diff options
| author | Jakub Kicinski <kuba@kernel.org> | 2026-06-01 17:37:59 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-06-03 19:18:06 -0700 |
| commit | bd3beb5c8691318048043d6d2c78d78189d66bdd (patch) | |
| tree | ed82cef472715113f23a090510419aeac766774c | |
| parent | ee5aee77bcba421fd2830e5036a18c206f7c2844 (diff) | |
| download | linux-bd3beb5c8691318048043d6d2c78d78189d66bdd.tar.gz linux-bd3beb5c8691318048043d6d2c78d78189d66bdd.zip | |
eth: bnxt: disable rx-copybreak by default
rx-copybreak requires an extra slab allocation. Since bnxt uses
page pool frags and HDS by default, the rx-copybreak doesn't
buy us anything. The extra pressure on slab causes overload
on pre-sheaves kernels on modern AMD platforms.
In synthetic testing on net-next this patch shows little difference
but I think copybreak is "obvious waste" at this point.
Default rx-copybreak threshold to 0 / disabled.
The "copybreak" defines are really the size bounds for the Rx header
buffer. Rename them.
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Link: https://patch.msgid.link/20260602003759.1545645-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/ethernet/broadcom/bnxt/bnxt.c | 6 | ||||
| -rw-r--r-- | drivers/net/ethernet/broadcom/bnxt/bnxt.h | 4 | ||||
| -rw-r--r-- | drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 4 |
3 files changed, 7 insertions, 7 deletions
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index d4f93e62f583..3587f39202d2 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -4846,11 +4846,11 @@ static void bnxt_init_ring_params(struct bnxt *bp) { unsigned int rx_size; - bp->rx_copybreak = BNXT_DEFAULT_RX_COPYBREAK; + bp->rx_copybreak = 0; /* rx-copybreak disabled by default */ /* Try to fit 4 chunks into a 4k page */ rx_size = SZ_1K - NET_SKB_PAD - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - bp->dev->cfg->hds_thresh = max(BNXT_DEFAULT_RX_COPYBREAK, rx_size); + bp->dev->cfg->hds_thresh = max(BNXT_MIN_RX_HDR_BUF, rx_size); } /* bp->rx_ring_size, bp->tx_ring_size, dev->mtu, BNXT_FLAG_{G|L}RO flags must @@ -4911,7 +4911,7 @@ void bnxt_set_ring_params(struct bnxt *bp) ALIGN(max(NET_SKB_PAD, XDP_PACKET_HEADROOM), 8) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); } else { - rx_size = max3(BNXT_DEFAULT_RX_COPYBREAK, + rx_size = max3(BNXT_MIN_RX_HDR_BUF, bp->rx_copybreak, bp->dev->cfg_pending->hds_thresh); rx_size = SKB_DATA_ALIGN(rx_size + NET_IP_ALIGN); diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h index 61c847b36b9f..1920a161841e 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h @@ -36,8 +36,8 @@ #include <linux/firmware/broadcom/tee_bnxt_fw.h> #endif -#define BNXT_DEFAULT_RX_COPYBREAK 256 -#define BNXT_MAX_RX_COPYBREAK 1024 +#define BNXT_MIN_RX_HDR_BUF 256 +#define BNXT_MAX_RX_HDR_BUF 1024 extern struct list_head bnxt_block_cb_list; diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c index 9b14134d62d2..edafa79f636c 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c @@ -4594,7 +4594,7 @@ static int bnxt_set_tunable(struct net_device *dev, switch (tuna->id) { case ETHTOOL_RX_COPYBREAK: rx_copybreak = *(u32 *)data; - if (rx_copybreak > BNXT_MAX_RX_COPYBREAK) + if (rx_copybreak > BNXT_MAX_RX_HDR_BUF) return -ERANGE; if (rx_copybreak != bp->rx_copybreak) { if (netif_running(dev)) @@ -5172,7 +5172,7 @@ static int bnxt_run_loopback(struct bnxt *bp) cpr = &rxr->bnapi->cp_ring; if (bp->flags & BNXT_FLAG_CHIP_P5_PLUS) cpr = rxr->rx_cpr; - pkt_size = min(bp->dev->mtu + ETH_HLEN, max(BNXT_DEFAULT_RX_COPYBREAK, + pkt_size = min(bp->dev->mtu + ETH_HLEN, max(BNXT_MIN_RX_HDR_BUF, bp->rx_copybreak)); skb = netdev_alloc_skb(bp->dev, pkt_size); if (!skb) |