Re: [dpdk-dev] [PATCH] vdpa/mlx5: use master core Id for vhost thread

[David Marchand <david.marchand@redhat.com>]

On Tue, Jul 28, 2020 at 9:20 AM Matan Azrad <matan@mellanox.com> wrote:
>
>
>
> From: David Marchand
> > On Tue, Jul 28, 2020 at 8:11 AM Xueming Li <xuemingl@mellanox.com>
> > wrote:
> > >
> > > With latest rte api, vdpa example failed on vq setup, the api to get
> > > event queue of specified core failed.
> > >
> > > The api to get event queue needs core id as input, but after commit
> > > 67ae5936c4fc36 ("eal: fix lcore accessors for non-EAL threads"), code
> > > of "vhost-event" thread to get current core returns -1, an invalid
> > > core id.
> > >
> > > As vhost thread created on same core of eal master core, this patch
> > > uses master core ID as a workaround.
> >
> > rte_lcore_to_cpu_id(-1) is supposed to return the current lcore id.
> > As explained in the commitlog of 67ae5936c4fc36, for a non-EAL thread
> > (which has no associated lcore by default) calling this function means
> > lcore_config[-1].core_id.
>
> Deosn't lcore mean core?

No.


> So, if the private thread run on a core that opened by EAL,
> Shouldn't the API return the lcore of the private thread core?

vhost-events is a control thread.
Was it working just by chance and returning 0 before?


-- 
David Marchand