From: Ben Hutchings <bhutchings@solarflare.com> To: Jason Wang <jasowang@redhat.com> Cc: <mst@redhat.com>, <mashirle@us.ibm.com>, <krkumar2@in.ibm.com>, <habanero@linux.vnet.ibm.com>, <rusty@rustcorp.com.au>, <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <virtualization@lists.linux-foundation.org>, <edumazet@google.com>, <tahm@linux.vnet.ibm.com>, <jwhan@filewood.snu.ac.kr>, <davem@davemloft.net>, <akong@redhat.com>, <kvm@vger.kernel.org>, <sri@us.ibm.com> Subject: Re: [net-next RFC V5 5/5] virtio_net: support negotiating the number of queues through ctrl vq Date: Mon, 9 Jul 2012 21:13:23 +0100 [thread overview] Message-ID: <1341864803.2535.53.camel@bwh-desktop.uk.solarflarecom.com> (raw) In-Reply-To: <1341484194-8108-6-git-send-email-jasowang@redhat.com> On Thu, 2012-07-05 at 18:29 +0800, Jason Wang wrote: > This patch let the virtio_net driver can negotiate the number of queues it > wishes to use through control virtqueue and export an ethtool interface to let > use tweak it. > > As current multiqueue virtio-net implementation has optimizations on per-cpu > virtuqueues, so only two modes were support: > > - single queue pair mode > - multiple queue paris mode, the number of queues matches the number of vcpus > > The single queue mode were used by default currently due to regression of > multiqueue mode in some test (especially in stream test). > > Since virtio core does not support paritially deleting virtqueues, so during > mode switching the whole virtqueue were deleted and the driver would re-create > the virtqueues it would used. > > btw. The queue number negotiating were defered to .ndo_open(), this is because > only after feature negotitaion could we send the command to control virtqueue > (as it may also use event index). [...] > +static int virtnet_set_channels(struct net_device *dev, > + struct ethtool_channels *channels) > +{ > + struct virtnet_info *vi = netdev_priv(dev); > + u16 queues = channels->rx_count; > + unsigned status = VIRTIO_CONFIG_S_ACKNOWLEDGE | VIRTIO_CONFIG_S_DRIVER; > + > + if (channels->rx_count != channels->tx_count) > + return -EINVAL; [...] > +static void virtnet_get_channels(struct net_device *dev, > + struct ethtool_channels *channels) > +{ > + struct virtnet_info *vi = netdev_priv(dev); > + > + channels->max_rx = vi->total_queue_pairs; > + channels->max_tx = vi->total_queue_pairs; > + channels->max_other = 0; > + channels->max_combined = 0; > + channels->rx_count = vi->num_queue_pairs; > + channels->tx_count = vi->num_queue_pairs; > + channels->other_count = 0; > + channels->combined_count = 0; > +} [...] It looks like the queue-pairs should be treated as 'combined channels', not separate RX and TX channels. Also you don't need to clear the other members; you can assume that the ethtool core will zero-initialise structures for 'get' operations. Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.
WARNING: multiple messages have this Message-ID (diff)
From: Ben Hutchings <bhutchings@solarflare.com> To: Jason Wang <jasowang@redhat.com> Cc: krkumar2@in.ibm.com, habanero@linux.vnet.ibm.com, mashirle@us.ibm.com, kvm@vger.kernel.org, mst@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, edumazet@google.com, tahm@linux.vnet.ibm.com, jwhan@filewood.snu.ac.kr, davem@davemloft.net, sri@us.ibm.com Subject: Re: [net-next RFC V5 5/5] virtio_net: support negotiating the number of queues through ctrl vq Date: Mon, 9 Jul 2012 21:13:23 +0100 [thread overview] Message-ID: <1341864803.2535.53.camel@bwh-desktop.uk.solarflarecom.com> (raw) In-Reply-To: <1341484194-8108-6-git-send-email-jasowang@redhat.com> On Thu, 2012-07-05 at 18:29 +0800, Jason Wang wrote: > This patch let the virtio_net driver can negotiate the number of queues it > wishes to use through control virtqueue and export an ethtool interface to let > use tweak it. > > As current multiqueue virtio-net implementation has optimizations on per-cpu > virtuqueues, so only two modes were support: > > - single queue pair mode > - multiple queue paris mode, the number of queues matches the number of vcpus > > The single queue mode were used by default currently due to regression of > multiqueue mode in some test (especially in stream test). > > Since virtio core does not support paritially deleting virtqueues, so during > mode switching the whole virtqueue were deleted and the driver would re-create > the virtqueues it would used. > > btw. The queue number negotiating were defered to .ndo_open(), this is because > only after feature negotitaion could we send the command to control virtqueue > (as it may also use event index). [...] > +static int virtnet_set_channels(struct net_device *dev, > + struct ethtool_channels *channels) > +{ > + struct virtnet_info *vi = netdev_priv(dev); > + u16 queues = channels->rx_count; > + unsigned status = VIRTIO_CONFIG_S_ACKNOWLEDGE | VIRTIO_CONFIG_S_DRIVER; > + > + if (channels->rx_count != channels->tx_count) > + return -EINVAL; [...] > +static void virtnet_get_channels(struct net_device *dev, > + struct ethtool_channels *channels) > +{ > + struct virtnet_info *vi = netdev_priv(dev); > + > + channels->max_rx = vi->total_queue_pairs; > + channels->max_tx = vi->total_queue_pairs; > + channels->max_other = 0; > + channels->max_combined = 0; > + channels->rx_count = vi->num_queue_pairs; > + channels->tx_count = vi->num_queue_pairs; > + channels->other_count = 0; > + channels->combined_count = 0; > +} [...] It looks like the queue-pairs should be treated as 'combined channels', not separate RX and TX channels. Also you don't need to clear the other members; you can assume that the ethtool core will zero-initialise structures for 'get' operations. Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.
