diff mbox series

[v4,6/6] igb: avoid transmit queue timeout in xdp path

Message ID 20201111170453.32693-7-sven.auhagen@voleatech.de
State Under Review
Delegated to: Anthony Nguyen
Headers show
Series igb: xdp patches followup | expand

Commit Message

Sven Auhagen Nov. 11, 2020, 5:04 p.m. UTC
From: Sven Auhagen <sven.auhagen@voleatech.de>

Since we share the transmit queue with the network stack,
it is possible that we run into a transmit queue timeout.
This will reset the queue.
This happens under high load when XDP is using the
transmit queue pretty much exclusively.

netdev_start_xmit() sets the trans_start variable of the
transmit queue to jiffies which is later utilized by dev_watchdog(),
so to avoid timeout, let stack know that XDP xmit happened by
bumping the trans_start within XDP Tx routines to jiffies.

Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Sven Auhagen <sven.auhagen@voleatech.de>
---
 drivers/net/ethernet/intel/igb/igb_main.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Penigalapati, Sandeep Nov. 24, 2020, 2:49 p.m. UTC | #1
From: sven.auhagen@voleatech.de <sven.auhagen@voleatech.de> 
Sent: Wednesday, November 11, 2020 10:35 PM
To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Fijalkowski, Maciej <maciej.fijalkowski@intel.com>; kuba@kernel.org
Cc: davem@davemloft.net; intel-wired-lan@lists.osuosl.org; netdev@vger.kernel.org; nhorman@redhat.com; sassmann@redhat.com; Penigalapati, Sandeep <sandeep.penigalapati@intel.com>; brouer@redhat.com; pmenzel@molgen.mpg.de
Subject: [PATCH v4 6/6] igb: avoid transmit queue timeout in xdp path

From: Sven Auhagen <sven.auhagen@voleatech.de>

Since we share the transmit queue with the network stack, it is possible that we run into a transmit queue timeout.
This will reset the queue.
This happens under high load when XDP is using the transmit queue pretty much exclusively.

netdev_start_xmit() sets the trans_start variable of the transmit queue to jiffies which is later utilized by dev_watchdog(), so to avoid timeout, let stack know that XDP xmit happened by bumping the trans_start within XDP Tx routines to jiffies.

Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Sven Auhagen <sven.auhagen@voleatech.de>
---
 drivers/net/ethernet/intel/igb/igb_main.c | 5 +++++
 1 file changed, 5 insertions(+)

Tested-by: Sandeep Penigalapati <sandeep.penigalapati@intel.com>
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index b6c793441585..74f0f06bedff 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -2919,6 +2919,8 @@  static int igb_xdp_xmit_back(struct igb_adapter *adapter, struct xdp_buff *xdp)
 
 	nq = txring_txq(tx_ring);
 	__netif_tx_lock(nq, cpu);
+	/* Avoid transmit queue timeout since we share it with the slow path */
+	nq->trans_start = jiffies;
 	ret = igb_xmit_xdp_ring(adapter, tx_ring, xdpf);
 	__netif_tx_unlock(nq);
 
@@ -2951,6 +2953,9 @@  static int igb_xdp_xmit(struct net_device *dev, int n,
 	nq = txring_txq(tx_ring);
 	__netif_tx_lock(nq, cpu);
 
+	/* Avoid transmit queue timeout since we share it with the slow path */
+	nq->trans_start = jiffies;
+
 	for (i = 0; i < n; i++) {
 		struct xdp_frame *xdpf = frames[i];
 		int err;