From: "Van Haaren, Harry" <harry.van.haaren@intel.com>
To: Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>,
"jerin.jacob@caviumnetworks.com" <jerin.jacob@caviumnetworks.com>,
"santosh.shukla@caviumnetworks.com"
<santosh.shukla@caviumnetworks.com>,
"Eads, Gage" <gage.eads@intel.com>,
"hemant.agrawal@nxp.com" <hemant.agrawal@nxp.com>,
"nipun.gupta@nxp.com" <nipun.gupta@nxp.com>,
"Ma, Liang J" <liang.j.ma@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH v3 09/12] app/eventdev: add pipeline queue worker functions
Date: Thu, 11 Jan 2018 12:17:38 +0000 [thread overview]
Message-ID: <E923DB57A917B54B9182A2E928D00FA650FED7FA@IRSMSX102.ger.corp.intel.com> (raw)
In-Reply-To: <20180110201710.3uolm2hwzwcowoif@Pavan-LT>
> From: Pavan Nikhilesh [mailto:pbhagavatula@caviumnetworks.com]
> Sent: Wednesday, January 10, 2018 8:17 PM
> To: Van Haaren, Harry <harry.van.haaren@intel.com>;
> jerin.jacob@caviumnetworks.com; santosh.shukla@caviumnetworks.com; Eads,
> Gage <gage.eads@intel.com>; hemant.agrawal@nxp.com; nipun.gupta@nxp.com; Ma,
> Liang J <liang.j.ma@intel.com>
> Cc: dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v3 09/12] app/eventdev: add pipeline queue
> worker functions
>
> On Wed, Jan 10, 2018 at 04:53:53PM +0000, Van Haaren, Harry wrote:
> > Replying to self...
> >
> > > -----Original Message-----
> > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Van Haaren, Harry
> > > Sent: Wednesday, January 10, 2018 4:45 PM
> > > To: Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>;
> > > jerin.jacob@caviumnetworks.com; santosh.shukla@caviumnetworks.com; Eads,
> > > Gage <gage.eads@intel.com>; hemant.agrawal@nxp.com; nipun.gupta@nxp.com;
> Ma,
> > > Liang J <liang.j.ma@intel.com>
> > > Cc: dev@dpdk.org
> > > Subject: Re: [dpdk-dev] [PATCH v3 09/12] app/eventdev: add pipeline
> queue
> > > worker functions
> > >
> > > > From: Pavan Nikhilesh [mailto:pbhagavatula@caviumnetworks.com]
> > > > Sent: Wednesday, January 10, 2018 2:52 PM
> > > > To: jerin.jacob@caviumnetworks.com; santosh.shukla@caviumnetworks.com;
> Van
> > > > Haaren, Harry <harry.van.haaren@intel.com>; Eads, Gage
> > > > <gage.eads@intel.com>; hemant.agrawal@nxp.com; nipun.gupta@nxp.com;
> Ma,
> > > > Liang J <liang.j.ma@intel.com>
> > > > Cc: dev@dpdk.org; Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>
> > > > Subject: [dpdk-dev] [PATCH v3 09/12] app/eventdev: add pipeline queue
> > > worker
> > > > functions
> > > >
> > >
> > > <snip>
> > >
> > >
> > > > +static __rte_always_inline void
> > > > +pipeline_tx_pkt_safe(struct rte_mbuf *mbuf)
> > > > +{
> > > > + while (rte_eth_tx_burst(mbuf->port, 0, &mbuf, 1) != 1)
> > > > + rte_pause();
> > > > +}
> > >
> > > re safe, see comment below
> > >
> > > > +
> > > > +static __rte_always_inline void
> > > > +pipeline_tx_pkt_unsafe(struct rte_mbuf *mbuf, struct test_pipeline
> *t)
> > > > +{
> > > > + rte_spinlock_t *lk = &t->tx_lk[mbuf->port];
> > > > +
> > > > + rte_spinlock_lock(lk);
> > > > + pipeline_tx_pkt_safe(mbuf);
> > > > + rte_spinlock_unlock(lk);
> > > > +}
> > >
> > > IIRC usually the "Safe" version of a function has extra
> locks/protection,
> > > while the "normal" version has better performance, but less-error-
> checking.
> > >
> > > Here, the "unsafe" function does the extra locking. If looking from the
> HW
> > > POV, that makes sense, but I think its inverted from most existing
> code...
> > >
> > > Happy to be proved wrong here .. ?
> > >
> > > <snip>
> >
> >
> > Thinking a little more about this, also in light of patch 11/12 of this
> series.
