From mboxrd@z Thu Jan  1 00:00:00 1970
From: Shirley Ma <mashirle@us.ibm.com>
Subject: Re: [PATCH 2/2] virtio_net: remove send completion interrupts and
 avoid TX queue overrun through packet drop
Date: Thu, 17 Mar 2011 08:10:05 -0700
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Cc: "Michael S. Tsirkin" <mst@redhat.com>,
	David Miller <davem@davemloft.net>, kvm@vger.kernel.org,
	netdev@vger.kernel.org
To: Rusty Russell <rusty@rustcorp.com.au>
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On Thu, 2011-03-17 at 15:40 +1030, Rusty Russell wrote:
> This is fascinating... and deeply weird.
> 
> OK, what's the difference between calling xmit_skb and ignoring
> failure,
> and this patch which figures out it's going to fail before calling
> xmit_skb?
> 
> ie. what if you *just* delete this:

Somehow what was in my mind, add_buf is more expensive than simply
checked ring capacity. I retest it with your and Michael's suggestion
here.

Thanks
Shirley