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[Qemu-devel] [PATCH V7 14/16] virtio-pci: speedup MSI-X masking and unma
From: |
Jason Wang |
Subject: |
[Qemu-devel] [PATCH V7 14/16] virtio-pci: speedup MSI-X masking and unmasking |
Date: |
Thu, 23 Apr 2015 14:21:47 +0800 |
This patch tries to speed up the MSI-X masking and unmasking through
the mapping between vector and queues. With this patch it will there's
no need to go through all possible virtqueues, which may help to
reduce the time spent when doing MSI-X masking/unmasking a single
vector when more than hundreds or even thousands of virtqueues were
supported.
Tested with 80 queue pairs virito-net-pci by changing the smp affinity
in the background and doing netperf in the same time:
Before the patch:
5711.70 Gbits/sec
After the patch:
6830.98 Gbits/sec
About 19.6% improvements in throughput.
Cc: Michael S. Tsirkin <address@hidden>
Signed-off-by: Jason Wang <address@hidden>
---
hw/virtio/virtio-pci.c | 40 +++++++++++++++++++++-------------------
1 file changed, 21 insertions(+), 19 deletions(-)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index c38f33f..7d01500 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -632,28 +632,30 @@ static int virtio_pci_vector_unmask(PCIDevice *dev,
unsigned vector,
{
VirtIOPCIProxy *proxy = container_of(dev, VirtIOPCIProxy, pci_dev);
VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
- int ret, queue_no;
+ VirtQueue *vq = virtio_vector_first_queue(vdev, vector);
+ int ret, index, unmasked = 0;
- for (queue_no = 0; queue_no < proxy->nvqs_with_notifiers; queue_no++) {
- if (!virtio_queue_get_num(vdev, queue_no)) {
+ while (vq) {
+ index = virtio_get_queue_index(vq);
+ if (!virtio_queue_get_num(vdev, index)) {
break;
}
- if (virtio_queue_vector(vdev, queue_no) != vector) {
- continue;
- }
- ret = virtio_pci_vq_vector_unmask(proxy, queue_no, vector, msg);
+ ret = virtio_pci_vq_vector_unmask(proxy, index, vector, msg);
if (ret < 0) {
goto undo;
}
+ vq = virtio_vector_next_queue(vq);
+ ++unmasked;
}
+
return 0;
undo:
- while (--queue_no >= 0) {
- if (virtio_queue_vector(vdev, queue_no) != vector) {
- continue;
- }
- virtio_pci_vq_vector_mask(proxy, queue_no, vector);
+ vq = virtio_vector_first_queue(vdev, vector);
+ while (vq && --unmasked >= 0) {
+ index = virtio_get_queue_index(vq);
+ virtio_pci_vq_vector_mask(proxy, index, vector);
+ vq = virtio_vector_next_queue(vq);
}
return ret;
}
@@ -662,16 +664,16 @@ static void virtio_pci_vector_mask(PCIDevice *dev,
unsigned vector)
{
VirtIOPCIProxy *proxy = container_of(dev, VirtIOPCIProxy, pci_dev);
VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
- int queue_no;
+ VirtQueue *vq = virtio_vector_first_queue(vdev, vector);
+ int index;
- for (queue_no = 0; queue_no < proxy->nvqs_with_notifiers; queue_no++) {
- if (!virtio_queue_get_num(vdev, queue_no)) {
+ while (vq) {
+ index = virtio_get_queue_index(vq);
+ if (!virtio_queue_get_num(vdev, index)) {
break;
}
- if (virtio_queue_vector(vdev, queue_no) != vector) {
- continue;
- }
- virtio_pci_vq_vector_mask(proxy, queue_no, vector);
+ virtio_pci_vq_vector_mask(proxy, index, vector);
+ vq = virtio_vector_next_queue(vq);
}
}
--
2.1.0
- Re: [Qemu-devel] [PATCH V7 08/16] virtio: introduce bus specific queue limit, (continued)
[Qemu-devel] [PATCH V7 09/16] virtio-ccw: introduce ccw specific queue limit, Jason Wang, 2015/04/23
[Qemu-devel] [PATCH V7 11/16] virtio-mmio: switch to bus specific queue limit, Jason Wang, 2015/04/23
[Qemu-devel] [PATCH V7 10/16] virtio-s390: switch to bus specific queue limit, Jason Wang, 2015/04/23
[Qemu-devel] [PATCH V7 12/16] virtio-pci: switch to use bus specific queue limit, Jason Wang, 2015/04/23
[Qemu-devel] [PATCH V7 13/16] virtio: introduce vector to virtqueues mapping, Jason Wang, 2015/04/23
[Qemu-devel] [PATCH V7 14/16] virtio-pci: speedup MSI-X masking and unmasking,
Jason Wang <=
[Qemu-devel] [PATCH V7 15/16] virtio-pci: increase the maximum number of virtqueues to 513, Jason Wang, 2015/04/23
[Qemu-devel] [PATCH V7 16/16] pci: remove hard-coded bar size in msix_init_exclusive_bar(), Jason Wang, 2015/04/23
Re: [Qemu-devel] [PATCH V7 00/16] Support more virtio queues, Cornelia Huck, 2015/04/23
Re: [Qemu-devel] [PATCH V7 00/16] Support more virtio queues, Michael S. Tsirkin, 2015/04/27