> >
> > The code here has a "safe" and "unsafe" version of TX. This involves
> adding a spinlock inside the code, which is being locked/unlocked before
> doing the actual TX action.
> >
> > I don't understand why this is necessary? DPDK's general stance on locking
> for data-path is DPDK functions do not provide locks, and that application
> level must implement thread-synchronization if it is required.
> >
> > In this case, the app/eventdev can be considered an App, but I don't like
> the idea of providing a sample application and code that duplicates core
> functionality with safe/unsafe versions..
> >
>
> Some PMD's (net/octeontx) have capability to do multi-thread safe Tx where
> no
> thread-synchronization is required. This is exposed via the offload flag
> 'DEV_TX_OFFLOAD_MT_LOCKFREE'.
Yes understood.
> So, the _safe Tx functions are selected based on the above offload
> capability
> and when the capability is absent _unsafe Tx functions are selected i.e.
> synchronized Tx via spin locks based on the Egress port id.
This part changes the current behavior of the sample app.
Currently there is a (SINGLE_LINK | ATOMIC) stage at the end of the pipeline, which performs this "many-to-one" action, allowing a single core to dequeue all TX traffic, and perform the TX operation in a lock-free manner.
Changing this to a locking mechanism is going to hurt performance on platforms that do not support TX_OFFLOAD_MT_LOCKFREE.
In my opinion, the correct fix is to alter the overall pipeline, and always use lockless TX. Examples below;
NO TX_OFFLOAD_MT_LOCKFREE:
Eth RX adapter -> stage 1 -> stage 2...(N-1) -> stage N -> stage TX (Atomic | SINGLE_LINK) -> eth TX
WITH TX_OFFLOAD_MT_LOCKFREE:
Eth RX adapter -> stage 1 -> stage 2...(N-1) -> stage N -> eth TX MT Capable
By configuring the pipeline based on MT_OFFLOAD_LOCKFREE capability flag, and adding the SINGLE_LINK at the end if required, we can support both models without resorting to locked TX functions.
I think this will lead to a cleaner and more performant solution.
<snip>
next prev parent reply other threads:[~2018-01-11 12:17 UTC|newest]
Thread overview: 122+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-30 7:24 [dpdk-dev] [PATCH 1/4] app/eventdev: modify ethdev setup to support Tx Pavan Nikhilesh
2017-11-30 7:24 ` [dpdk-dev] [PATCH 2/4] app/eventdev: add packet distribution logs Pavan Nikhilesh
2017-12-10 12:31 ` Jerin Jacob
2017-11-30 7:24 ` [dpdk-dev] [PATCH 3/4] app/eventdev: add perf pipeline test Pavan Nikhilesh
2017-11-30 17:15 ` Eads, Gage
2017-12-01 5:19 ` Pavan Nikhilesh Bhagavatula
2017-12-10 12:33 ` Jerin Jacob
2017-12-11 15:20 ` Pavan Nikhilesh Bhagavatula
2017-12-11 15:45 ` Jerin Jacob
2017-11-30 7:24 ` [dpdk-dev] [PATCH 4/4] doc: add perf pipeline test in eventdev test guide Pavan Nikhilesh
2017-12-18 21:43 ` [dpdk-dev] [PATCH v2 01/12] app/eventdev: add packet distribution logs Pavan Nikhilesh
2017-12-18 21:43 ` [dpdk-dev] [PATCH v2 02/12] app/eventdev: add pipeline test setup and destroy Pavan Nikhilesh
2018-01-08 14:04 ` Jerin Jacob
2017-12-18 21:43 ` [dpdk-dev] [PATCH v2 03/12] app/eventdev: add mempool " Pavan Nikhilesh
2018-01-08 14:06 ` Jerin Jacob
