Thanks Ferruh, Bruce.
> -----Original Message-----
> From: Yigit, Ferruh
> Sent: Monday, September 9, 2019 21:18
> To: Richardson, Bruce <bruce.richard...@intel.com>
> Cc: Wang, Haiyue <haiyue.w...@intel.com>; Ray Kinsella <m...@ashroe.eu>;
> dev@dpdk.org; Sun, Chenmin
> <chenmin....@intel.com>
> Subject: Re: [dpdk-dev] [RFC v2 1/3] ethdev: add the API for getting trace
> information
>
> On 9/9/2019 1:50 PM, Ferruh Yigit wrote:
> > On 9/9/2019 1:40 PM, Bruce Richardson wrote:
> >> On Mon, Sep 09, 2019 at 12:23:36PM +0100, Ferruh Yigit wrote:
> >>> On 9/7/2019 3:42 AM, Wang, Haiyue wrote:
> >>>>> -----Original Message-----
> >>>>> From: Yigit, Ferruh
> >>>>> Sent: Friday, September 6, 2019 22:22
> >>>>> To: Ray Kinsella <m...@ashroe.eu>; Wang, Haiyue <haiyue.w...@intel.com>
> >>>>> Cc: dev@dpdk.org
> >>>>> Subject: Re: [dpdk-dev] [RFC v2 1/3] ethdev: add the API for getting
> >>>>> trace information
> >>>>>
> >>>>> On 8/13/2019 1:51 PM, Ray Kinsella wrote:
> >>>>>>
> >>>>>>
> >>>>>> On 13/08/2019 04:24, Stephen Hemminger wrote:
> >>>>>>> On Tue, 13 Aug 2019 11:06:10 +0800
> >>>>>>> Haiyue Wang <haiyue.w...@intel.com> wrote:
> >>>>>>>
> >>>>>>>> Enhance the PMD to support retrieving trace information like
> >>>>>>>> Rx/Tx burst selection etc.
> >>>>>>>>
> >>>>>>>> Signed-off-by: Haiyue Wang <haiyue.w...@intel.com>
> >>>>>>>> ---
> >>>>>>>> lib/librte_ethdev/rte_ethdev.c | 18 ++++++++++++++++++
> >>>>>>>> lib/librte_ethdev/rte_ethdev.h | 9 +++++++++
> >>>>>>>> lib/librte_ethdev/rte_ethdev_core.h | 4 ++++
> >>>>>>>> 3 files changed, 31 insertions(+)
> >>>>>>>>
> >>>>>>>> diff --git a/lib/librte_ethdev/rte_ethdev.c
> >>>>>>>> b/lib/librte_ethdev/rte_ethdev.c
> >>>>>>>> index 17d183e..6098fad 100644
> >>>>>>>> --- a/lib/librte_ethdev/rte_ethdev.c
> >>>>>>>> +++ b/lib/librte_ethdev/rte_ethdev.c
> >>>>>>>> @@ -4083,6 +4083,24 @@ rte_eth_tx_queue_info_get(uint16_t port_id,
> >>>>>>>> uint16_t queue_id,
> >>>>>>>> }
> >>>>>>>>
> >>>>>>>> int
> >>>>>>>> +rte_eth_trace_info_get(uint16_t port_id, uint16_t queue_id,
> >>>>>>>> + enum rte_eth_trace type, char *buf, int sz)
> >>>>>
> >>>>> Better to use struct as argument instead of individual variables
> >>>>> because it is
> >>>>> easier to extend the struct later if needed.
> >>>>>
> >>>>>>>> +{
> >>>>>>>> + struct rte_eth_dev *dev;
> >>>>>>>> +
> >>>>>>>> + RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
> >>>>>>>> +
> >>>>>>>> + if (buf == NULL)
> >>>>>>>> + return -EINVAL;
> >>>>>>>> +
> >>>>>>>> + dev = &rte_eth_devices[port_id];
> >>>>>>>> +
> >>>>>>>> + RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->trace_info_get,
> >>>>>>>> -ENOTSUP);
> >>>>>>>> +
> >>>>>>>> + return dev->dev_ops->trace_info_get(dev, queue_id, type, buf,
> >>>>>>>> sz);
> >>>>>>>
> >>>>>>> What if queueid is out of bounds?
