> -----邮件原件-----
> 发件人: Konstantin Ananyev <konstantin.anan...@huawei.com>
> 发送时间: Tuesday, February 28, 2023 3:32 AM
> 收件人: Feifei Wang <feifei.wa...@arm.com>; Konstantin Ananyev
> <konstantin.v.anan...@yandex.ru>; tho...@monjalon.net; Ferruh Yigit
> <ferruh.yi...@amd.com>; Andrew Rybchenko
> <andrew.rybche...@oktetlabs.ru>
> 抄送: dev@dpdk.org; nd <n...@arm.com>; Honnappa Nagarahalli
> <honnappa.nagaraha...@arm.com>; Ruifeng Wang
> <ruifeng.w...@arm.com>; nd <n...@arm.com>
> 主题: RE: [PATCH v3 1/3] ethdev: enable direct rearm with separate API
>
>
> Hi Feifei ,
>
>
> > > > + uint16_t *rearm_start;
> > > > + uint16_t *rearm_nb;
> > >
> > > I know that for Intel NICs uint16_t is sufficient, wonder would it
> > > always be for other vendors?
> > > Another thing to consider the case when ring position wrapping?
> > > Again I know that it is not required for Intel NICs, but would it be
> > > sufficient for API that supposed to be general?
> > >
> > For this, we re-define this structure:
> > rte_eth_rxq_rearm_data {
> > void *rx_sw_ring;
> > uint16_t *rearm_start;
> > uint16_t *rearm_nb;
> > }
> > ->
> > struct *rxq_recycle_info {
> > rte_mbuf **buf_ring;
> > uint16_t *offset = (uint16 *)(&rq->ci);
> > uint16_t *end;
> > uint16_t ring_size;
> >
> > }
> > For the new structure, *offset is a pointer for rearm-start index of
> > Rx buffer ring (consumer index). *end is a pointer for rearm-end index
> > Of Rx buffer ring (producer index).
> >
> > 1. we look up different pmds, some pmds using 'uint_16t' as index
> > size like intel PMD, some pmds using 'uint32_t' as index size like MLX5 or
> thunderx PMD.
> > For pmd using 'uint32_t', rearm starts at 'buf_ring[offset & (ring_size
> > -1)]',
> and 'uint16_t'
> > is enough for ring size.
>
> Sounds like a smart idea to me.
>
>
> >
> > 2. Good question. In general path, there is a constraint that
> > 'nb_rearm < ring_size - rq->ci', This can ensure no ring wrapping in
> > rearm. Thus in direct-rearm, we will refer to this to solve ring wrapping.
>
> Should work, I think...
> Just need not to forget to document it :)
Agree, we need to doc this.