2017-12-18 21:43 ` [dpdk-dev] [PATCH v2 04/12] app/eventdev: add pipeline opt dump and check functions Pavan Nikhilesh
2017-12-18 21:43 ` [dpdk-dev] [PATCH v2 05/12] app/eventdev: add perf ethport setup and destroy Pavan Nikhilesh
2018-01-08 14:10 ` Jerin Jacob
2017-12-18 21:43 ` [dpdk-dev] [PATCH v2 06/12] app/eventdev: add event port setup and Rx adapter setup Pavan Nikhilesh
2017-12-18 21:44 ` [dpdk-dev] [PATCH v2 07/12] app/eventdev: launch pipeline lcores Pavan Nikhilesh
2017-12-18 21:44 ` [dpdk-dev] [PATCH v2 08/12] app/eventdev: add pipeline queue test Pavan Nikhilesh
2017-12-18 21:44 ` [dpdk-dev] [PATCH v2 09/12] app/eventdev: add pipeline queue worker functions Pavan Nikhilesh
2017-12-18 21:44 ` [dpdk-dev] [PATCH v2 10/12] app/eventdev: add pipeline atq test Pavan Nikhilesh
2018-01-08 14:15 ` Jerin Jacob
2017-12-18 21:44 ` [dpdk-dev] [PATCH v2 11/12] app/eventdev: add pipeline atq worker functions Pavan Nikhilesh
2017-12-18 21:44 ` [dpdk-dev] [PATCH v2 12/12] doc: add pipeline test in eventdev test guide Pavan Nikhilesh
2018-01-10 14:51 ` [dpdk-dev] [PATCH v3 01/12] app/eventdev: add packet distribution logs Pavan Nikhilesh
2018-01-10 14:51 ` [dpdk-dev] [PATCH v3 02/12] app/eventdev: add pipeline test setup and destroy Pavan Nikhilesh
2018-01-10 14:51 ` [dpdk-dev] [PATCH v3 03/12] app/eventdev: add mempool " Pavan Nikhilesh
2018-01-10 14:51 ` [dpdk-dev] [PATCH v3 04/12] app/eventdev: add pipeline opt dump and check functions Pavan Nikhilesh
2018-01-10 14:51 ` [dpdk-dev] [PATCH v3 05/12] app/eventdev: add perf ethport setup and destroy Pavan Nikhilesh
2018-01-10 14:51 ` [dpdk-dev] [PATCH v3 06/12] app/eventdev: add event port setup and Rx adapter setup Pavan Nikhilesh
2018-01-10 14:51 ` [dpdk-dev] [PATCH v3 07/12] app/eventdev: launch pipeline lcores Pavan Nikhilesh
2018-01-10 14:51 ` [dpdk-dev] [PATCH v3 08/12] app/eventdev: add pipeline queue test Pavan Nikhilesh
2018-01-10 16:38 ` Van Haaren, Harry
2018-01-10 20:01 ` Pavan Nikhilesh
2018-01-15 10:17 ` Van Haaren, Harry
2018-01-10 14:51 ` [dpdk-dev] [PATCH v3 09/12] app/eventdev: add pipeline queue worker functions Pavan Nikhilesh
2018-01-10 16:45 ` Van Haaren, Harry
2018-01-10 16:53 ` Van Haaren, Harry
2018-01-10 20:17 ` Pavan Nikhilesh
2018-01-11 12:17 ` Van Haaren, Harry [this message]
2018-01-11 13:52 ` Pavan Nikhilesh
2018-01-11 15:47 ` Van Haaren, Harry
2018-01-10 14:51 ` [dpdk-dev] [PATCH v3 10/12] app/eventdev: add pipeline atq test Pavan Nikhilesh
2018-01-10 14:51 ` [dpdk-dev] [PATCH v3 11/12] app/eventdev: add pipeline atq worker functions Pavan Nikhilesh
2018-01-10 14:51 ` [dpdk-dev] [PATCH v3 12/12] doc: add pipeline test in eventdev test guide Pavan Nikhilesh
2018-01-12 16:44 ` [dpdk-dev] [PATCH v4 01/13] app/eventdev: add packet distribution logs Pavan Nikhilesh
2018-01-12 16:44 ` [dpdk-dev] [PATCH v4 02/13] app/eventdev: add pipeline test setup and destroy Pavan Nikhilesh
2018-01-12 16:44 ` [dpdk-dev] [PATCH v4 03/13] app/eventdev: add mempool " Pavan Nikhilesh
2018-01-12 16:44 ` [dpdk-dev] [PATCH v4 04/13] app/eventdev: add pipeline opt dump and check functions Pavan Nikhilesh
2018-01-16 11:54 ` Van Haaren, Harry
2018-01-17 17:19 ` Jerin Jacob
