From: Richard Davies <richard.j.davies@gmail•com>
To: Chris Webb <chris@arachsys•com>
Cc: netdev@vger•kernel.org, qemu-devel@nongnu•org,
Jason Wang <jasowang@redhat•com>, Arnd Bergmann <arnd@arndb•de>,
Michael Tsirkin <mst@redhat•com>
Subject: Re: Slow inbound traffic on macvtap interfaces
Date: Thu, 30 Aug 2012 09:20:57 +0100 [thread overview]
Message-ID: <20120830082057.GA18072@alpha.arachsys.com> (raw)
In-Reply-To: <20120829175256.GC3529@arachsys.com>
Chris Webb wrote:
> I found that on my laptop, the single change of host kernel config
>
> -CONFIG_INTEL_IDLE=y
> +# CONFIG_INTEL_IDLE is not set
>
> is sufficient to turn transfers into guests from slow to full wire speed
I am not deep enough in this code to write a patch, but I wonder if
macvtap_forward in macvtap.c is missing a call to kill_fasync, which I
understand is used to signal to interested processes when data arrives?
Here is the end of macvtap_forward:
skb_queue_tail(&q->sk.sk_receive_queue, skb);
wake_up_interruptible_poll(sk_sleep(&q->sk), POLLIN | POLLRDNORM | POLLRDBAND);
return NET_RX_SUCCESS;
Compared to this end of tun_net_xmit in tun.c:
/* Enqueue packet */
skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
/* Notify and wake up reader process */
if (tun->flags & TUN_FASYNC)
kill_fasync(&tun->fasync, SIGIO, POLL_IN);
wake_up_interruptible_poll(&tun->wq.wait, POLLIN |
POLLRDNORM | POLLRDBAND);
return NETDEV_TX_OK;
Richard.
next prev parent reply other threads:[~2012-08-30 8:49 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-16 9:20 Slow inbound traffic on macvtap interfaces Chris Webb
2012-08-16 11:42 ` Michael S. Tsirkin
2012-08-16 14:27 ` Chris Webb
2012-08-16 15:36 ` Michael S. Tsirkin
2012-09-19 15:11 ` Macvtap bug: contractor wanted Richard Davies, Chris Webb
2012-09-19 17:54 ` David Miller
2012-08-29 17:52 ` Slow inbound traffic on macvtap interfaces Chris Webb
2012-08-30 8:20 ` Richard Davies [this message]
2012-08-30 8:44 ` Michael S. Tsirkin
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