similar to: [PATCH] netback: add ethtool stat to track copied skbs

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Dear list members (especially Xen network wizards), I''m using the netfilter_queue mechanism to modify packets on the wire that are sent from one domU to another while they travel over the dom0 bridge. This has worked fine as long as I was tinkering with UDP packets only - but when I try to reinject TCP frames with an increased length, I run into a BUG() because

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We check for finished xmit skbs on every xmit, or on a timer (unless the host promises to force an interrupt when the xmit ring is empty). This can penalize userspace tasks which fill their sockbuf. Not much difference with TSO, but measurable with large numbers of packets. There are a finite number of packets which can be in the transmission queue. We could fire the timer more than every

We check for finished xmit skbs on every xmit, or on a timer (unless the host promises to force an interrupt when the xmit ring is empty). This can penalize userspace tasks which fill their sockbuf. Not much difference with TSO, but measurable with large numbers of packets. There are a finite number of packets which can be in the transmission queue. We could fire the timer more than every

On Thursday 01 May 2008 00:31:46 Mark McLoughlin wrote: > virtio_net currently only frees old transmit skbs just > before queueing new ones. If the queue is full, it then > enables interrupts and waits for notification that more > work has been performed. Hi Mark, This patch is fine, but it's better to do it from skb_xmit_done(). Of course, this is usually called from an

On Thursday 01 May 2008 00:31:46 Mark McLoughlin wrote: > virtio_net currently only frees old transmit skbs just > before queueing new ones. If the queue is full, it then > enables interrupts and waits for notification that more > work has been performed. Hi Mark, This patch is fine, but it's better to do it from skb_xmit_done(). Of course, this is usually called from an

Hi Keir: These two patches remove the need for netloop by performing the copying in netback and only if it is necessary. The rationale is that most packets will be processed without delay allowing them to be freed without copying at all. So instead of copying every packet destined to dom0 we''ll only copy those that linger longer than a specified amount of time (currently 0.5s). As it