From: "Morten Brørup" <mb@smartsharesystems.com>
To: dev@dpdk.org, Stephen Hemminger <stephen@networkplumber.org>
Cc: techboard@dpdk.org, "Morten Brørup" <mb@smartsharesystems.com>
Subject: [PATCH] Revert "net/null: add fast mbuf release Tx offload"
Date: Wed, 5 Nov 2025 08:19:52 +0000 [thread overview]
Message-ID: <20251105081953.20153-1-mb@smartsharesystems.com> (raw)
This reverts commit 675ddc233d68d90b3858cdb6267dd407c4e85984.
The Tech Board has decided that the co-existence of fast mbuf release and
multi segments is unclear, and new restrictions should not be imposed
until this has been clarified.
Fixes: 675ddc233d68 ("net/null: add fast mbuf release Tx offload")
Signed-off-by: Morten Brørup <mb@smartsharesystems.com>
---
drivers/net/null/rte_eth_null.c | 143 +++++++-------------------------
1 file changed, 28 insertions(+), 115 deletions(-)
diff --git a/drivers/net/null/rte_eth_null.c b/drivers/net/null/rte_eth_null.c
index 14bc65c8ad..46e7e7bd8c 100644
--- a/drivers/net/null/rte_eth_null.c
+++ b/drivers/net/null/rte_eth_null.c
@@ -34,17 +34,6 @@ struct pmd_internals;
struct null_queue {
struct pmd_internals *internals;
- /**
- * For RX queue:
- * Mempool to allocate mbufs from.
- *
- * For TX queue:
- * Mempool to free mbufs to, if fast release of mbufs is enabled.
- * UINTPTR_MAX if the mempool for fast release of mbufs has not yet been detected.
- * NULL if fast release of mbufs is not enabled.
- *
- * @see RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE
- */
struct rte_mempool *mb_pool;
void *dummy_packet;
@@ -152,15 +141,8 @@ eth_null_no_rx(void *q __rte_unused, struct rte_mbuf **bufs __rte_unused,
return 0;
}
-enum eth_tx_free_mode {
- ETH_TX_FREE_MODE_NO_MBUF_FAST_FREE, /* MBUF_FAST_FREE not possible. */
- ETH_TX_FREE_MODE_MBUF_FAST_FREE, /* MBUF_FAST_FREE enabled for the device. */
- ETH_TX_FREE_MODE_PER_QUEUE, /* Varies per TX queue. */
-};
-
-static __rte_always_inline uint16_t
-eth_null_tx_common(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs,
- enum eth_tx_free_mode mode)
+static uint16_t
+eth_null_tx(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
{
struct null_queue *h = q;
unsigned int i;
@@ -169,42 +151,13 @@ eth_null_tx_common(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs,
for (i = 0; i < nb_bufs; i++)
bytes += rte_pktmbuf_pkt_len(bufs[i]);
- if (mode == ETH_TX_FREE_MODE_MBUF_FAST_FREE ||
- (mode == ETH_TX_FREE_MODE_PER_QUEUE && h->mb_pool != NULL)) {
- /* RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE */
- if (unlikely(h->mb_pool == (void *)UINTPTR_MAX)) {
- if (unlikely(nb_bufs == 0))
- return 0; /* Do not dereference uninitialized bufs[0]. */
- h->mb_pool = bufs[0]->pool;
- }
- rte_mbuf_raw_free_bulk(h->mb_pool, bufs, nb_bufs);
- } else {
- rte_pktmbuf_free_bulk(bufs, nb_bufs);
- }
+ rte_pktmbuf_free_bulk(bufs, nb_bufs);
rte_atomic_fetch_add_explicit(&h->tx_pkts, nb_bufs, rte_memory_order_relaxed);
rte_atomic_fetch_add_explicit(&h->tx_bytes, bytes, rte_memory_order_relaxed);
return nb_bufs;
}
-static uint16_t
-eth_null_tx(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
-{
- return eth_null_tx_common(q, bufs, nb_bufs, ETH_TX_FREE_MODE_PER_QUEUE);
-}
-
-static uint16_t
-eth_null_tx_no_mbuf_fast_free(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
-{
- return eth_null_tx_common(q, bufs, nb_bufs, ETH_TX_FREE_MODE_NO_MBUF_FAST_FREE);
-}
-
-static uint16_t