2018-01-12 16:44 ` [dpdk-dev] [PATCH v4 05/13] app/eventdev: add pipeline ethport setup and destroy Pavan Nikhilesh
2018-01-16 11:54 ` Van Haaren, Harry
2018-01-12 16:44 ` [dpdk-dev] [PATCH v4 06/13] app/eventdev: add event port setup and Rx adapter setup Pavan Nikhilesh
2018-01-16 11:54 ` Van Haaren, Harry
2018-01-12 16:44 ` [dpdk-dev] [PATCH v4 07/13] app/eventdev: add Tx service setup Pavan Nikhilesh
2018-01-16 11:57 ` Van Haaren, Harry
2018-01-12 16:44 ` [dpdk-dev] [PATCH v4 08/13] app/eventdev: launch pipeline lcores Pavan Nikhilesh
2018-01-16 11:57 ` Van Haaren, Harry
2018-01-12 16:44 ` [dpdk-dev] [PATCH v4 09/13] app/eventdev: add pipeline queue test Pavan Nikhilesh
2018-01-16 11:58 ` Van Haaren, Harry
2018-01-12 16:44 ` [dpdk-dev] [PATCH v4 10/13] app/eventdev: add pipeline queue worker functions Pavan Nikhilesh
2018-01-16 12:05 ` Van Haaren, Harry
2018-01-16 12:31 ` Pavan Nikhilesh
2018-01-12 16:44 ` [dpdk-dev] [PATCH v4 11/13] app/eventdev: add pipeline atq test Pavan Nikhilesh
2018-01-16 12:06 ` Van Haaren, Harry
2018-01-12 16:44 ` [dpdk-dev] [PATCH v4 12/13] app/eventdev: add pipeline atq worker functions Pavan Nikhilesh
2018-01-16 12:06 ` Van Haaren, Harry
2018-01-12 16:44 ` [dpdk-dev] [PATCH v4 13/13] doc: add pipeline test in eventdev test guide Pavan Nikhilesh
2018-01-15 11:16 ` Kovacevic, Marko
2018-01-15 16:16 ` Jerin Jacob
2018-01-16 15:17 ` [dpdk-dev] [PATCH v5 01/14] app/eventdev: add packet distribution logs Pavan Nikhilesh
2018-01-16 15:17 ` [dpdk-dev] [PATCH v5 02/14] app/eventdev: add pipeline test setup and destroy Pavan Nikhilesh
2018-01-16 15:17 ` [dpdk-dev] [PATCH v5 03/14] app/eventdev: add mempool " Pavan Nikhilesh
2018-01-16 15:17 ` [dpdk-dev] [PATCH v5 04/14] app/eventdev: add pipeline opt dump and check functions Pavan Nikhilesh
2018-01-16 15:17 ` [dpdk-dev] [PATCH v5 05/14] app/eventdev: add pipeline ethport setup and destroy Pavan Nikhilesh
2018-01-16 15:17 ` [dpdk-dev] [PATCH v5 06/14] app/eventdev: add event port setup and Rx adapter setup Pavan Nikhilesh
2018-01-16 15:17 ` [dpdk-dev] [PATCH v5 07/14] app/eventdev: add Tx service setup Pavan Nikhilesh
2018-01-16 15:17 ` [dpdk-dev] [PATCH v5 08/14] app/eventdev: launch pipeline lcores Pavan Nikhilesh
2018-01-16 15:17 ` [dpdk-dev] [PATCH v5 09/14] app/eventdev: add pipeline queue test Pavan Nikhilesh
2018-01-16 15:17 ` [dpdk-dev] [PATCH v5 10/14] app/eventdev: add pipeline queue worker functions Pavan Nikhilesh
2018-01-16 15:17 ` [dpdk-dev] [PATCH v5 11/14] app/eventdev: add pipeline atq test Pavan Nikhilesh
2018-01-16 15:17 ` [dpdk-dev] [PATCH v5 12/14] app/eventdev: add pipeline atq worker functions Pavan Nikhilesh
2018-01-16 15:17 ` [dpdk-dev] [PATCH v5 13/14] doc: add pipeline test in eventdev test guide Pavan Nikhilesh
2018-01-16 15:20 ` [dpdk-dev] [PATCH v5 14/14] doc: update 18.02 release notes Pavan Nikhilesh
2018-01-16 15:39 ` [dpdk-dev] [PATCH v6 01/14] app/eventdev: add packet distribution logs Pavan Nikhilesh
2018-01-16 15:39 ` [dpdk-dev] [PATCH v6 02/14] app/eventdev: add pipeline test setup and destroy Pavan Nikhilesh
2018-01-16 15:39 ` [dpdk-dev] [PATCH v6 03/14] app/eventdev: add mempool " Pavan Nikhilesh
