From: Eric Dumazet <eric.dumazet@gmail.com>
To: Jarek Poplawski <jarkao2@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>,
Tom Herbert <therbert@google.com>,
Linux Netdev List <netdev@vger.kernel.org>
Subject: Re: [PATCH net-next-2.6] net: Xmit Packet Steering (XPS)
Date: Fri, 20 Nov 2009 23:21:08 +0100 [thread overview]
Message-ID: <4B071654.6040300@gmail.com> (raw)
In-Reply-To: <20091120220851.GA4717@ami.dom.local>
Jarek Poplawski a écrit :
> On Fri, Nov 20, 2009 at 10:43:55PM +0100, Eric Dumazet wrote:
>>> Hmm... Actually, why did I have to do lockdep's job...
>> In fact I could not find why irq masking is necessary, and lockdep is
>> fine with my code and my testings. Care to explain what problem you spotted ?
>>
>
> CPU1 CPU2
> net_rx_action() net_rx_action()
> xps_flush() xps_flush()
> q = &per_cpu(xps_pcpu_queue, cpu2) q = &per_cpu(xps_pcpu_queue, cpu1)
> spin_lock(&q->list.lock of cpu2) spin_lock(&q->list.lock of cpu1)
>
> <IPI> <IPI>
> remote_free_skb_list() remote_free_skb_list()
> waiting on spin_lock(&q->list.lock of cpu1) waiting on spin_lock(&q->list.lock of cpu2)
>
>
> IPIs triggerered e.g. by CPU3 (or/and CPU4...) doing net_rx_action as well.
>
:) Now I am convinced :)
Thanks jarek
next prev parent reply other threads:[~2009-11-20 22:21 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-19 23:46 [PATCH net-next-2.6] net: Xmit Packet Steering (XPS) Eric Dumazet
2009-11-20 2:12 ` Changli Gao
2009-11-20 4:58 ` Eric Dumazet
2009-11-20 5:11 ` Changli Gao
2009-11-20 5:24 ` Eric Dumazet
2009-11-20 5:34 ` Changli Gao
2009-11-20 5:42 ` Eric Dumazet
2009-11-20 5:50 ` Changli Gao
[not found] ` <65634d660911191641o4210a797mf1e8168dd8dd8b60@mail.gmail.com>
2009-11-20 5:08 ` Eric Dumazet
2009-11-20 13:32 ` Jarek Poplawski
2009-11-20 14:45 ` Eric Dumazet
2009-11-20 20:04 ` Jarek Poplawski
2009-11-20 21:43 ` Eric Dumazet
2009-11-20 22:08 ` Jarek Poplawski
2009-11-20 22:21 ` Eric Dumazet [this message]
2009-11-20 20:51 ` Andi Kleen
2009-11-20 20:53 ` David Miller
2009-11-20 22:30 ` Eric Dumazet
2009-11-20 22:37 ` Andi Kleen
[not found] ` <65634d660911201642k3930dc78vd576e0e89dc0c794@mail.gmail.com>
2009-11-21 6:58 ` Eric Dumazet
2009-11-20 20:53 ` Jarek Poplawski
2009-11-20 21:35 ` Eric Dumazet
2009-11-20 21:43 ` Joe Perches
2009-11-20 21:49 ` David Miller
2009-11-20 22:01 ` Eric Dumazet
2009-11-20 22:34 ` David Miller
2009-11-20 22:32 ` David Miller
2009-11-20 22:36 ` Eric Dumazet
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