From: Pavan Nikhilesh Bhagavatula <pbhagavatula@marvell.com> To: "McDaniel, Timothy" <timothy.mcdaniel@intel.com>, Jerin Jacob <jerinjacobk@gmail.com> Cc: Ray Kinsella <mdr@ashroe.eu>, Neil Horman <nhorman@tuxdriver.com>, "Jerin Jacob Kollanukkaran" <jerinj@marvell.com>, Mattias Rönnblom <mattias.ronnblom@ericsson.com>, dpdk-dev <dev@dpdk.org>, "Eads, Gage" <gage.eads@intel.com>, "Van Haaren, Harry" <harry.van.haaren@intel.com> Subject: Re: [dpdk-dev] [PATCH 01/27] eventdev: dlb upstream prerequisites Date: Tue, 30 Jun 2020 20:40:18 +0000 Message-ID: <BN6PR18MB1140CE7C396DC68F562B5E87DE6F0@BN6PR18MB1140.namprd18.prod.outlook.com> (raw) In-Reply-To: <SN6PR11MB31032CD6AEEF141FEEFCF8709E6F0@SN6PR11MB3103.namprd11.prod.outlook.com> >-----Original Message----- >From: dev <dev-bounces@dpdk.org> On Behalf Of McDaniel, Timothy >Sent: Wednesday, July 1, 2020 12:57 AM >To: Jerin Jacob <jerinjacobk@gmail.com> >Cc: Ray Kinsella <mdr@ashroe.eu>; Neil Horman ><nhorman@tuxdriver.com>; Jerin Jacob Kollanukkaran ><jerinj@marvell.com>; Mattias Rönnblom ><mattias.ronnblom@ericsson.com>; dpdk-dev <dev@dpdk.org>; Eads, >Gage <gage.eads@intel.com>; Van Haaren, Harry ><harry.van.haaren@intel.com> >Subject: Re: [dpdk-dev] [PATCH 01/27] eventdev: dlb upstream >prerequisites > >>-----Original Message----- >>From: Jerin Jacob <jerinjacobk@gmail.com> >>Sent: Tuesday, June 30, 2020 10:58 AM >>To: McDaniel, Timothy <timothy.mcdaniel@intel.com> >>Cc: Ray Kinsella <mdr@ashroe.eu>; Neil Horman ><nhorman@tuxdriver.com>; >>Jerin Jacob <jerinj@marvell.com>; Mattias Rönnblom >><mattias.ronnblom@ericsson.com>; dpdk-dev <dev@dpdk.org>; Eads, >Gage >><gage.eads@intel.com>; Van Haaren, Harry ><harry.van.haaren@intel.com> >>Subject: Re: [dpdk-dev] [PATCH 01/27] eventdev: dlb upstream >prerequisites >> >>On Tue, Jun 30, 2020 at 9:12 PM McDaniel, Timothy >><timothy.mcdaniel@intel.com> wrote: >>> >>> >-----Original Message----- >>> >From: Jerin Jacob <jerinjacobk@gmail.com> >>> >Sent: Monday, June 29, 2020 11:21 PM >>> >To: McDaniel, Timothy <timothy.mcdaniel@intel.com> >>> >Cc: Ray Kinsella <mdr@ashroe.eu>; Neil Horman ><nhorman@tuxdriver.com>; >>> >Jerin Jacob <jerinj@marvell.com>; Mattias Rönnblom >>> ><mattias.ronnblom@ericsson.com>; dpdk-dev <dev@dpdk.org>; >Eads, Gage >>> ><gage.eads@intel.com>; Van Haaren, Harry ><harry.van.haaren@intel.com> >>> >Subject: Re: [dpdk-dev] [PATCH 01/27] eventdev: dlb upstream >prerequisites >>> > >>> >On Tue, Jun 30, 2020 at 1:01 AM McDaniel, Timothy >>> ><timothy.mcdaniel@intel.com> wrote: >>> >> >>> >> -----Original Message----- >>> >> From: Jerin Jacob <jerinjacobk@gmail.com> >>> >> Sent: Saturday, June 27, 2020 2:45 AM >>> >> To: McDaniel, Timothy <timothy.mcdaniel@intel.com>; Ray >Kinsella >>> ><mdr@ashroe.eu>; Neil Horman <nhorman@tuxdriver.com> >>> >> Cc: Jerin Jacob <jerinj@marvell.com>; Mattias Rönnblom >>> ><mattias.ronnblom@ericsson.com>; dpdk-dev <dev@dpdk.org>; >Eads, Gage >>> ><gage.eads@intel.com>; Van Haaren, Harry ><harry.van.haaren@intel.com> >>> >> Subject: Re: [dpdk-dev] [PATCH 01/27] eventdev: dlb upstream >prerequisites >>> >> >>> >> > + >>> >> > +/** Event port configuration structure */ >>> >> > +struct rte_event_port_conf_v20 { >>> >> > + int32_t new_event_threshold; >>> >> > + /**< A backpressure threshold for new event enqueues on >this port. >>> >> > + * Use for *closed system* event dev where event capacity >is limited, >>> >> > + * and cannot exceed the capacity of the event dev. >>> >> > + * Configuring ports with different thresholds can make >higher priority >>> >> > + * traffic less likely to be backpressured. >>> >> > + * For example, a port used to inject NIC Rx packets into >the event dev >>> >> > + * can have a lower threshold so as not to overwhelm the >device, >>> >> > + * while ports used for worker pools can have a higher >threshold. >>> >> > + * This value cannot exceed the *nb_events_limit* >>> >> > + * which