Re: [dpdk-dev] [PATCH] ethdev: add queue state when retrieve queue information

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> 
> 
> 在 2021/3/22 23:45, Ananyev, Konstantin 写道:
> >
> >
> >> -----Original Message-----
> >> From: dev <dev-bounces@dpdk.org> On Behalf Of Andrew Rybchenko
> >> Sent: Monday, March 22, 2021 2:49 PM
> >> To: Yigit, Ferruh <ferruh.yigit@intel.com>; Lijun Ou <oulijun@huawei.com>; thomas@monjalon.net
> >> Cc: dev@dpdk.org; linuxarm@openeuler.org; Andrew Rybchenko <arybchenko@solarflare.com>; David Marchand
> >> <david.marchand@redhat.com>; Ray Kinsella <mdr@ashroe.eu>; Luca Boccassi <bluca@debian.org>
> >> Subject: Re: [dpdk-dev] [PATCH] ethdev: add queue state when retrieve queue information
> >>
> >> On 3/22/21 12:22 PM, Ferruh Yigit wrote:
> >>> On 3/18/2021 12:25 PM, Lijun Ou wrote:
> >>>> Currently, upper-layer application could get queue state only
> >>>> through pointers such as dev->data->tx_queue_state[queue_id],
> >>>> this is not the recommended way to access it. So this patch
> >>>> add get queue state when call rte_eth_rx_queue_info_get and
> >>>> rte_eth_tx_queue_info_get API.
> >>>>
> >>>> Note: The hairpin queue is not supported with above
> >>>> rte_eth_*x_queue_info_get, so the queue state could be
> >>>> RTE_ETH_QUEUE_STATE_STARTED or RTE_ETH_QUEUE_STATE_STOPPED.
> >>>> Note: After add queue_state field, the 'struct rte_eth_rxq_info' size
> >>>> remains 128B, and the 'struct rte_eth_txq_info' size remains 64B, so
> >>>> it could be ABI compatible.
> >>>>
> >>>> Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
> >>>> Signed-off-by: Lijun Ou <oulijun@huawei.com>
> >>>
> >>> <...>
> >>>
> >>>> diff --git a/lib/librte_ethdev/rte_ethdev.h
> >>>> b/lib/librte_ethdev/rte_ethdev.h
> >>>> index efda313..3b83c5a 100644
> >>>> --- a/lib/librte_ethdev/rte_ethdev.h
> >>>> +++ b/lib/librte_ethdev/rte_ethdev.h
> >>>> @@ -1591,6 +1591,8 @@ struct rte_eth_rxq_info {
> >>>>        uint8_t scattered_rx;       /**< scattered packets RX supported. */
> >>>>        uint16_t nb_desc;           /**< configured number of RXDs. */
> >>>>        uint16_t rx_buf_size;       /**< hardware receive buffer size. */
> >>>> +    /**< Queues state: STARTED(1) / STOPPED(0). */
> >>>> +    uint8_t queue_state;
> >>>>    } __rte_cache_min_aligned;
> >>>>      /**
> >>>> @@ -1600,6 +1602,8 @@ struct rte_eth_rxq_info {
> >>>>    struct rte_eth_txq_info {
> >>>>        struct rte_eth_txconf conf; /**< queue config parameters. */
> >>>>        uint16_t nb_desc;           /**< configured number of TXDs. */
> >>>> +    /**< Queues state: STARTED(1) / STOPPED(0). */
> >>>> +    uint8_t queue_state;
> >>>>    } __rte_cache_min_aligned;
> >>>>      /* Generic Burst mode flag definition, values can be ORed. */
> >>>>
> >>>
> >>> This is causing an ABI warning [1], but I guess it is safe since the
> >>> size of the struct is not changing (cache align). Adding a few more
> >>> people to comment.
> >>>
> >>>
> >>> [1]
> >>> https://travis-ci.com/github/ovsrobot/dpdk/builds/220497651
> >>
> >> Frankly speaking I dislike addition of queue_state as uint8_t.
> >> IMHO it should be either 'bool started' or enum to support more
> >> states in the future if we need.
> >
> > I think we already have set of defines for it:
> > lib/librte_ethdev/rte_ethdev_driver.h:925:#define RTE_ETH_QUEUE_STATE_STOPPED 0
> > lib/librte_ethdev/rte_ethdev_driver.h:926:#define RTE_ETH_QUEUE_STATE_STARTED 1
> > lib/librte_ethdev/rte_ethdev_driver.h:927:#define RTE_ETH_QUEUE_STATE_HAIRPIN 2
> At the latest date, the rte_ethdev_driver.h file does not exist.

Yep, It was renamed to ethdev_driver.h.
But the defines are still there.

> >
> > If we want to publish it, then might be enough just move these macros to rte_ethdev.h or so.
> >
> > About uint8_t vs enum - yes, in principle enum would be a bit nicer,
> > but right now rte_eth_dev_data.(rx|tx)_queue_state[]  itself is an array of uint8_t.
> > So probably not much point to waste extra 3B in rte_eth_(rxq|txq)_info.
> > Unless in future will want to change it in struct rte_eth_dev_data too
> > (or even hide it inside dev private queue data).
> >
> >
> >