> -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Stephen Hemminger > Sent: Monday, October 19, 2015 11:44 PM > To: Amine Kherbouche > Cc: dev at dpdk.org > Subject: Re: [dpdk-dev] [dpdk-dev, PATCHv6 1/6] ethdev: enhance > rte_eth_(tx|rx)q_info struct > > On Tue, 20 Oct 2015 00:06:19 +0200 > Amine Kherbouche <amine.kherbouche at 6wind.com> wrote: > > > + uint16_t used_desc; /**< number of used descriptors */ > > + uint16_t free_desc; /**< number of free descriptors */ > > These two fields are obviously not SMP sfe.
I don't think they have to be. >From my thinking it is just a snapshot of SW state of the queue, that could be >used for statistics/watchdog/debugging purposes. > Also, they are redundant with the existing queue_count API? Yep, similar thought here: In the for Intel HW implementations: qinfo->used_desc = ixgbe_dev_rx_queue_count(dev, queue_id); It seems a bit redundant, as if user wants to know HW state it can call rte_eth_rx_queue_count() directly. >From other side: rte_eth_rx_queue_count() is quite heavyweight function, as >it scans HW descriptors to check their status. I think it should be better to return here just a snapshot of SW state: how many free/used RXDs are from PMD perspective (by collecting info from *_rx_queue structure, without reading actual HW registers/descriptors - as you done for TX queue info). Konstantin
