From: John Fastabend <john.r.fastabend@intel.com>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
Linux Kernel Network Developers <netdev@vger.kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Jamal Hadi Salim <jhs@mojatatu.com>
Subject: Re: [RFC Patch net-next] net_sched: make classifying lockless on ingress
Date: Fri, 20 Dec 2013 18:32:49 -0800 [thread overview]
Message-ID: <52B4FDD1.10608@intel.com> (raw)
In-Reply-To: <CAM_iQpXYpKE6zAAjFjzAW5KN=u7+C1gapz-bvkmVNFsNi+Jqmw@mail.gmail.com>
On 12/20/2013 4:24 PM, Cong Wang wrote:
> On Fri, Dec 20, 2013 at 4:08 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
>> On Fri, 2013-12-20 at 15:57 -0800, Cong Wang wrote:
>>
>>> Just push the lock down to ->enqueue() ? Since ingress qdisc is classless
>>> and its ->dequeue() is nop.
>>
>>
>> https://github.com/jrfastab/Linux-Kernel-QOS
>>
>> https://github.com/jrfastab/Linux-Kernel-QOS/commit/67746f95acd77cf15d7ce34f644b76058ce19813
>>
>
> It's a nice idea to introduce a ->prequeue().
>
> And so brave to play with RCU on singly linked list... maybe I can
> just steal the ->prequeue() piece. John? :-D
If you only steal the prequeue piece then you don't solve the lock
contention part so I don't think it helps. At which point I suspect
you might as well use one of the existing qdiscs not designed for
multiqueue nics.
>
> BTW, the last commit is about 5 months ago...
Yeah well I imagined I would write a rate limiting qdisc to use
this infrastructure. Jamal hinted at using a systolic processes
for this. But I work on this when I have time and have been
busy the last few months with other things unfortunately.
> --
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>
next prev parent reply other threads:[~2013-12-21 2:33 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-20 23:28 [RFC Patch net-next] net_sched: make classifying lockless on ingress Cong Wang
2013-12-20 23:49 ` Eric Dumazet
2013-12-20 23:57 ` Cong Wang
2013-12-21 0:08 ` Eric Dumazet
2013-12-21 0:24 ` Cong Wang
2013-12-21 2:32 ` John Fastabend [this message]
2013-12-21 22:11 ` Jamal Hadi Salim
2013-12-21 23:09 ` John Fastabend
2013-12-22 16:01 ` Jamal Hadi Salim
2013-12-24 0:56 ` Cong Wang
2013-12-24 6:08 ` John Fastabend
2013-12-26 12:02 ` Jamal Hadi Salim
2013-12-21 1:09 ` John Fastabend
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