Re: [PATCH] net: remove skb_orphan_try()

[David Miller <davem@davemloft.net>]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 14 Jun 2012 18:42:44 +0200

> [PATCH] net: remove skb_orphan_try()
> 
> Orphaning skb in dev_hard_start_xmit() makes bonding behavior
> unfriendly for applications sending big UDP bursts : Once packets
> pass the bonding device and come to real device, they might hit a full
> qdisc and be dropped. Without orphaning, the sender is automatically
> throttled because sk->sk_wmemalloc reaches sk->sk_sndbuf (assuming
> sk_sndbuf is not too big)
> 
> We could try to defer the orphaning adding another test in
> dev_hard_start_xmit(), but all this seems of little gain,
> now that BQL tends to make packets more likely to be parked
> in Qdisc queues instead of NIC TX ring, in cases where performance
> matters.
> 
> Reverts commits :
> fc6055a5ba31 net: Introduce skb_orphan_try()
> 87fd308cfc6b net: skb_tx_hash() fix relative to skb_orphan_try()
> and removes SKBTX_DRV_NEEDS_SK_REF flag
> 
> Reported-and-bisected-by: Jean-Michel Hautbois <jhautbois@gmail.com>
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Applied, thanks Eric.