[dpdk-dev] [PATCH v3 0/6] use IOVAs check based on DMA mask

[Alejandro Lucero]

On Mon, Oct 29, 2018 at 11:46 AM Thomas Monjalon <thomas at monjalon.net>
wrote:

> 29/10/2018 12:39, Alejandro Lucero:
> > I got a patch that solves a bug when calling rte_eal_dma_mask using the
> > mask instead of the maskbits. However, this does not solves the deadlock.
>
> The deadlock is a bigger concern I think.
>
>
I think once the call to rte_eal_check_dma_mask uses the maskbits instead
of the mask, calling rte_memseg_walk_thread_unsafe avoids the deadlock.

Yao, can you try with the attached patch?


> > Interestingly, the problem looks like a compiler one. Calling
> > rte_memseg_walk does not return when calling inside rt_eal_dma_mask, but
> if
> > you modify the call like this:
> >
> > -       if (rte_memseg_walk(check_iova, &mask))
> > +       if (!rte_memseg_walk(check_iova, &mask))
> >
> > it works, although the value returned to the invoker changes, of course.
> > But the point here is it should be the same behaviour when calling
> > rte_memseg_walk than before and it is not.
>
> Anyway, the coding style requires to save the return value in a variable,
> instead of nesting the call in an "if" condition.
> And the "if" check should be explicitly != 0 because it is not a real
> boolean.
>
> PS: please do not top post and avoid HTML emails, thanks
>
>
>