Re: [RFC] [ver3 PATCH 3/6] virtio_net: virtio_net driver changes
From: Ben Hutchings <hidden>
Date: 2011-11-18 01:08:08
Also in:
kvm
On Fri, 2011-11-11 at 18:34 +0530, Krishna Kumar wrote:
Changes for multiqueue virtio_net driver.
[...]
quoted hunk ↗ jump to hunk
@@ -677,25 +730,35 @@ static struct rtnl_link_stats64 *virtnet { struct virtnet_info *vi = netdev_priv(dev); int cpu; - unsigned int start; for_each_possible_cpu(cpu) { - struct virtnet_stats __percpu *stats - = per_cpu_ptr(vi->stats, cpu); - u64 tpackets, tbytes, rpackets, rbytes; - - do { - start = u64_stats_fetch_begin(&stats->syncp); - tpackets = stats->tx_packets; - tbytes = stats->tx_bytes; - rpackets = stats->rx_packets; - rbytes = stats->rx_bytes; - } while (u64_stats_fetch_retry(&stats->syncp, start)); - - tot->rx_packets += rpackets; - tot->tx_packets += tpackets; - tot->rx_bytes += rbytes; - tot->tx_bytes += tbytes; + int qpair; + + for (qpair = 0; qpair < vi->num_queue_pairs; qpair++) { + struct virtnet_send_stats __percpu *tx_stat; + struct virtnet_recv_stats __percpu *rx_stat;
While you're at it, you can drop the per-CPU stats and make them only per-queue. There is unlikely to be any benefit in maintaining them per-CPU while receive and transmit processing is serialised per-queue. [...]
+static int invoke_find_vqs(struct virtnet_info *vi)
+{
+ vq_callback_t **callbacks;
+ struct virtqueue **vqs;
+ int ret = -ENOMEM;
+ int i, total_vqs;
+ char **names;
+
+ /*
+ * We expect 1 RX virtqueue followed by 1 TX virtqueue, followed
+ * by the same 'vi->num_queue_pairs-1' more times, and optionally
+ * one control virtqueue.
+ */
+ total_vqs = vi->num_queue_pairs * 2 +
+ virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ);
+
+ /* Allocate space for find_vqs parameters */
+ vqs = kmalloc(total_vqs * sizeof(*vqs), GFP_KERNEL);
+ callbacks = kmalloc(total_vqs * sizeof(*callbacks), GFP_KERNEL);
+ names = kmalloc(total_vqs * sizeof(*names), GFP_KERNEL);
+ if (!vqs || !callbacks || !names)
+ goto err;
+
+ /* Allocate/initialize parameters for recv virtqueues */
+ for (i = 0; i < vi->num_queue_pairs * 2; i += 2) {
+ callbacks[i] = skb_recv_done;
+ names[i] = kasprintf(GFP_KERNEL, "input.%d", i / 2);
+ if (!names[i])
+ goto err;
+ }
+
+ /* Allocate/initialize parameters for send virtqueues */
+ for (i = 1; i < vi->num_queue_pairs * 2; i += 2) {
+ callbacks[i] = skb_xmit_done;
+ names[i] = kasprintf(GFP_KERNEL, "output.%d", i / 2);
+ if (!names[i])
+ goto err;
+ }[...] The RX and TX interrupt names for a multiqueue device should follow the formats "<device>-rx-<index>" and "<device>-tx-<index>". 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.