[dpdk-dev] [PATCH v5 09/20] event/sw: add worker core functions

Van Haaren, Harry harry.van.haaren at intel.com
Tue Mar 28 18:17:56 CEST 2017


> From: Jerin Jacob [mailto:jerin.jacob at caviumnetworks.com]
> Sent: Monday, March 27, 2017 2:51 PM
> To: Van Haaren, Harry <harry.van.haaren at intel.com>
> Cc: dev at dpdk.org; Richardson, Bruce <bruce.richardson at intel.com>; Eads, Gage
> <gage.eads at intel.com>
> Subject: Re: [PATCH v5 09/20] event/sw: add worker core functions
> 
> On Fri, Mar 24, 2017 at 04:53:04PM +0000, Harry van Haaren wrote:
> > From: Bruce Richardson <bruce.richardson at intel.com>
> >
> > add the event enqueue, dequeue and release functions to the eventdev.
> > These also include tracking of stats for observability in the load of
> > the scheduler.
> > Internally in the enqueue function, the various types of enqueue
> > operations, to forward an existing event, to send a new event, to
> > drop a previous event, are converted to a series of flags which will
> > be used by the scheduler code to perform the needed actions for that
> > event.
> >
> > Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
> > Signed-off-by: Gage Eads <gage.eads at intel.com>
> > Signed-off-by: Harry van Haaren <harry.van.haaren at intel.com>
> > ---
> >  drivers/event/sw/Makefile          |   1 +
> >  drivers/event/sw/sw_evdev.c        |   5 +
> >  drivers/event/sw/sw_evdev.h        |  32 +++++++
> >  drivers/event/sw/sw_evdev_worker.c | 188 +++++++++++++++++++++++++++++++++++++
> >  4 files changed, 226 insertions(+)
> >  create mode 100644 drivers/event/sw/sw_evdev_worker.c
> >

<snip>

> > @@ -550,6 +551,10 @@ sw_probe(const char *name, const char *params)
> >  		return -EFAULT;
> >  	}
> >  	dev->dev_ops = &evdev_sw_ops;
> > +	dev->enqueue = sw_event_enqueue;
> > +	dev->enqueue_burst = sw_event_enqueue_burst;
> > +	dev->dequeue = sw_event_dequeue;
> > +	dev->dequeue_burst = sw_event_dequeue_burst;
> 
> Is all the code in the sw_probe() valid for multi process? If not, after
> function pointer assignment it can return[1] from sw_probe. Just like
> another PMD's, we will support configuration API and fastpath API in primary
> process and secondary process will be limited to fast path functions.
> 
> [1]
>         if (rte_eal_process_type() != RTE_PROC_PRIMARY)
> 		return 0;


Yes, will be fixed in v6.


> >  	sw = dev->data->dev_private;
> >  	sw->data = dev->data;
> > diff --git a/drivers/event/sw/sw_evdev.h b/drivers/event/sw/sw_evdev.h
> > index f5515e1..ab372fd 100644
> > --- a/drivers/event/sw/sw_evdev.h
> > +++ b/drivers/event/sw/sw_evdev.h
> > @@ -55,12 +55,36 @@
> >  #define SCHED_DEQUEUE_BURST_SIZE 32
> >
> > +
> > +static inline void
> > +sw_event_release(struct sw_port *p, uint8_t index)
> > +{
> > +	/*
> > +	 * Drops the next outstanding event in our history. Used on dequeue
> > +	 * to clear any history before dequeuing more events.
> > +	 */
> > +	RTE_SET_USED(index);
> > +
> > +	/* create drop message */
> > +	struct rte_event ev = {
> > +		.op = sw_qe_flag_map[RTE_EVENT_OP_RELEASE],
> > +	};
> > +
> > +	uint16_t free_count;
> > +	qe_ring_enqueue_burst(p->rx_worker_ring, &ev, 1, &free_count);
> > +
> > +	/* each release returns one credit */
> > +	p->outstanding_releases--;
> > +	p->inflight_credits++;
> > +}
> > +
> > +uint16_t
> > +sw_event_enqueue_burst(void *port, const struct rte_event ev[], uint16_t num)
> > +{
> > +	int32_t i;
> > +	uint8_t new_ops[PORT_ENQUEUE_MAX_BURST_SIZE];
> > +	struct sw_port *p = port;
> > +	struct sw_evdev *sw = (void *)p->sw;
> > +	uint32_t sw_inflights = rte_atomic32_read(&sw->inflights);
> > +
> > +	if (p->inflight_max < sw_inflights)
> > +		return 0;
> 
> likely and unlikely attributes are missing in fastpath functions.
> Worth to consider in using those in worker file.


Initial (obvious ones) done in v6. Perhaps a candidate for future patches after initial merge, as these are only performance improvements, not functional.


> > +uint16_t
> > +sw_event_dequeue_burst(void *port, struct rte_event *ev, uint16_t num,
> > +		uint64_t wait)
> > +{
> > +	RTE_SET_USED(wait);
> > +	struct sw_port *p = (void *)port;
> > +	struct sw_evdev *sw = (void *)p->sw;
> > +	struct qe_ring *ring = p->cq_worker_ring;
> > +	uint32_t credit_update_quanta = sw->credit_update_quanta;
> > +
> > +	/* check that all previous dequeues have been released */
> > +	if (!p->is_directed) {
> > +		uint16_t out_rels = p->outstanding_releases;
> > +		uint16_t i;
> > +		for (i = 0; i < out_rels; i++)
> > +			sw_event_release(p, i);
> > +	}
> > +
> > +	/* Intel modification: may not be in final API */
> > +	if (ev == 0)
> > +		return 0;
> 
> May be we can remove this one in fastpath. Maybe under DEBUG in common code
> we can add this.


Done, removed in v6.


<snip to end>



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