2021-03-04 14:36:10

by Coiby Xu

Subject: [PATCH v1 1/3] i40e: use minimal tx and rx pairs for kdump

Set the number of the MSI-X vectors to 1. When MSI-X is enabled,
it's not allowed to use more TC queue pairs than MSI-X vectors
(pf->num_lan_msix) exist. Thus the number of tx and rx pairs
(vsi->num_queue_pairs) will be equal to the number of MSI-X vectors,
i.e., 1.

Signed-off-by: Coiby Xu <[email protected]>
---
drivers/net/ethernet/intel/i40e/i40e_main.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 353deae139f9..77bf8c392750 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -6,6 +6,7 @@
#include <linux/pci.h>
#include <linux/bpf.h>
#include <generated/utsrelease.h>
+#include <linux/crash_dump.h>

/* Local includes */
#include "i40e.h"
@@ -15485,6 +15486,14 @@ static int i40e_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
if (err)
goto err_switch_setup;

+ /* Reduce tx and rx pairs for kdump
+ * When MSI-X is enabled, it's not allowed to use more TC queue
+ * pairs than MSI-X vectors (pf->num_lan_msix) exist. Thus
+ * vsi->num_queue_pairs will be equal to pf->num_lan_msix, i.e., 1.
+ */
+ if (is_kdump_kernel())
+ pf->num_lan_msix = 1;
+
pf->udp_tunnel_nic.set_port = i40e_udp_tunnel_set_port;
pf->udp_tunnel_nic.unset_port = i40e_udp_tunnel_unset_port;
pf->udp_tunnel_nic.flags = UDP_TUNNEL_NIC_INFO_MAY_SLEEP;
--
2.30.1

2021-04-22 21:02:36

by Switzer, David

Subject: RE: [PATCH v1 1/3] i40e: use minimal tx and rx pairs for kdump

>-----Original Message-----
>From: Coiby Xu <[email protected]>
>Sent: Wednesday, March 3, 2021 6:56 PM
>To: [email protected]
>Cc: [email protected]; [email protected]; Jakub Kicinski
><[email protected]>; Brandeburg, Jesse <[email protected]>; Nguyen,
>Anthony L <[email protected]>; David S. Miller
><[email protected]>; open list <[email protected]>
>Subject: [PATCH v1 1/3] i40e: use minimal tx and rx pairs for kdump
>
>Set the number of the MSI-X vectors to 1. When MSI-X is enabled, it's not allowed
>to use more TC queue pairs than MSI-X vectors
>(pf->num_lan_msix) exist. Thus the number of tx and rx pairs
>(vsi->num_queue_pairs) will be equal to the number of MSI-X vectors, i.e., 1.
>
>Signed-off-by: Coiby Xu <[email protected]>
>---
> drivers/net/ethernet/intel/i40e/i40e_main.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
Tested-by: Dave Switzer <[email protected]