John Fastabend
2017-Jan-02 22:43 UTC
[PATCH net 9/9] virtio-net: XDP support for small buffers
On 16-12-23 06:37 AM, Jason Wang wrote:> Commit f600b6905015 ("virtio_net: Add XDP support") leaves the case of > small receive buffer untouched. This will confuse the user who want to > set XDP but use small buffers. Other than forbid XDP in small buffer > mode, let's make it work. XDP then can only work at skb->data since > virtio-net create skbs during refill, this is sub optimal which could > be optimized in the future. > > Cc: John Fastabend <john.r.fastabend at intel.com> > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/net/virtio_net.c | 112 ++++++++++++++++++++++++++++++++++++----------- > 1 file changed, 87 insertions(+), 25 deletions(-) >Hi Jason, I was doing some more testing on this what do you think about doing this so that free_unused_bufs() handles the buffer free with dev_kfree_skb() instead of put_page in small receive mode. Seems more correct to me. diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 783e842..27ff76c 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1898,6 +1898,10 @@ static void free_receive_page_frags(struct virtnet_info *vi) static bool is_xdp_queue(struct virtnet_info *vi, int q) { + /* For small receive mode always use kfree_skb variants */ + if (!vi->mergeable_rx_bufs) + return false; + if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs)) return false; else if (q < vi->curr_queue_pairs) patch is untested just spotted doing code review. Thanks, John
Jason Wang
2017-Jan-03 06:16 UTC
[PATCH net 9/9] virtio-net: XDP support for small buffers
On 2017?01?03? 06:43, John Fastabend wrote:> On 16-12-23 06:37 AM, Jason Wang wrote: >> Commit f600b6905015 ("virtio_net: Add XDP support") leaves the case of >> small receive buffer untouched. This will confuse the user who want to >> set XDP but use small buffers. Other than forbid XDP in small buffer >> mode, let's make it work. XDP then can only work at skb->data since >> virtio-net create skbs during refill, this is sub optimal which could >> be optimized in the future. >> >> Cc: John Fastabend <john.r.fastabend at intel.com> >> Signed-off-by: Jason Wang <jasowang at redhat.com> >> --- >> drivers/net/virtio_net.c | 112 ++++++++++++++++++++++++++++++++++++----------- >> 1 file changed, 87 insertions(+), 25 deletions(-) >> > Hi Jason, > > I was doing some more testing on this what do you think about doing this > so that free_unused_bufs() handles the buffer free with dev_kfree_skb() > instead of put_page in small receive mode. Seems more correct to me. > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 783e842..27ff76c 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -1898,6 +1898,10 @@ static void free_receive_page_frags(struct virtnet_info *vi) > > static bool is_xdp_queue(struct virtnet_info *vi, int q) > { > + /* For small receive mode always use kfree_skb variants */ > + if (!vi->mergeable_rx_bufs) > + return false; > + > if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs)) > return false; > else if (q < vi->curr_queue_pairs) > > > patch is untested just spotted doing code review. > > Thanks, > JohnWe probably need a better name for this function. Acked-by: Jason Wang <jasowang at redhat.com>
John Fastabend
2017-Jan-03 16:40 UTC
[PATCH net 9/9] virtio-net: XDP support for small buffers
On 17-01-02 10:16 PM, Jason Wang wrote:> > > On 2017?01?03? 06:43, John Fastabend wrote: >> On 16-12-23 06:37 AM, Jason Wang wrote: >>> Commit f600b6905015 ("virtio_net: Add XDP support") leaves the case of >>> small receive buffer untouched. This will confuse the user who want to >>> set XDP but use small buffers. Other than forbid XDP in small buffer >>> mode, let's make it work. XDP then can only work at skb->data since >>> virtio-net create skbs during refill, this is sub optimal which could >>> be optimized in the future. >>> >>> Cc: John Fastabend <john.r.fastabend at intel.com> >>> Signed-off-by: Jason Wang <jasowang at redhat.com> >>> --- >>> drivers/net/virtio_net.c | 112 ++++++++++++++++++++++++++++++++++++----------- >>> 1 file changed, 87 insertions(+), 25 deletions(-) >>> >> Hi Jason, >> >> I was doing some more testing on this what do you think about doing this >> so that free_unused_bufs() handles the buffer free with dev_kfree_skb() >> instead of put_page in small receive mode. Seems more correct to me. >> >> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c >> index 783e842..27ff76c 100644 >> --- a/drivers/net/virtio_net.c >> +++ b/drivers/net/virtio_net.c >> @@ -1898,6 +1898,10 @@ static void free_receive_page_frags(struct virtnet_info >> *vi) >> >> static bool is_xdp_queue(struct virtnet_info *vi, int q) >> { >> + /* For small receive mode always use kfree_skb variants */ >> + if (!vi->mergeable_rx_bufs) >> + return false; >> + >> if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs)) >> return false; >> else if (q < vi->curr_queue_pairs) >> >> >> patch is untested just spotted doing code review. >> >> Thanks, >> John > > We probably need a better name for this function. > > Acked-by: Jason Wang <jasowang at redhat.com> >How about is_xdp_raw_buffer_queue()? I'll submit a proper patch today.
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