Commit e26ca4b5 authored by Ivan Babrou's avatar Ivan Babrou Committed by Jakub Kicinski
Browse files

sfc: reduce the number of requested xdp ev queues 



Without this change the driver tries to allocate too many queues,
breaching the number of available msi-x interrupts on machines
with many logical cpus and default adapter settings:

Insufficient resources for 12 XDP event queues (24 other channels, max 32)

Which in turn triggers EINVAL on XDP processing:

sfc 0000:86:00.0 ext0: XDP TX failed (-22)

Signed-off-by: default avatarIvan Babrou <ivan@cloudflare.com>
Acked-by: default avatarEdward Cree <ecree.xilinx@gmail.com>
Link: https://lore.kernel.org/r/20210120212759.81548-1-ivan@cloudflare.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent e7ed11ee

drivers/net/ethernet/sfc/efx_channels.c

+4 −2
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include "rx_common.h"

#include "nic.h"

#include "sriov.h"

#include "workarounds.h"



/* This is the first interrupt mode to try out of:

 * 0 => MSI-X
@@ -137,6 +138,7 @@ static int efx_allocate_msix_channels(struct efx_nic *efx, 
{

	unsigned int n_channels = parallelism;

	int vec_count;

	int tx_per_ev;

	int n_xdp_tx;

	int n_xdp_ev;
@@ -149,9 +151,9 @@ static int efx_allocate_msix_channels(struct efx_nic *efx, 
	 * multiple tx queues, assuming tx and ev queues are both

	 * maximum size.

	 */



	tx_per_ev = EFX_MAX_EVQ_SIZE / EFX_TXQ_MAX_ENT(efx);

	n_xdp_tx = num_possible_cpus();

	n_xdp_ev = DIV_ROUND_UP(n_xdp_tx, EFX_MAX_TXQ_PER_CHANNEL);

	n_xdp_ev = DIV_ROUND_UP(n_xdp_tx, tx_per_ev);



	vec_count = pci_msix_vec_count(efx->pci_dev);

	if (vec_count < 0)