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

[Tetsuya Mukawa <mukawa@igel.co.jp>]

On 2016/01/28 1:45, Xie, Huawei wrote:
> On 1/21/2016 7:09 PM, Tetsuya Mukawa wrote:
>> +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