Re: [RFC PATCH 5/5] virtio: Extend virtio-net PMD to support container environment

On 2016/01/28 1:45, Xie, Huawei wrote:

On 1/21/2016 7:09 PM, Tetsuya Mukawa wrote:

quoted

+qtest_find_pci_device(struct qtest_session *s, uint16_t bus, uint8_t device)
+{
+	struct qtest_pci_device *dev;
+	uint32_t val;
+
+	val = qtest_pci_inl(s, bus, device, 0, 0);
+	TAILQ_FOREACH(dev, &s->head, next) {
+		if (val == ((uint32_t)dev->device_id << 16 | dev->vendor_id)) {
+			dev->bus_addr = bus;
+			dev->device_addr = device;
+			return;
+		}
+
+	}
+}
+
+static int
+qtest_init_pci_devices(struct qtest_session *s)
+{
+	struct qtest_pci_device *dev;
+	uint16_t bus;
+	uint8_t device;
+	int ret;
+
+	/* Find devices */
+	bus = 0;
+	do {
+		device = 0;
+		do {
+			qtest_find_pci_device(s, bus, device);
+		} while (device++ != NB_DEVICE - 1);
+	} while (bus++ != NB_BUS - 1);

Seems this scan of all the pci devices is very time consuming operation,
and each scan involves socket communication.
Do you measure how long it takes to do the pci devices initialization?

I measured it, and seems it takes 0.35 seconds in my environment.
This will be done only once when the port is initialized. Probably it's
not so heady.

Tetsuya