On Thu, 2008-05-29 at 16:34 +1000, Rusty Russell wrote: > On Tuesday 27 May 2008 21:06:26 Mark McLoughlin wrote: > > On Mon, 2008-05-26 at 17:42 +1000, Rusty Russell wrote: > > > If we fail to transmit a packet, we assume the queue is full and put > > > the skb into last_xmit_skb. However, if more space frees up before we > > > xmit it, we loop, and the result can be transmitting the same skb twice. > > > > > > Fix is simple: set skb to NULL if we've used it in some way, and check > > > before sending. > > Great! It's a corner case, but it's no more complicated to do it your way. > > Minor mod, I find it clearer to have the vi->last_xmit_skb = NULL; under > the branch: > > Subject: [PATCH] virtio_net: Delay dropping tx skbs > Date: Tue, 27 May 2008 12:06:26 +0100 > From: Mark McLoughlin <markmc@xxxxxxxxxx> > > Currently we drop the skb in start_xmit() if we have a > queued buffer and fail to transmit it. > > However, if we delay dropping it until we've stopped the > queue and enabled the tx notification callback, then there > is a chance space might become available for it. Hmm, we lost this one somewhere along the way ... Cheers, Mark. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