was previously supplied to >rte_event_dev_configure(). >>> >> > + * This should be set to '-1' for *open system*. >>> >> > + */ >>> >> > + uint16_t dequeue_depth; >>> >> > + /**< Configure number of bulk dequeues for this event >port. >>> >> > + * This value cannot exceed the >*nb_event_port_dequeue_depth* >>> >> > + * which previously supplied to rte_event_dev_configure(). >>> >> > + * Ignored when device is not >RTE_EVENT_DEV_CAP_BURST_MODE >>> >capable. >>> >> > + */ >>> >> > + uint16_t enqueue_depth; >>> >> > + /**< Configure number of bulk enqueues for this event >port. >>> >> > + * This value cannot exceed the >*nb_event_port_enqueue_depth* >>> >> > + * which previously supplied to rte_event_dev_configure(). >>> >> > + * Ignored when device is not >RTE_EVENT_DEV_CAP_BURST_MODE >>> >capable. >>> >> > + */ >>> >> > uint8_t disable_implicit_release; >>> >> > /**< Configure the port not to release outstanding events >in >>> >> > * rte_event_dev_dequeue_burst(). If true, all events >received through >>> >> > @@ -733,6 +911,14 @@ struct rte_event_port_conf { >>> >> > rte_event_port_default_conf_get(uint8_t dev_id, uint8_t >port_id, >>> >> > struct rte_event_port_conf *port_conf); >>> >> > >>> >> > +int >>> >> > +rte_event_port_default_conf_get_v20(uint8_t dev_id, uint8_t >port_id, >>> >> > + struct rte_event_port_conf_v20 *port_conf); >>> >> > + >>> >> > +int >>> >> > +rte_event_port_default_conf_get_v21(uint8_t dev_id, uint8_t >port_id, >>> >> > + struct rte_event_port_conf *port_conf); >>> >> >>> >> Hi Timothy, >>> >> >>> >> + ABI Maintainers (Ray, Neil) >>> >> >>> >> # As per my understanding, the structures can not be versioned, >only >>> >> function can be versioned. >>> >> i.e we can not make any change to " struct rte_event_port_conf" >>> >> >>> >> # We have a similar case with ethdev and it deferred to next >release v20.11 >>> >> https://urldefense.proofpoint.com/v2/url?u=http- >3A__patches.dpdk.org_patch_69113_&d=DwIGaQ&c=nKjWec2b6R0mO >yPaz7xtfQ&r=1cjuAHrGh745jHNmj2fD85sUMIJ2IPIDsIJzo6FN6Z0&m=lL7 >dDlN7ICIpENvIB7_El27UclXA2tJLdOwbsirg1Dw&s=CNmSXDDn28U- >OjEAaZgJI_A2fDmMKM6zb12sIE9L-Io&e= >>> >> >>> >> Regarding the API changes: >>> >> # The slow path changes general looks good to me. I will review >the >>> >> next level in the coming days >>> >> # The following fast path changes bothers to me. Could you share >more >>> >> details on below change? >>> >> >>> >> diff --git a/app/test-eventdev/test_order_atq.c >>> >> b/app/test-eventdev/test_order_atq.c >>> >> index 3366cfc..8246b96 100644 >>> >> --- a/app/test-eventdev/test_order_atq.c >>> >> +++ b/app/test-eventdev/test_order_atq.c >>> >> @@ -34,6 +34,8 @@ >>> >> continue; >>> >> } >>> >> >>> >> + ev.flow_id = ev.mbuf->udata64; >>> >> + >>> >> # Since RC1 is near, I am not sure how to accommodate the API >changes >>> >> now and sort out ABI stuffs. >>> >> # Other concern is eventdev spec get bloated with versioning files >>> >> just for ONE release as 20.11 will be OK to change the ABI. >>> >> # While we discuss the API change, Please send deprecation >notice for >>> >> ABI change for 20.11, >>> >> so that there is no ambiguity of this patch for the 20.11 release. >>> >> >>> >> Hello Jerin, >>> >> >>> >> Thank you for the review comments. >>> >> >>> >> With regard to your comments regarding the fast path flow_id >change, the >>Intel >>> >DLB hardware >>> >> is not capable of transferring the flow_id as part of the event >itself. We >>> >therefore require a mechanism >>> >> to accomplish this. What we have done to work around this is to >require the >>> >application to embed the flow_id >>> >> within the data payload. The new flag, #define >>> >RTE_EVENT_DEV_CAP_CARRY_FLOW_ID (1ULL << 9), can be used >>> >> by applications to determine if they need to embed the flow_id, >or if its >>> >automatically propagated and present in the >>> >> received event. >>> >> >>> >> What we should have done is to wrap the assignment with a >conditional. >>> >> >>> >> if (!