> >>>>>>>
> >>>>>>> The bigger problem is that this information is like a log message
> >>>>>>> and unstructured, which makes it device specific and useless for
> >>>>>>> automation.
> >>>>>>
> >>>>>> IMHO - this is much better implemented as a capability bitfield, that
> >>>>>> can be queried.
> >>>>>
> >>>>> +1 to return the datapath capability as bitfield.
> >>>>>
> >>>>> Also +1 to have a new API,
> >>>>> - I am not sure about the API name, 'rte_eth_trace_info_get()', can we
> >>>>> find
> >>>>> something better instead of 'trace' there.
> >>>>> - I think we should limit this API only to get current datapath
> >>>>> configuration,
> >>>>> for clarity of the API don't return capability or not datapath related
> >>>>> config.
> >>>>>
> >>>>> Also this information not always supported in queue level, what do you
> >>>>> think
> >>>>> having ability to get this information in port level,
> >>>>> like this API can return a struct, which may have a field that says if
> >>>>> the
> >>>>> output is for queue or port, or this can be another bitfield, what do
> >>>>> you think?
> >>>>>
> >>>>
> >>>> #define RX_SCALAR (1ULL < 0)
> >>>> #define RX_VECTOR_AVX2 ...
> >>>
> >>> What about having RX_VECTOR value, later another bit group for the
> >>> details of
> >>> the vectorization:
> >>> SSE
> >>> AVX2
> >>> AVX512
> >>> NEON
> >>> ALTIVEC
> >>>
> >>> Since above options can exist together, what about using values for them
> >>> instead
> >>> of bitfields? Reserving 4 bits, 2^4 = 16, can be enough I think for long
> >>> term.
> >>>
> >> Rather than having named vector types, we just need to worry about the ones
> >> for the current architecture. Therefore I'd suggest just using vector
> >> widths, one bit each for 16B, 32B and 64B vector support. For supporting
> >> multiple values, 16 combinations is not enough for all the possibilities.
> >>
> >
> > vector width can be an option too, no objection there. But this is only for
> > current configuration, so it can be a combination, we have now 5 types and
> > allocating space for 16.
> >
>
> correction: it can *not* be a combination
I think we can merge the RX_VECTOR and TX_VECTOR together, use 6 bits for vector
mode detail. And for vector width, the SSE, NEON name should indicates it ?
I renamed the definitions to try to make things clear.
enum rte_eth_burst_mode_option {
BURST_SCALAR = (1 << 0),
BURST_VECTOR = (1 << 1),
BURST_VECTOR_MODE_MASK = (0x3F << 2),
BURST_ALTIVEC = (1 << 2),
BURST_NEON = (2 << 2),
BURST_SSE = (3 << 2),
BURST_AVX2 = (4 << 2),
BURST_AVX512 = (5 << 2),
BURST_SCATTERED = (1 << 8),
BURST_BULK_ALLOC = (1 << 9),
BURST_NORMAL = (1 << 10),
BURST_SIMPLE = (1 << 11),
};
/**
* Ethernet device RX/TX queue packet burst mode information structure.
* Used to retrieve information about packet burst mode setting.
*/
struct rte_eth_burst_mode {
uint32_t per_queue_support:1; /**< Support to set per queue burst */
uint64_t options;
};
And three APIs:
1.
__rte_experimental
int rte_eth_rx_burst_mode_get(uint16_t port_id, uint16_t queue_id,
struct rte_eth_burst_mode *mode);
2.
__rte_experimental
int rte_eth_tx_burst_mode_get(uint16_t port_id, uint16_t queue_id,
struct rte_eth_burst_mode *mode);
3.
__rte_experimental
const char *
rte_eth_burst_mode_option_name(uint64_t option);
PMD two ops:
typedef void (*eth_burst_mode_get_t)(struct rte_eth_dev *dev,
uint16_t queue_id, struct rte_eth_burst_mode *mode);
struct eth_dev_ops {
...
eth_burst_mode_get_t rx_burst_mode_get; /**< Get RX burst mode */
eth_burst_mode_get_t tx_burst_mode_get; /**< Get TX burst mode */
...
};
