes > 512))
nextlatency = itr_latency_low;
@@ -1700,14 +1704,14 @@ em_newitr(struct e1000_softc *sc, struct em_rx_queue
*que,
case itr_latency_low: /* 20k ints/s */
if (bytes > 10000) {
/* Handle TSO */
- if (bytes_packets > 8000)
+ if (bytes_per_packet > 8000)
nextlatency = itr_latency_bulk;
else if ((packets < 10) ||
- (bytes_packets > 1200))
+ (bytes_per_packet > 1200))
nextlatency = itr_latency_bulk;
else if (packets > 35)
nextlatency = itr_latency_lowest;
- } else if (bytes_packets > 2000) {
+ } else if (bytes_per_packet > 2000) {
nextlatency = itr_latency_bulk;
} else if (packets < 3 && bytes < 512) {
nextlatency = itr_latency_lowest;
