[PATCH net-next v3 4/5] TEST ONLY: lan743x: skb_alloc failure test
From: Sven Van Asbroeck <hidden>
Date: 2021-02-16 01:10:03
Also in:
lkml
Subsystem:
microchip lan743x ethernet driver, networking drivers, the rest · Maintainers:
Bryan Whitehead, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Sven Van Asbroeck <redacted> Simulate low-memory in lan743x_rx_allocate_skb(): fail 10 allocations in a row in every 100. Signed-off-by: Sven Van Asbroeck <redacted> --- To: Bryan Whitehead <bryan.whitehead@microchip.com> To: UNGLinuxDriver@microchip.com To: "David S. Miller" <davem@davemloft.net> To: Jakub Kicinski <kuba@kernel.org> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Alexey Denisov <redacted> Cc: Sergej Bauer <redacted> Cc: Tim Harvey <tharvey@gateworks.com> Cc: Anders Rønningen <redacted> Cc: Hillf Danton <redacted> Cc: Christoph Hellwig <hch@lst.de> Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com> Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org drivers/net/ethernet/microchip/lan743x_main.c | 21 +++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c
index 90738ec5e7ec..6e1b3c996bd7 100644
--- a/drivers/net/ethernet/microchip/lan743x_main.c
+++ b/drivers/net/ethernet/microchip/lan743x_main.c@@ -1963,7 +1963,20 @@ static void lan743x_rx_update_tail(struct lan743x_rx *rx, int index) index); } -static int lan743x_rx_init_ring_element(struct lan743x_rx *rx, int index) +static struct sk_buff * +lan743x_alloc_skb(struct net_device *netdev, int length, bool can_fail) +{ + static int rx_alloc; + int counter = rx_alloc++ % 100; + + if (can_fail && counter >= 20 && counter < 30) + return NULL; + + return __netdev_alloc_skb(netdev, length, GFP_ATOMIC | GFP_DMA); +} + +static int +lan743x_rx_init_ring_element(struct lan743x_rx *rx, int index, bool can_fail) { struct net_device *netdev = rx->adapter->netdev; struct device *dev = &rx->adapter->pdev->dev;
@@ -1977,7 +1990,7 @@ static int lan743x_rx_init_ring_element(struct lan743x_rx *rx, int index) descriptor = &rx->ring_cpu_ptr[index]; buffer_info = &rx->buffer_info[index]; - skb = __netdev_alloc_skb(netdev, buffer_length, GFP_ATOMIC | GFP_DMA); + skb = lan743x_alloc_skb(netdev, buffer_length, can_fail); if (!skb) return -ENOMEM; dma_ptr = dma_map_single(dev, skb->data, buffer_length, DMA_FROM_DEVICE);
@@ -2139,7 +2152,7 @@ static int lan743x_rx_process_buffer(struct lan743x_rx *rx) /* save existing skb, allocate new skb and map to dma */ skb = buffer_info->skb; - if (lan743x_rx_init_ring_element(rx, rx->last_head)) { + if (lan743x_rx_init_ring_element(rx, rx->last_head, true)) { /* failed to allocate next skb. * Memory is very low. * Drop this packet and reuse buffer.
@@ -2344,7 +2357,7 @@ static int lan743x_rx_ring_init(struct lan743x_rx *rx) rx->last_head = 0; for (index = 0; index < rx->ring_size; index++) { - ret = lan743x_rx_init_ring_element(rx, index); + ret = lan743x_rx_init_ring_element(rx, index, false); if (ret) goto cleanup; }
--
2.17.1