next prev parent reply other threads:[~2012-07-09 20:13 UTC|newest] Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-07-05 10:29 [net-next RFC V5 0/5] Multiqueue virtio-net Jason Wang 2012-07-05 10:29 ` Jason Wang 2012-07-05 10:29 ` [net-next RFC V5 1/5] virtio_net: Introduce VIRTIO_NET_F_MULTIQUEUE Jason Wang 2012-07-05 10:29 ` Jason Wang 2012-07-05 10:29 ` [net-next RFC V5 2/5] virtio_ring: move queue_index to vring_virtqueue Jason Wang 2012-07-05 10:29 ` Jason Wang 2012-07-05 11:40 ` Sasha Levin 2012-07-05 11:40 ` Sasha Levin 2012-07-06 3:17 ` Jason Wang 2012-07-06 3:17 ` Jason Wang 2012-07-26 8:20 ` Paolo Bonzini 2012-07-26 8:20 ` Paolo Bonzini 2012-07-30 3:30 ` Jason Wang 2012-07-30 3:30 ` Jason Wang 2012-07-05 10:29 ` [net-next RFC V5 3/5] virtio: intorduce an API to set affinity for a virtqueue Jason Wang 2012-07-05 10:29 ` Jason Wang 2012-07-27 14:38 ` Paolo Bonzini 2012-07-27 14:38 ` Paolo Bonzini 2012-07-29 20:40 ` Michael S. Tsirkin 2012-07-29 20:40 ` Michael S. Tsirkin 2012-07-30 6:27 ` Paolo Bonzini 2012-08-09 15:14 ` Paolo Bonzini 2012-08-09 15:14 ` Paolo Bonzini 2012-08-09 15:13 ` Paolo Bonzini 2012-08-09 15:13 ` Paolo Bonzini 2012-08-09 15:35 ` Avi Kivity 2012-08-09 15:35 ` Avi Kivity 2012-07-05 10:29 ` [net-next RFC V5 4/5] virtio_net: multiqueue support Jason Wang 2012-07-05 10:29 ` Jason Wang 2012-07-05 20:02 ` Amos Kong 2012-07-05 20:02 ` Amos Kong 2012-07-06 7:45 ` Jason Wang 2012-07-06 7:45 ` Jason Wang 2012-07-20 13:40 ` Michael S. Tsirkin 2012-07-20 13:40 ` Michael S. Tsirkin 2012-07-21 12:02 ` Sasha Levin 2012-07-21 12:02 ` Sasha Levin 2012-07-23 5:54 ` Jason Wang 2012-07-23 5:54 ` Jason Wang 2012-07-23 9:28 ` Sasha Levin 2012-07-23 9:28 ` Sasha Levin 2012-07-30 3:29 ` Jason Wang 2012-07-30 3:29 ` Jason Wang 2012-07-29 9:44 ` Michael S. Tsirkin 2012-07-29 9:44 ` Michael S. Tsirkin 2012-07-30 3:26 ` Jason Wang 2012-07-30 3:26 ` Jason Wang 2012-07-30 13:00 ` Sasha Levin 2012-07-30 13:00 ` Sasha Levin 2012-07-23 5:48 ` Jason Wang 2012-07-23 5:48 ` Jason Wang 2012-07-29 9:50 ` Michael S. Tsirkin 2012-07-29 9:50 ` Michael S. Tsirkin 2012-07-30 5:15 ` Jason Wang 2012-07-30 5:15 ` Jason Wang 2012-07-05 10:29 ` [net-next RFC V5 5/5] virtio_net: support negotiating the number of queues through ctrl vq Jason Wang 2012-07-05 10:29 ` Jason Wang 2012-07-05 12:51 ` Sasha Levin 2012-07-05 12:51 ` Sasha Levin 2012-07-05 20:07 ` Amos Kong 2012-07-05 20:07 ` Amos Kong 2012-07-06 7:46 ` Jason Wang 2012-07-06 7:46 ` Jason Wang 2012-07-06 3:20 ` Jason Wang 2012-07-06 3:20 ` Jason Wang 2012-07-06 6:38 ` Stephen Hemminger 2012-07-06 6:38 ` Stephen Hemminger 2012-07-06 9:26 ` Jason Wang 2012-07-06 9:26 ` Jason Wang 2012-07-06 8:10 ` Sasha Levin 2012-07-06 8:10 ` Sasha Levin 2012-07-09 20:13 ` Ben Hutchings [this message] 2012-07-09 20:13 ` Ben Hutchings 2012-07-20 12:33 ` Michael S. Tsirkin 2012-07-20 12:33 ` Michael S. Tsirkin 2012-07-23 5:32 ` Jason Wang 2012-07-23 5:32 ` Jason Wang 2012-07-05 17:45 ` [net-next RFC V5 0/5] Multiqueue virtio-net Rick Jones 2012-07-05 17:45 ` Rick Jones 2012-07-06 7:42 ` Jason Wang 2012-07-06 7:42 ` Jason Wang 2012-07-06 16:23 ` Rick Jones 2012-07-06 16:23 ` Rick Jones 2012-07-09 3:23 ` Jason Wang 2012-07-09 3:23 ` Jason Wang 2012-07-09 16:46 ` Rick Jones 2012-07-09 16:46 ` Rick Jones 2012-07-08 8:19 ` Ronen Hod 2012-07-08 8:19 ` Ronen Hod 2012-07-09 5:35 ` Jason Wang 2012-07-09 5:35 ` Jason Wang
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