Re: [PATCH net 3/9] virtio-net: fix page miscount during XDP linearizing

From: Jason Wang
Date: Sun Dec 25 2016 - 21:30:36 EST

On 2016å12æ23æ 23:54, John Fastabend wrote:
On 16-12-23 06:37 AM, Jason Wang wrote:
We don't put page during linearizing, the would cause leaking when
xmit through XDP_TX or the packet exceeds PAGE_SIZE. Fix them by
put page accordingly. Also decrease the number of buffers during
linearizing to make sure caller can free buffers correctly when packet
exceeds PAGE_SIZE. With this patch, we won't get OOM after linearize
huge number of packets.

Cc: John Fastabend <john.r.fastabend@xxxxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
Thanks! looks good. By the way do you happen to have any actual
configuration where this path is hit? I obviously didn't test this
very long other than a quick test with my hacked vhost driver.

Acked-by: John Fastabend <john.r.fastabend@xxxxxxxxx>

Yes, I have. Just increase the MTU above 1500 for both virtio and tap and produce some traffic with size which will lead underestimated of rxbuf.