(device_capability_flags & >RTE_EVENT_DEV_CAP_CARRY_FLOW_ID)) >>> >> ev.flow_id = ev.mbuf->udata64; >>> > >>> >Two problems with this approach, >>> >1) we are assuming mbuf udata64 field is available for DLB driver >>> >2) It won't work with another adapter, eventdev has no >dependency with mbuf >>> > >>> >>> This snippet is not intended to suggest that udata64 always be used >to store the >>flow ID, but as an example of how an application could do it. Some >applications >>won’t need to carry the flow ID through; others can select an unused >field in the >>event data (e.g. hash.rss or udata64 if using mbufs), or (worst-case) >re-generate >>the flow ID in pipeline stages that require it. >> >>OK. >>> >>> >Question: >>> >1) In the case of DLB hardware, on dequeue(), what HW returns? is >it >>> >only event pointer and not have any other metadata like >schedule_type >>> >etc. >>> > >>> >>> The DLB device provides a 16B “queue entry” that consists of: >>> >>> * 8B event data >>> * Queue ID >>> * Priority >>> * Scheduling type >>> * 19 bits of carried-through data >>> * Assorted error/debug/reserved bits that are set by the device >(not carried- >>through) >>> >>> For the carried-through 19b, we use 12b for event_type and >sub_event_type. >> >>I can only think of TWO options to help >>1) Since event pointer always cache aligned, You could grab LSB >>6bits(2^6 = 64B ) and 7 bits from (19b - 12b) carried through >>structure >>2) Have separate mempool driver using existing drivers, ie "event >>pointer" + or - some offset have any amount of custom data. >> > >We can't guarantee that the event will contain a pointer -- it's possible >that 8B is inline data (i.e. struct rte_event's u64 field). > >It's really an application decision -- for example an app could allocate >space in the 'mbuf private data' to store the flow ID, if the event device >lacks that carry-flow-ID capability and the other mbuf fields can't be >used for whatever reason. >We modified the tests, sample apps to show how this might be done, >not necessarily how it must be done. > >> >>> >>> > >>> >> >>> >> This would minimize/eliminate any performance impact due to >the >>processor's >>> >branch prediction logic. >> >>I think, If we need to change common fastpath, better we need to >make >>it template to create code for compile-time to have absolute zero >>overhead >>and use runtime. >>See app/test-eventdev/test_order_atq.c: function: worker_wrapper() >>_create_ worker at compile time based on runtime capability. >> > >Yes, that would be perfect. Thanks for the example! Just to add instead of having if and else using a jumptbl would be much cleaner Ex. const pipeline_atq_worker_t pipeline_atq_worker_single_stage[2][2][2] = { [0][0] = pipeline_atq_worker_single_stage_fwd, [0][1] = pipeline_atq_worker_single_stage_tx, [1][0] = pipeline_atq_worker_single_stage_burst_fwd, [1][1] = pipeline_atq_worker_single_stage_burst_tx, }; return (pipeline_atq_worker_single_stage[burst][internal_port])(arg); > >> >> >>> >> The assignment then becomes in essence a NOOP for all event >devices that >>are >>> >capable of carrying the flow_id as part of the event payload itself. >>> >> >>> >> Thanks, >>> >> Tim >>> >> >>> >> >>> >> >>> >> Thanks, >>> >> Tim