-eth_null_tx_mbuf_fast_free(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
-{
- return eth_null_tx_common(q, bufs, nb_bufs, ETH_TX_FREE_MODE_MBUF_FAST_FREE);
-}
-
static uint16_t
eth_null_copy_tx(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
{
@@ -225,48 +178,9 @@ eth_null_copy_tx(void *q, struct rte_mbuf **bufs, uint16_t nb_bufs)
return nb_bufs;
}
-static void
-eth_dev_assign_rxtx_ops(struct rte_eth_dev *dev)
-{
- struct pmd_internals *internals = dev->data->dev_private;
-
- if (internals->packet_copy) {
- dev->rx_pkt_burst = eth_null_copy_rx;
- dev->tx_pkt_burst = eth_null_copy_tx;
- } else {
- if (internals->no_rx)
- dev->rx_pkt_burst = eth_null_no_rx;
- else
- dev->rx_pkt_burst = eth_null_rx;
-
- dev->tx_pkt_burst = eth_null_tx;
- if (dev->data->dev_conf.txmode.offloads & RTE_ETH_TX_OFFLOAD_MULTI_SEGS)
- dev->tx_pkt_burst = eth_null_tx_no_mbuf_fast_free;
- if (dev->data->dev_conf.txmode.offloads & RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE)
- dev->tx_pkt_burst = eth_null_tx_mbuf_fast_free;
- }
-}
-
static int
-eth_dev_configure(struct rte_eth_dev *dev)
+eth_dev_configure(struct rte_eth_dev *dev __rte_unused)
{
- struct pmd_internals *internals = dev->data->dev_private;
-
- if ((dev->data->dev_conf.txmode.offloads &
- (RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE | RTE_ETH_TX_OFFLOAD_MULTI_SEGS)) ==
- (RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE | RTE_ETH_TX_OFFLOAD_MULTI_SEGS)) {
- PMD_LOG(ERR,
- "TX offloads MBUF_FAST_FREE and MULTI_SEGS are mutually exclusive");
- return -EINVAL;
- }
- if (dev->data->dev_conf.txmode.offloads & RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE &&
- internals->packet_copy) {
- PMD_LOG(INFO,
- "TX offload MBUF_FAST_FREE is ignored with %s argument",
- ETH_NULL_PACKET_COPY_ARG);
- }
- /* Assign RX/TX ops depending on device TX offloads. */
- eth_dev_assign_rxtx_ops(dev);
return 0;
}
@@ -345,7 +259,7 @@ static int
eth_tx_queue_setup(struct rte_eth_dev *dev, uint16_t tx_queue_id,
uint16_t nb_tx_desc __rte_unused,
unsigned int socket_id __rte_unused,
- const struct rte_eth_txconf *tx_conf)
+ const struct rte_eth_txconf *tx_conf __rte_unused)
{
struct rte_mbuf *dummy_packet;
struct pmd_internals *internals;
@@ -359,20 +273,6 @@ eth_tx_queue_setup(struct rte_eth_dev *dev, uint16_t tx_queue_id,
if (tx_queue_id >= dev->data->nb_tx_queues)
return -ENODEV;
- if (((dev->data->dev_conf.txmode.offloads | tx_conf->offloads) &
- (RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE | RTE_ETH_TX_OFFLOAD_MULTI_SEGS)) ==
- (RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE | RTE_ETH_TX_OFFLOAD_MULTI_SEGS)) {
- PMD_LOG(ERR,
- "TX offloads MBUF_FAST_FREE and MULTI_SEGS are mutually exclusive");
- return -EINVAL;
- }
- if (tx_conf->offloads & RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE &&
- internals->packet_copy) {
- PMD_LOG(INFO,
- "TX offload MBUF_FAST_FREE is ignored with %s argument",
- ETH_NULL_PACKET_COPY_ARG);
- }
-
packet_size = internals->packet_size;
dev->data->tx_queues[tx_queue_id] =
@@ -384,10 +284,6 @@ eth_tx_queue_setup(struct rte_eth_dev *dev, uint16_t tx_queue_id,
internals->tx_null_queues[tx_queue_id].internals = internals;
internals->tx_null_queues[tx_queue_id].dummy_packet = dummy_packet;
- internals->tx_null_queues[tx_queue_id].mb_pool =
- (dev->data->dev_conf.txmode.offloads | tx_conf->offloads) &
- RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE ?
