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[Qemu-devel] [PULL 13/28] virtio-pci: speedup MSI-X masking and unmaskin
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] [PULL 13/28] virtio-pci: speedup MSI-X masking and unmasking |
Date: |
Mon, 11 May 2015 14:47:52 +0200 |
From: Jason Wang <address@hidden>
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>
Reviewed-by: Michael S. Tsirkin <address@hidden>
Signed-off-by: Michael S. Tsirkin <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 6ae24a0..5ea4656 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -630,28 +630,30 @@ 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;
}
@@ -660,16 +662,16 @@ 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);
}
}
--
MST
- [Qemu-devel] [PULL 03/28] hw/i386/acpi-build: move generic acpi building helpers into dedictated file, (continued)
- [Qemu-devel] [PULL 03/28] hw/i386/acpi-build: move generic acpi building helpers into dedictated file, Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 02/28] hw/i386: Move ACPI header definitions in an arch-independent location, Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 05/28] virtio-net: fix the upper bound when trying to delete queues, Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 06/28] pc: add 2.4 machine types, Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 07/28] spapr: add machine type specific instance init function, Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 08/28] ppc: spapr: add 2.4 machine type, Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 09/28] monitor: replace the magic number 255 with MAX_QUEUE_NUM, Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 10/28] monitor: check return value of qemu_find_net_clients_except(), Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 11/28] virtio-ccw: using VIRTIO_NO_VECTOR instead of 0 for invalid virtqueue, Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 12/28] virtio: introduce vector to virtqueues mapping, Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 13/28] virtio-pci: speedup MSI-X masking and unmasking,
Michael S. Tsirkin <=
- [Qemu-devel] [PULL 14/28] pci: remove hard-coded bar size in msix_init_exclusive_bar(), Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 16/28] docs: update documentation for memory hot unplug, Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 17/28] acpi, mem-hotplug: add acpi_memory_slot_status() to get MemStatus, Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 15/28] virtio: coding style tweak, Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 18/28] acpi, mem-hotplug: add unplug request cb for memory device, Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 19/28] acpi, mem-hotplug: add unplug cb for memory device, Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 21/28] acpi: fix "Memory device control fields" register, Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 20/28] acpi: extend aml_field() to support UpdateRule, Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 24/28] acpi: add a missing backslash to the \_SB scope., Michael S. Tsirkin, 2015/05/11
- [Qemu-devel] [PULL 25/28] pci: Merge pci_nic_init() into pci_nic_init_nofail(), Michael S. Tsirkin, 2015/05/11