From: Sowmini Varadhan <sowmini.varadhan@oracle.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: davem@davemloft.net, raghuram.kothakota@oracle.com,
netdev@vger.kernel.org
Subject: Re: [PATCH net-next 2/2] sunvnet: vnet_start_xmit() must hold a refcnt on port.
Date: Wed, 01 Oct 2014 16:19:41 -0400 [thread overview]
Message-ID: <542C61DD.8010504@oracle.com> (raw)
In-Reply-To: <1412194526.16704.61.camel@edumazet-glaptop2.roam.corp.google.com>
On 10/01/2014 04:15 PM, Eric Dumazet wrote:
> On Wed, 2014-10-01 at 15:44 -0400, Sowmini Varadhan wrote:
>> On (10/01/14 12:05), Eric Dumazet wrote:
>>>
>>> Hmpff... This calls for rcu protection here !
>>>
>>
>> I did consider that, but given that the lists containing the ports are
>> accessed in multiple contexts, some of which can sleep, and given that
>> the vnet port is similar in spirit to the net_device, I followed the
>> net_device model of dev_put etc.
>
> dev_put() uses per cpu variables, an order of magnitude faster than a
> atomic put/get :(
I could make this a per-cpu variable, it would not be too hard to change
vnet_put/hold etc. That's not a problem.
--Sowmini
next prev parent reply other threads:[~2014-10-01 20:19 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-01 18:56 [PATCH net-next 2/2] sunvnet: vnet_start_xmit() must hold a refcnt on port Sowmini Varadhan
2014-10-01 19:05 ` Eric Dumazet
2014-10-01 19:44 ` Sowmini Varadhan
2014-10-01 20:15 ` Eric Dumazet
2014-10-01 20:19 ` Sowmini Varadhan [this message]
2014-10-01 20:24 ` David Miller
2014-10-01 19:06 ` David L Stevens
2014-10-01 19:23 ` Sowmini Varadhan
2014-10-01 19:31 ` David L Stevens
2014-10-01 19:52 ` David Miller
2014-10-02 3:36 ` Raghuram Kothakota
2014-10-02 3:23 ` Raghuram Kothakota
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