[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CAL8zT=huqtqBKzH3DDwid_C8jH16SH=kjYEK6zjxp_spfnLxXA@mail.gmail.com>
Date: Thu, 14 Jun 2012 16:14:53 +0200
From: Jean-Michel Hautbois <jhautbois@...il.com>
To: Eric Dumazet <eric.dumazet@...il.com>
Cc: netdev <netdev@...r.kernel.org>
Subject: Re: Regression on TX throughput when using bonding
2012/6/14 Jean-Michel Hautbois <jhautbois@...il.com>:
> 2012/6/14 Eric Dumazet <eric.dumazet@...il.com>:
>> On Thu, 2012-06-14 at 11:22 +0200, Eric Dumazet wrote:
>>
>>> So you are saying that if you make skb_orphan_try() doing nothing, it
>>> solves your problem ?
>>
>> It probably does, if your application does an UDP flood, trying to send
>> more than the link bandwidth. I guess only benchmarks workloads ever try
>> to do that.
>>
>> bonding has no way to give congestion back, it has no Qdisc by default.
>>
>> We probably can defer the skb_orphan_try() for bonding master, a bit
>> like the IFF_XMIT_DST_RELEASE
>>
>> drivers/net/bonding/bond_main.c | 2 +-
>> include/linux/if.h | 3 +++
>> net/core/dev.c | 5 +++--
>> 3 files changed, 7 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>> index 2ee8cf9..1b1e9c8 100644
>> --- a/drivers/net/bonding/bond_main.c
>> +++ b/drivers/net/bonding/bond_main.c
>> @@ -4343,7 +4343,7 @@ static void bond_setup(struct net_device *bond_dev)
>> bond_dev->tx_queue_len = 0;
>> bond_dev->flags |= IFF_MASTER|IFF_MULTICAST;
>> bond_dev->priv_flags |= IFF_BONDING;
>> - bond_dev->priv_flags &= ~(IFF_XMIT_DST_RELEASE | IFF_TX_SKB_SHARING);
>> + bond_dev->priv_flags &= ~(IFF_XMIT_DST_RELEASE | IFF_TX_SKB_SHARING | IFF_XMIT_ORPHAN);
>>
>> /* At first, we block adding VLANs. That's the only way to
>> * prevent problems that occur when adding VLANs over an
>> diff --git a/include/linux/if.h b/include/linux/if.h
>> index f995c66..a788e7b 100644
>> --- a/include/linux/if.h
>> +++ b/include/linux/if.h
>> @@ -81,6 +81,9 @@
>> #define IFF_UNICAST_FLT 0x20000 /* Supports unicast filtering */
>> #define IFF_TEAM_PORT 0x40000 /* device used as team port */
>> #define IFF_SUPP_NOFCS 0x80000 /* device supports sending custom FCS */
>> +#define IFF_XMIT_ORPHAN 0x100000 /* dev_hard_start_xmit() is allowed to
>> + * orphan skb
>> + */
>>
>>
>> #define IF_GET_IFACE 0x0001 /* for querying only */
>> diff --git a/net/core/dev.c b/net/core/dev.c
>> index cd09819..3435463 100644
>> --- a/net/core/dev.c
>> +++ b/net/core/dev.c
>> @@ -2193,7 +2193,8 @@ int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
>> if (!list_empty(&ptype_all))
>> dev_queue_xmit_nit(skb, dev);
>>
>> - skb_orphan_try(skb);
>> + if (dev->priv_flags & IFF_XMIT_ORPHAN)
>> + skb_orphan_try(skb);
>>
>> features = netif_skb_features(skb);
>>
>> @@ -5929,7 +5930,7 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
>> INIT_LIST_HEAD(&dev->napi_list);
>> INIT_LIST_HEAD(&dev->unreg_list);
>> INIT_LIST_HEAD(&dev->link_watch_list);
>> - dev->priv_flags = IFF_XMIT_DST_RELEASE;
>> + dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_ORPHAN;
>> setup(dev);
>>
>> dev->num_tx_queues = txqs;
>>
>>
>
> It works
For your information :
~# tc -s -d qdisc show dev eth1 > before_tc && sleep 10 && tc -s -d
qdisc show dev eth1 > after_tc && ./beforeafter before_tc after_tc
qdisc mq 0: root
Sent 3185900568 bytes 788681 pkt (dropped 0, overlimits 0 requeues 620)
backlog 0b 0p requeues 620
As you can see, 2.5Gbps without any difficulties :).
Thanks,
JM
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists