> -----Original Message-----
> From: Yigit, Ferruh
> Sent: Tuesday, September 10, 2019 23:36
> To: Wang, Haiyue <haiyue.w...@intel.com>; Richardson, Bruce
> <bruce.richard...@intel.com>
> Cc: 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 9/10/2019 4:18 PM, Wang, Haiyue wrote:
> >> -----Original Message-----
> >> From: Yigit, Ferruh
> >> Sent: Tuesday, September 10, 2019 23:03
> >> To: Wang, Haiyue <haiyue.w...@intel.com>; Richardson, Bruce
> >> <bruce.richard...@intel.com>
> >> Cc: 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 9/10/2019 3:19 PM, Wang, Haiyue wrote:
> >>>> -----Original Message-----
> >>>> From: Yigit, Ferruh
> >>>> Sent: Tuesday, September 10, 2019 17:15
> >>>> To: Wang, Haiyue <haiyue.w...@intel.com>; Richardson, Bruce
> >>>> <bruce.richard...@intel.com>
> >>>> Cc: 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 9/10/2019 9:37 AM, Wang, Haiyue wrote:
> >>>>>> -----Original Message-----
> >>>>>> From: Yigit, Ferruh
> >>>>>> Sent: Tuesday, September 10, 2019 16:07
> >>>>>> To: Wang, Haiyue <haiyue.w...@intel.com>; Richardson, Bruce
> >>>>>> <bruce.richard...@intel.com>
> >>>>>> Cc: 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 9/10/2019 5:36 AM, Wang, Haiyue wrote:
> >>>>>>> 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.
> >>>>>>>>>>
> >>>>>>>>>
> >>>>>>>
> >>>>>>> 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),
> >>>>>>
> >>>>>> Do we need to have bitfields for this, I was suggesting reserve 4
> >>>>>> bits, bit 2-5
> >>>>>> (inclusive) and use their value:
> >>>>>>
> >>>>>> BURST_VECTOR_MODE_IDX = 2
> >>>>>> BURST_VECTOR_MODE_SIZE = 4
> >>>>>> BURST_VECTOR_MODE_MASK =
> >>>>>> ((1 << BURST_VECTOR_MODE_SIZE) - 1) << BURST_VECTOR_MODE_IDX
> >>>>>>
> >>>>>> vector_mode = (options & BURST_VECTOR_MODE_MASK) >>
> >>>>>> BURST_VECTOR_MODE_IDX
> >>>>>>
> >>>>>> if (vector_mode == 0) // BURST_SSE
> >>>>>> if (vector_mode == 1) // BURST_AVX2
> >>>>>> if (vector_mode == 2) // BURST_AVX512
> >>>>>> if (vector_mode == 3) // BURST_NEON
> >>>>> }
> >>>>>
> >>>>
> >>>> I can see how you intended use it, only they don't need to be bitfield
> >>>> and using
> >>>> with value saves bits.
> >>>> Also I think good to reserve some bits for future modes.
> >>>>
> >>>
> >>> I think I understand your 'value saves bits' concern now:
> >>>
> >>> What you mentioned value such as 1, 2, 3 has been *shifted* as new
> >>> options: (1 << 2),
> >>> (2 << 2), (3 << 2). The *shifted* value seems be easily for using, like,
> >>> you don't
> >>> need to re-define another enum like enum ...vector_mode { SSE, AVX2 } for
> >>> accessing.
> >>> And we can extract the vector mode easy: options &
> >>> BURST_VECTOR_MODE_MASK, no need to
> >>> shift right again for getting the pure number. And for displaying name,
> >>> it also should
> >>> be consistent:
> >>> ...
> >>> case RTE_ETH_BURST_VECTOR: return "Vector";
> >>> case RTE_ETH_BURST_ALTIVEC: return "AltiVec";
> >>> case RTE_ETH_BURST_NEON: return "Neon";
> >>>
> >>
> >> Yep, this is what I was suggesting, agree that bitwise is a little easier,
> >> and
> >> specially after having separate Rx/Tx APIs there are enough room in the
> >> variable, so ok with your suggestion.
> >> But please reserve some additional room future vectorisation modes, I
> >> would say
> >> overall 14 would be good, so first word can be for modes.
> >
> > Got it, will change 4 bits for vector mode for saving the bit space.
> >
>
> Please keep as you suggested, as bitfiled for simplicity, it looks like there
> is
> already enough space.
OK, remove the 'BURST_NORMAL' free one more bit.
