Re: [dpdk-dev] [PATCH] vhost: Fix retrieval of numa information in PMD

[Yuanhan Liu <yuanhan.liu@linux.intel.com>]

On Wed, Apr 06, 2016 at 02:05:51PM +0800, Tan, Jianfeng wrote:
> 
> 
> On 4/6/2016 1:44 PM, Yuanhan Liu wrote:
> >On Wed, Apr 06, 2016 at 01:32:12PM +0800, Tan, Jianfeng wrote:
> >>Hi,
> >>
> >>Just out of interest, seems that the message handling thread which runs
> >>new_device() is pthread_create() from the thread which calls the
> >>dev_start(), usually master thread, right? But it's not necessary to be the
> >>master thread to poll pkts from this vhost port, right? So what's the
> >>significance to record the numa_node information of message handling thread
> >>here? Shall we make the decision of numa_realloc based on the final PMD
> >>thread who is responsible for polling this vhost port?
> >It doesn't matter on which core we made the decision: the result
> >would be same since we are querying the numa node info of the
> >virtio_net dev struct.
> 
> OK, according to your hint, read numa_realloc() again, it's to keep *dev
> (struct virtio_net), *dev->virtqueue[], on the same numa socket of shared
> memory with virtio?

Sort of, and I'm guessing that the comment have already made it clear?

    /*
     * Reallocate virtio_dev and vhost_virtqueue data structure to make them on the
     * same numa node as the memory of vring descriptor.
     */

> 
> And numa_realloc() is called in vhost_set_vring_addr(), which is after
> new_device()?

It's actually before new_device().

	--yliu