next prev parent reply other threads:[~2020-06-30 20:40 UTC|newest] Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-06-27 4:37 [dpdk-dev] [PATCH 00/27] event/dlb Intel DLB PMD Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 01/27] eventdev: dlb upstream prerequisites Tim McDaniel 2020-06-27 7:44 ` Jerin Jacob 2020-06-29 19:30 ` McDaniel, Timothy 2020-06-30 4:21 ` Jerin Jacob 2020-06-30 15:37 ` McDaniel, Timothy 2020-06-30 15:57 ` Jerin Jacob 2020-06-30 19:26 ` McDaniel, Timothy 2020-06-30 20:40 ` Pavan Nikhilesh Bhagavatula [this message] 2020-06-30 21:07 ` McDaniel, Timothy 2020-07-01 4:50 ` Jerin Jacob 2020-07-01 16:48 ` McDaniel, Timothy 2020-06-30 11:22 ` Kinsella, Ray 2020-06-30 11:30 ` Jerin Jacob 2020-06-30 11:36 ` Kinsella, Ray 2020-06-30 12:14 ` Jerin Jacob 2020-07-02 15:21 ` Kinsella, Ray 2020-07-02 16:35 ` McDaniel, Timothy 2020-06-27 4:37 ` [dpdk-dev] [PATCH 02/27] eventdev: do not pass disable_implicit_release bit to trace macro Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 03/27] event/dlb: add shared code version 10.7.9 Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 04/27] event/dlb: add make and meson build infrastructure Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 05/27] event/dlb: add DLB documentation Tim McDaniel 2020-07-09 3:29 ` Eads, Gage 2020-06-27 4:37 ` [dpdk-dev] [PATCH 06/27] event/dlb: add dynamic logging Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 07/27] event/dlb: add private data structures and constants Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 08/27] event/dlb: add definitions shared with LKM or shared code Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 09/27] event/dlb: add inline functions used in multiple files Tim McDaniel 2020-07-07 12:02 ` Bruce Richardson 2020-07-07 14:33 ` McDaniel, Timothy 2020-06-27 4:37 ` [dpdk-dev] [PATCH 10/27] event/dlb: add PFPMD-specific interface layer to shared code Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 11/27] event/dlb: add flexible PMD to device interfaces Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 12/27] event/dlb: add the PMD's public interfaces Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 13/27] event/dlb: add xstats support Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 14/27] event/dlb: add PMD self-tests Tim McDaniel 2020-07-10 20:42 ` Eads, Gage 2020-07-29 18:56 ` McDaniel, Timothy 2020-06-27 4:37 ` [dpdk-dev] [PATCH 15/27] event/dlb: add probe Tim McDaniel 2020-07-09 3:45 ` Eads, Gage 2020-06-27 4:37 ` [dpdk-dev] [PATCH 16/27] event/dlb: add infos_get and configure Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 17/27] event/dlb: add queue_def_conf and port_def_conf Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 18/27] event/dlb: add queue setup Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 19/27] event/dlb: add port_setup Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 20/27] event/dlb: add port_link Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 21/27] event/dlb: add queue_release and port_release Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 22/27] event/dlb: add port_unlink and port_unlinks_in_progress Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 23/27] event/dlb: add eventdev_start Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 24/27] event/dlb: add timeout_ticks, dump, xstats, and selftest Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 25/27] event/dlb: add enqueue and its burst variants Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 26/27] event/dlb: add dequeue, dequeue_burst, and variants Tim McDaniel 2020-06-27 4:37 ` [dpdk-dev] [PATCH 27/27] event/dlb: add eventdev_stop and eventdev_close Tim McDaniel [not found] <1593232671-5690-0-git-send-email-timothy.mcdaniel@intel.com> 2020-07-30 19:49 ` [dpdk-dev] [PATCH 00/27] Add Intel DLM PMD to 20.11 McDaniel, Timothy 2020-07-30 19:49 ` [dpdk-dev] [PATCH 01/27] eventdev: dlb upstream prerequisites McDaniel, Timothy 2020-08-11 17:44 ` Jerin Jacob -- strict thread matches above, loose matches on Subject: below -- 2020-06-12 21:24 [dpdk-dev] [PATCH 00/27] V1 event/dlb add Intel DLB PMD McDaniel, Timothy 2020-06-12 21:24 ` [dpdk-dev] [PATCH 01/27] eventdev: dlb upstream prerequisites McDaniel, Timothy 2020-06-13 3:59 ` Jerin Jacob 2020-06-13 10:43 ` Mattias Rönnblom 2020-06-18 15:51 ` McDaniel, Timothy 2020-06-18 15:44 ` McDaniel, Timothy
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