From: Eric Dumazet
Date: Wed, 07 Dec 2016 09:19:33 -0800
> From: Eric Dumazet
>
> Under UDP flood, many softirq producers try to add packets to
> UDP receive queue, and one user thread is burning one cpu trying
> to dequeue packets as fast as possible.
>
> Two parts of the per packet cost are
On Thu, 2016-12-08 at 07:36 -0800, Rick Jones wrote:
> On 12/08/2016 07:30 AM, Eric Dumazet wrote:
> > On Thu, 2016-12-08 at 10:46 +0100, Jesper Dangaard Brouer wrote:
> >
> >> Hmmm... I'm not thrilled to have such heuristics, that change memory
> >> behavior when half of the queue size (sk->sk_rcv
On 12/08/2016 07:30 AM, Eric Dumazet wrote:
On Thu, 2016-12-08 at 10:46 +0100, Jesper Dangaard Brouer wrote:
Hmmm... I'm not thrilled to have such heuristics, that change memory
behavior when half of the queue size (sk->sk_rcvbuf) is reached.
Well, copybreak drivers do that unconditionally, e
On Thu, 2016-12-08 at 10:46 +0100, Jesper Dangaard Brouer wrote:
> Hmmm... I'm not thrilled to have such heuristics, that change memory
> behavior when half of the queue size (sk->sk_rcvbuf) is reached.
Well, copybreak drivers do that unconditionally, even under no stress at
all, you really shoul
On Wed, 07 Dec 2016 09:19:33 -0800
Eric Dumazet wrote:
> From: Eric Dumazet
>
> Under UDP flood, many softirq producers try to add packets to
> UDP receive queue, and one user thread is burning one cpu trying
> to dequeue packets as fast as possible.
>
> Two parts of the per packet cost are :
On Wed, 2016-12-07 at 09:19 -0800, Eric Dumazet wrote:
> From: Eric Dumazet
> This patch gave me about 5 % increase in throughput in my tests.
>
BTW, this reduces the gap with GRO being on or off for me :
mlx4 drivers has a copybreak feature when GRO is off :
Packets below 256 bytes are simpl
From: Eric Dumazet
Under UDP flood, many softirq producers try to add packets to
UDP receive queue, and one user thread is burning one cpu trying
to dequeue packets as fast as possible.
Two parts of the per packet cost are :
- copying payload from kernel space to user space,
- freeing memory pie
