From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ravi Kerur Subject: [PATCH v1 1/3] virtio-net: Using single MSIX IRQ for TX/RX Q pair Date: Mon, 26 Oct 2015 10:52:47 -0700 Message-ID: <1445881969-24663-1-git-send-email-rkerur@gmail.com> Cc: jasowang@redhat.com, mst@redhat.com, rusty@rustcorp.com.au, Ravi Kerur To: netdev@vger.kernel.org Return-path: Received: from mail-pa0-f46.google.com ([209.85.220.46]:36710 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750790AbbJZRwi (ORCPT ); Mon, 26 Oct 2015 13:52:38 -0400 Received: by pacfv9 with SMTP id fv9so203438657pac.3 for ; Mon, 26 Oct 2015 10:52:37 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: Ported earlier patch from Jason Wang (dated 12/26/2014). This patch tries to reduce the number of MSIX irqs required for virtio-net by sharing a MSIX irq for each TX/RX queue pair through channels. If transport support channel, about half of the MSIX irqs were reduced. Signed-off-by: Ravi Kerur --- drivers/net/virtio_net.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index d8838ded..d705cce 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -72,6 +72,9 @@ struct send_queue { /* Name of the send queue: output.$index */ char name[40]; + + /* Name of the channel, shared with irq. */ + char channel_name[40]; }; /* Internal representation of a receive virtqueue */ @@ -1529,6 +1532,8 @@ static int virtnet_find_vqs(struct virtnet_info *vi) int ret = -ENOMEM; int i, total_vqs; const char **names; + const char **channel_names; + unsigned *channels; /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by * possible N-1 RX/TX queue pairs used in multiqueue mode, followed by @@ -1548,6 +1553,17 @@ static int virtnet_find_vqs(struct virtnet_info *vi) if (!names) goto err_names; + channel_names = kmalloc_array(vi->max_queue_pairs, + sizeof(*channel_names), + GFP_KERNEL); + if (!channel_names) + goto err_channel_names; + + channels = kmalloc_array(total_vqs, sizeof(*channels), + GFP_KERNEL); + if (!channels) + goto err_channels; + /* Parameters for control virtqueue, if any */ if (vi->has_cvq) { callbacks[total_vqs - 1] = NULL; @@ -1562,10 +1578,15 @@ static int virtnet_find_vqs(struct virtnet_info *vi) sprintf(vi->sq[i].name, "output.%d", i); names[rxq2vq(i)] = vi->rq[i].name; names[txq2vq(i)] = vi->sq[i].name; + sprintf(vi->sq[i].channel_name, "txrx.%d", i); + channel_names[i] = vi->sq[i].channel_name; + channels[rxq2vq(i)] = i; + channels[txq2vq(i)] = i; } ret = vi->vdev->config->find_vqs(vi->vdev, total_vqs, vqs, callbacks, - names); + names, channels, channel_names, + vi->max_queue_pairs); if (ret) goto err_find; @@ -1580,6 +1601,8 @@ static int virtnet_find_vqs(struct virtnet_info *vi) vi->sq[i].vq = vqs[txq2vq(i)]; } + kfree(channels); + kfree(channel_names); kfree(names); kfree(callbacks); kfree(vqs); @@ -1587,6 +1610,10 @@ static int virtnet_find_vqs(struct virtnet_info *vi) return 0; err_find: + kfree(channels); +err_channels: + kfree(channel_names); +err_channel_names: kfree(names); err_names: kfree(callbacks); -- 1.9.1