Re: [PATCH net-next] net: mana: Force full-page RX buffers for 4K page size on specific systems.
From: Paolo Abeni <pabeni@redhat.com>
Date: 2026-03-03 11:56:41
Also in:
linux-hyperv, linux-rdma, lkml
On 2/27/26 11:15 AM, Dipayaan Roy wrote:
quoted hunk ↗ jump to hunk
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c index 91c418097284..a53a8921050b 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_en.c +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c@@ -748,6 +748,26 @@ static void *mana_get_rxbuf_pre(struct mana_rxq *rxq, dma_addr_t *da) return va; } +static inline bool +mana_use_single_rxbuf_per_page(struct mana_port_context *apc, u32 mtu) +{
I almost forgot: please avoid the 'inline' keyword in .c files. This is function used only once, should be inlined by the compiler anyway.
+ struct gdma_context *gc = apc->ac->gdma_dev->gdma_context; + + /* On some systems with 4K PAGE_SIZE, page_pool RX fragments can + * trigger a throughput regression. Hence forces one RX buffer per page + * to avoid the fragment allocation/refcounting overhead in the RX + * refill path for those processors only. + */ + if (gc->force_full_page_rx_buffer) + return true;
Side note: since you could keep the above flag up2date according to the current mtu and xdp configuration and just test it in the data path. /P