On Saturday 14 June 2008 00:14:00 Mark McLoughlin wrote: > 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 ... Good catch. Looks like it got folded, but pre-folded version got merged. Sorry, I've restored it to my series. Thanks, Rusty. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
