netdev - [PATCH net-next] net: systemport: suppress warnings on failed Rx SKB allocations

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Message-Id: <1587683610-4342-1-git-send-email-opendmb@gmail.com>
Date:   Thu, 23 Apr 2020 16:13:30 -0700
From:   Doug Berger <opendmb@...il.com>
To:     Florian Fainelli <f.fainelli@...il.com>,
        "David S. Miller" <davem@...emloft.net>
Cc:     bcm-kernel-feedback-list@...adcom.com, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, Doug Berger <opendmb@...il.com>
Subject: [PATCH net-next] net: systemport: suppress warnings on failed Rx SKB allocations

The driver is designed to drop Rx packets and reclaim the buffers
when an allocation fails, and the network interface needs to safely
handle this packet loss. Therefore, an allocation failure of Rx
SKBs is relatively benign.

However, the output of the warning message occurs with a high
scheduling priority that can cause excessive jitter/latency for
other high priority processing.

This commit suppresses the warning messages to prevent scheduling
problems while retaining the failure count in the statistics of
the network interface.

Signed-off-by: Doug Berger <opendmb@...il.com>
---
 drivers/net/ethernet/broadcom/bcmsysport.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c
index af7ce5c5488c..ed12a0f894bf 100644
--- a/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/drivers/net/ethernet/broadcom/bcmsysport.c
@@ -664,7 +664,8 @@ static struct sk_buff *bcm_sysport_rx_refill(struct bcm_sysport_priv *priv,
 	dma_addr_t mapping;
 
 	/* Allocate a new SKB for a new packet */
-	skb = netdev_alloc_skb(priv->netdev, RX_BUF_LENGTH);
+	skb = __netdev_alloc_skb(priv->netdev, RX_BUF_LENGTH,
+				 GFP_ATOMIC | __GFP_NOWARN);
 	if (!skb) {
 		priv->mib.alloc_rx_buff_failed++;
 		netif_err(priv, rx_err, ndev, "SKB alloc failed\n");
-- 
2.7.4