On Fri, 2009-05-29 at 23:44 +0930, Rusty Russell wrote: > This patch adds skb_orphan to the start of dev_hard_start_xmit(): it > can be premature in the NETDEV_TX_BUSY case, but that's uncommon. Would it be possible to make the new skb_orphan() at the start of dev_hard_start_xmit() conditionally so that it is not executed for packets that are to be time stamped? As discussed before (http://article.gmane.org/gmane.linux.network/121378/), the skb->sk socket pointer is required for sending back the send time stamp from inside the device driver. Calling skb_orphan() unconditionally as in this patch would break the hardware time stamping of outgoing packets. This should work without much overhead (skb_tx() expands to a lookup of the skb_shared_info): if (!skb_tx(skb)->flags) skb_orphan(skb); Instead of looking at the individual skb_shared_tx "hardware" and "software" bits I'm just checking the whole byte here because it is shorter and perhaps faster. Semantically the result is the same. -- Best Regards, Patrick Ohly The content of this message is my personal opinion only and although I am an employee of Intel, the statements I make here in no way represent Intel's position on the issue, nor am I authorized to speak on behalf of Intel on this matter. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
