Commit 39f8fcda authored by David Wei's avatar David Wei Committed by Jakub Kicinski
Browse files

bnxt: fill data page pool with frags if PAGE_SIZE > BNXT_RX_PAGE_SIZE 



The data page pool always fills the HW rx ring with pages. On arm64 with
64K pages, this will waste _at least_ 32K of memory per entry in the rx
ring.

Fix by fragmenting the pages if PAGE_SIZE > BNXT_RX_PAGE_SIZE. This
makes the data page pool the same as the header pool.

Tested with iperf3 with a small (64 entries) rx ring to encourage buffer
circulation.

Fixes: cd1fafe7 ("eth: bnxt: add support rx side device memory TCP")
Reviewed-by: default avatarMichael Chan <michael.chan@broadcom.com>
Signed-off-by: default avatarDavid Wei <dw@davidwei.uk>
Link: https://patch.msgid.link/20250812182907.1540755-1-dw@davidwei.uk


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent b2cafefa

drivers/net/ethernet/broadcom/bnxt/bnxt.c

+9 −3
Original line number Diff line number Diff line
@@ -926,15 +926,21 @@ static struct page *__bnxt_alloc_rx_page(struct bnxt *bp, dma_addr_t *mapping, 


static netmem_ref __bnxt_alloc_rx_netmem(struct bnxt *bp, dma_addr_t *mapping,

					 struct bnxt_rx_ring_info *rxr,

					 unsigned int *offset,

					 gfp_t gfp)

{

	netmem_ref netmem;



	if (PAGE_SIZE > BNXT_RX_PAGE_SIZE) {

		netmem = page_pool_alloc_frag_netmem(rxr->page_pool, offset, BNXT_RX_PAGE_SIZE, gfp);

	} else {

		netmem = page_pool_alloc_netmems(rxr->page_pool, gfp);

		*offset = 0;

	}

	if (!netmem)

		return 0;



	*mapping = page_pool_get_dma_addr_netmem(netmem);

	*mapping = page_pool_get_dma_addr_netmem(netmem) + *offset;

	return netmem;

}
@@ -1029,7 +1035,7 @@ static int bnxt_alloc_rx_netmem(struct bnxt *bp, struct bnxt_rx_ring_info *rxr, 
	dma_addr_t mapping;

	netmem_ref netmem;



	netmem = __bnxt_alloc_rx_netmem(bp, &mapping, rxr, gfp);

	netmem = __bnxt_alloc_rx_netmem(bp, &mapping, rxr, &offset, gfp);

	if (!netmem)

		return -ENOMEM;