2018-01-16 15:39 ` [dpdk-dev] [PATCH v6 04/14] app/eventdev: add pipeline opt dump and check functions Pavan Nikhilesh
2018-01-16 15:39 ` [dpdk-dev] [PATCH v6 05/14] app/eventdev: add pipeline ethport setup and destroy Pavan Nikhilesh
2018-01-16 15:39 ` [dpdk-dev] [PATCH v6 06/14] app/eventdev: add event port setup and Rx adapter setup Pavan Nikhilesh
2018-01-16 15:39 ` [dpdk-dev] [PATCH v6 07/14] app/eventdev: add Tx service setup Pavan Nikhilesh
2018-01-16 15:39 ` [dpdk-dev] [PATCH v6 08/14] app/eventdev: launch pipeline lcores Pavan Nikhilesh
2018-01-16 15:39 ` [dpdk-dev] [PATCH v6 09/14] app/eventdev: add pipeline queue test Pavan Nikhilesh
2018-01-16 15:39 ` [dpdk-dev] [PATCH v6 10/14] app/eventdev: add pipeline queue worker functions Pavan Nikhilesh
2018-01-16 15:40 ` [dpdk-dev] [PATCH v6 11/14] app/eventdev: add pipeline atq test Pavan Nikhilesh
2018-01-16 15:40 ` [dpdk-dev] [PATCH v6 12/14] app/eventdev: add pipeline atq worker functions Pavan Nikhilesh
2018-01-16 15:40 ` [dpdk-dev] [PATCH v6 13/14] doc: add pipeline test in eventdev test guide Pavan Nikhilesh
2018-01-16 15:40 ` [dpdk-dev] [PATCH v6 14/14] doc: update 18.02 release notes Pavan Nikhilesh
2018-01-16 16:04 ` Mcnamara, John
2018-01-16 17:51 ` Pavan Nikhilesh
2018-01-16 17:45 ` [dpdk-dev] [PATCH v7 01/15] app/eventdev: add packet distribution logs Pavan Nikhilesh
2018-01-16 17:45 ` [dpdk-dev] [PATCH v7 02/15] app/eventdev: add pipeline test setup and destroy Pavan Nikhilesh
2018-01-16 17:45 ` [dpdk-dev] [PATCH v7 03/15] app/eventdev: add mempool " Pavan Nikhilesh
2018-01-16 17:45 ` [dpdk-dev] [PATCH v7 04/15] app/eventdev: add pipeline opt dump and check functions Pavan Nikhilesh
2018-01-16 17:45 ` [dpdk-dev] [PATCH v7 05/15] app/eventdev: add pipeline ethport setup and destroy Pavan Nikhilesh
2018-01-16 17:45 ` [dpdk-dev] [PATCH v7 06/15] app/eventdev: add event port setup and Rx adapter setup Pavan Nikhilesh
2018-01-16 17:45 ` [dpdk-dev] [PATCH v7 07/15] app/eventdev: add Tx service setup Pavan Nikhilesh
2018-01-16 17:46 ` [dpdk-dev] [PATCH v7 08/15] app/eventdev: launch pipeline lcores Pavan Nikhilesh
2018-01-16 17:46 ` [dpdk-dev] [PATCH v7 09/15] app/eventdev: add pipeline queue test Pavan Nikhilesh
2018-01-16 17:46 ` [dpdk-dev] [PATCH v7 10/15] app/eventdev: add pipeline queue worker functions Pavan Nikhilesh
2018-01-16 17:46 ` [dpdk-dev] [PATCH v7 11/15] app/eventdev: add pipeline atq test Pavan Nikhilesh
2018-01-16 17:46 ` [dpdk-dev] [PATCH v7 12/15] app/eventdev: add pipeline atq worker functions Pavan Nikhilesh
2018-01-16 17:46 ` [dpdk-dev] [PATCH v7 13/15] doc: add pipeline queue test in eventdev test guide Pavan Nikhilesh
[not found] ` <CY4PR07MB3464D865D1B9CA42596A242380E90@CY4PR07MB3464.namprd07.prod.outlook.com>
2018-01-17 17:12 ` Mcnamara, John
2018-01-16 17:46 ` [dpdk-dev] [PATCH v7 14/15] doc: add pipeline atq " Pavan Nikhilesh
[not found] ` <CY4PR07MB346409AFA54FC1836195EA0A80E90@CY4PR07MB3464.namprd07.prod.outlook.com>
2018-01-17 17:12 ` Mcnamara, John
2018-01-16 17:46 ` [dpdk-dev] [PATCH v7 15/15] doc: update 18.02 release notes Pavan Nikhilesh
2018-01-17 5:47 ` [dpdk-dev] Fw: " Bhagavatula, Pavan
2018-01-17 17:14 ` [dpdk-dev] " Mcnamara, John
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