- (void *)UINTPTR_MAX : NULL;
return 0;
}
@@ -413,10 +309,7 @@ eth_dev_info(struct rte_eth_dev *dev,
dev_info->max_rx_queues = RTE_DIM(internals->rx_null_queues);
dev_info->max_tx_queues = RTE_DIM(internals->tx_null_queues);
dev_info->min_rx_bufsize = 0;
- dev_info->tx_queue_offload_capa = RTE_ETH_TX_OFFLOAD_MULTI_SEGS |
- RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE;
- dev_info->tx_offload_capa = RTE_ETH_TX_OFFLOAD_MT_LOCKFREE |
- dev_info->tx_queue_offload_capa;
+ dev_info->tx_offload_capa = RTE_ETH_TX_OFFLOAD_MULTI_SEGS | RTE_ETH_TX_OFFLOAD_MT_LOCKFREE;
dev_info->reta_size = internals->reta_size;
dev_info->flow_type_rss_offloads = internals->flow_type_rss_offloads;
@@ -698,7 +591,16 @@ eth_dev_null_create(struct rte_vdev_device *dev, struct pmd_options *args)
eth_dev->dev_ops = &ops;
/* finally assign rx and tx ops */
- eth_dev_assign_rxtx_ops(eth_dev);
+ if (internals->packet_copy) {
+ eth_dev->rx_pkt_burst = eth_null_copy_rx;
+ eth_dev->tx_pkt_burst = eth_null_copy_tx;
+ } else if (internals->no_rx) {
+ eth_dev->rx_pkt_burst = eth_null_no_rx;
+ eth_dev->tx_pkt_burst = eth_null_tx;
+ } else {
+ eth_dev->rx_pkt_burst = eth_null_rx;
+ eth_dev->tx_pkt_burst = eth_null_tx;
+ }
rte_eth_dev_probing_finish(eth_dev);
return 0;
@@ -777,6 +679,7 @@ rte_pmd_null_probe(struct rte_vdev_device *dev)
PMD_LOG(INFO, "Initializing pmd_null for %s", name);
if (rte_eal_process_type() == RTE_PROC_SECONDARY) {
+ struct pmd_internals *internals;
eth_dev = rte_eth_dev_attach_secondary(name);
if (!eth_dev) {
PMD_LOG(ERR, "Failed to probe %s", name);
@@ -785,7 +688,17 @@ rte_pmd_null_probe(struct rte_vdev_device *dev)
/* TODO: request info from primary to set up Rx and Tx */
eth_dev->dev_ops = &ops;
eth_dev->device = &dev->device;
- eth_dev_assign_rxtx_ops(eth_dev);
+ internals = eth_dev->data->dev_private;
+ if (internals->packet_copy) {
+ eth_dev->rx_pkt_burst = eth_null_copy_rx;
+ eth_dev->tx_pkt_burst = eth_null_copy_tx;
+ } else if (internals->no_rx) {
+ eth_dev->rx_pkt_burst = eth_null_no_rx;
+ eth_dev->tx_pkt_burst = eth_null_tx;
+ } else {
+ eth_dev->rx_pkt_burst = eth_null_rx;
+ eth_dev->tx_pkt_burst = eth_null_tx;
+ }
rte_eth_dev_probing_finish(eth_dev);
return 0;
}
--
2.43.0
reply other threads:[~2025-11-05 8:20 UTC|newest]
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