From: Jason Wang <jasowang@redhat.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Qin Chuanyu <qinchuanyu@huawei.com>,
davem@davemloft.net, "Michael S. Tsirkin" <mst@redhat.com>,
Anthony Liguori <anthony@codemonkey.ws>,
KVM list <kvm@vger.kernel.org>,
netdev@vger.kernel.org
Subject: Re: [PATCH] tun: use netif_receive_skb instead of netif_rx_ni
Date: Wed, 12 Feb 2014 15:38:50 +0800 [thread overview]
Message-ID: <52FB250A.9060702@redhat.com> (raw)
In-Reply-To: <1392186384.1752.9.camel@edumazet-glaptop2.roam.corp.google.com>
On 02/12/2014 02:26 PM, Eric Dumazet wrote:
> On Wed, 2014-02-12 at 13:50 +0800, Jason Wang wrote:
>> On 02/12/2014 01:47 PM, Eric Dumazet wrote:
>>> On Wed, 2014-02-12 at 13:28 +0800, Jason Wang wrote:
>>>
>>>> A question: without NAPI weight, could this starve other net devices?
>>> Not really, as net devices are serviced by softirq handler.
>>>
>>>
>> Yes, then the issue is tun could be starved by other net devices.
> How this patch changes anything to this 'problem' ?
>
> netif_rx_ni() can only be called if your process is not preempted by
> other high prio tasks/softirqs.
>
> If this process is scheduled on a cpu, then disabling bh to process
> _one_ packet wont fundamentally change dynamic of the system.
>
After looking at the code for a while, I agree it won't be a great change.
Thanks
next prev parent reply other threads:[~2014-02-12 7:38 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-11 14:25 [PATCH] tun: use netif_receive_skb instead of netif_rx_ni Qin Chuanyu
2014-02-11 15:24 ` Eric Dumazet
2014-02-11 15:47 ` Michael S. Tsirkin
2014-02-12 1:50 ` Qin Chuanyu
2014-02-16 13:03 ` Herbert Xu
2014-02-12 5:28 ` Jason Wang
2014-02-12 5:47 ` Eric Dumazet
2014-02-12 5:50 ` Jason Wang
2014-02-12 6:26 ` Eric Dumazet
2014-02-12 7:38 ` Jason Wang [this message]
2014-02-12 6:46 ` Qin Chuanyu
2014-02-12 7:40 ` Jason Wang
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