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: Ivan Babrou <[email protected]> Acked-by: Edward Cree <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
matttbe · Jan 23, 2021 · e26ca4b · e26ca4b
1 parent e7ed11e
commit e26ca4b
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/drivers/net/ethernet/sfc/efx_channels.c b/drivers/net/ethernet/sfc/efx_channels.c
@@ -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)