[PATCH 2/9] aoe: print warning regarding a common reason for dropped transmits

From: Ed Cashin
Date: Mon Oct 15 2012 - 21:42:37 EST


Dropped transmits are not common, but when they do occur, increasing
the transmit queue length often helps.

Signed-off-by: Ed Cashin <ecashin@xxxxxxxxxx>
---
drivers/block/aoe/aoenet.c | 11 +++++++++--
1 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/block/aoe/aoenet.c b/drivers/block/aoe/aoenet.c
index 162c647..a1bb692 100644
--- a/drivers/block/aoe/aoenet.c
+++ b/drivers/block/aoe/aoenet.c
@@ -50,7 +50,11 @@ __setup("aoe_iflist=", aoe_iflist_setup);
static spinlock_t txlock;
static struct sk_buff_head skbtxq;

-/* enters with txlock held */
+/* enters with txlock held
+ *
+ * Use __must_hold(&txlock) for sparse when upcoming patch adds it to
+ * compiler.h.
+ */
static int
tx(void)
{
@@ -58,7 +62,10 @@ tx(void)

while ((skb = skb_dequeue(&skbtxq))) {
spin_unlock_irq(&txlock);
- dev_queue_xmit(skb);
+ if (dev_queue_xmit(skb) == NET_XMIT_DROP && net_ratelimit())
+ pr_warn("aoe: packet could not be sent on %s. %s\n",
+ skb->dev ? skb->dev->name : "netif",
+ "consider increasing tx_queue_len");
spin_lock_irq(&txlock);
}
return 0;
--
1.7.1

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