Re: [dpdk-dev] [PATCH v5 1/3] examples/eventdev_pipeline: added sample app

[Jerin Jacob <jerin.jacob@caviumnetworks.com>]

-----Original Message-----
> Date: Tue, 4 Jul 2017 08:55:25 +0100
> From: "Hunt, David" <david.hunt@intel.com>
> To: Jerin Jacob <jerin.jacob@caviumnetworks.com>
> CC: dev@dpdk.org, harry.van.haaren@intel.com, Gage Eads
>  <gage.eads@intel.com>, Bruce Richardson <bruce.richardson@intel.com>
> Subject: Re: [PATCH v5 1/3] examples/eventdev_pipeline: added sample app
> User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101
>  Thunderbird/45.8.0
> 
> Hi Jerin,

Hi David,

I have checked the v6. Some comments below.

> 
> 
> On 3/7/2017 4:57 AM, Jerin Jacob wrote:
> > -----Original Message-----
> > > From: Harry van Haaren<harry.van.haaren@intel.com>
> > > 
> > > This commit adds a sample app for the eventdev library.
> > > The app has been tested with DPDK 17.05-rc2, hence this
> > > release (or later) is recommended.
> > > 
> > > The sample app showcases a pipeline processing use-case,
> > > with event scheduling and processing defined per stage.
> > > The application receives traffic as normal, with each
> > > packet traversing the pipeline. Once the packet has
> > > been processed by each of the pipeline stages, it is
> > > transmitted again.
> > > 
> > > The app provides a framework to utilize cores for a single
> > > role or multiple roles. Examples of roles are the RX core,
> > > TX core, Scheduling core (in the case of the event/sw PMD),
> > > and worker cores.
> > > 
> > > Various flags are available to configure numbers of stages,
> > > cycles of work at each stage, type of scheduling, number of
> > > worker cores, queue depths etc. For a full explaination,
> > > please refer to the documentation.
> > A few comments on bugs and "to avoid the future rework on base code when
> > HW PMD is introduced". As we agreed, We will keep the functionality intact to
> > provide an application to test ethdev + eventdev with _SW PMD_ for 17.08
> > 
> 
> Sure OK. I will Address.
> 
> > > ---
> > >   examples/Makefile                   |   2 +
> > >   examples/eventdev_pipeline/Makefile |  49 ++
> > >   examples/eventdev_pipeline/main.c   | 999 ++++++++++++++++++++++++++++++++++++
> > >   3 files changed, 1050 insertions(+)
> > >   create mode 100644 examples/eventdev_pipeline/Makefile
> > >   create mode 100644 examples/eventdev_pipeline/main.c
> > Do we need to update the MAINTAINERS file?
> 
> Updated
> > > diff --git a/examples/Makefile b/examples/Makefile
> > > index 6298626..a6dcc2b 100644
> > > --- a/examples/Makefile
> > > +++ b/examples/Makefile
> > > @@ -100,4 +100,6 @@ $(info vm_power_manager requires libvirt >= 0.9.3)
> > >   endif
> > >   endif
> > > +DIRS-y += eventdev_pipeline
> > Can you change to eventdev_pipeline_sw_pmd to emphasis on the scope.
> > We will rename to eventdev_pipeline once it working effectively on both SW and HW
> > PMD with ethdev.
> 
> OK, I've updated the directory, app name and relevant docs across the board
> so they're all
> eventdev_pipeline_sw_pmd. This should make it clear to anyone using it that
> it's for the
> sw_pmd only, and an updated version will be provided later.
> 
> 
> > > +
> > >   include $(RTE_SDK)/mk/rte.extsubdir.mk
> > > diff --git a/examples/eventdev_pipeline/Makefile b/examples/eventdev_pipeline/Makefile
> > > new file mode 100644
> > > index 0000000..4c26e15
> > > --- /dev/null
> > > +++ b/examples/eventdev_pipeline/Makefile
> > > @@ -0,0 +1,49 @@
> > > +#   BSD LICENSE
> > > +#
> > > +#   Copyright(c) 2016 Intel Corporation. All rights reserved.
> > 2016-2017
> 
> Done.
> 
> > > +#
> > > +#   Redistribution and use in source and binary forms, with or without
> > > +#   modification, are permitted provided that the following conditions
> > > +#   are met:
> > > +#
> > > +
> > > +static unsigned int active_cores;
> > > +static unsigned int num_workers;
> > > +static long num_packets = (1L << 25); /* do ~32M packets */
> > > +static unsigned int num_fids = 512;
> > > +static unsigned int num_stages = 1;
> > > +static unsigned int worker_cq_depth = 16;

Any reason not move this to struct config_data?

> > > +static int queue_type = RTE_EVENT_QUEUE_CFG_ATOMIC_ONLY;
> > > +static int16_t next_qid[MAX_NUM_STAGES+1] = {-1};
> > > +static int16_t qid[MAX_NUM_STAGES] = {-1};
> > > +static int worker_cycles;

used in fastpath move to struct fastpath_data.

> > > +static int enable_queue_priorities;

struct config_data ?
> > > +
> > > +struct prod_data {
> > > +	uint8_t dev_id;
> > > +	uint8_t port_id;
> > > +	int32_t qid;
> > > +	unsigned int num_nic_ports;
> > > +} __rte_cache_aligned;
> > > +
> > > +struct cons_data {
> > > +	uint8_t dev_id;
> > > +	uint8_t port_id;
> > > +} __rte_cache_aligned;
> > > +
> > > +static struct prod_data prod_data;
> > > +static struct cons_data cons_data;
> > > +
> > > +struct worker_data {
> > > +	uint8_t dev_id;
> > > +	uint8_t port_id;
> > > +} __rte_cache_aligned;
> > > +
> > > +static unsigned int *enqueue_cnt;
> > > +static unsigned int *dequeue_cnt;
> > Not been consumed. Remove it.
> 
> Done.
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +
> > > +static inline void
> > > +work(struct rte_mbuf *m)
> > > +{
> > > +	struct ether_hdr *eth;
> > > +	struct ether_addr addr;
> > > +
> > > +	/* change mac addresses on packet (to use mbuf data) */
> > > +	eth = rte_pktmbuf_mtod(m, struct ether_hdr *);
> > > +	ether_addr_copy(&eth->d_addr, &addr);
> > > +	ether_addr_copy(&eth->s_addr, &eth->d_addr);
> > > +	ether_addr_copy(&addr, &eth->s_addr);
> > If it is even number of stages(say 2), Will mac swap be negated? as we are
> > swapping on each stage NOT in consumer?
> 
> The mac swap is just to touch the mbuf. It does not matter if it is negated.

Are you sure or I am missing something here? for example,If I add following piece
of code, irrespective number of stages it should send the same packet if
source packet is same. Right ?

But not happening as expected(Check the src and dest mac address)

stage == 1
00000000: 00 0F B7 11 27 2B 00 0F B7 11 27 2C 08 00 45 00 |....'+....',..E.
00000010: 00 2E 00 00 00 00 04 11 D5 B1 C0 A8 12 02 0E 01 |................
00000020: 00 63 10 00 10 01 00 1A 00 00 61 62 63 64 65 66 |.c........abcdef
00000030: 67 68 69 6A 6B 6C 6D 6E 6F 70 71 72 |  |  |  |  | ghijklmnopqr

stage == 2
00000000: 00 0F B7 11 27 2C 00 0F B7 11 27 2B 08 00 45 00 |....',....'+..E.
00000010: 00 2E 00 00 00 00 04 11 D5 B0 C0 A8 12 03 0E 01 |................
00000020: 00 63 10 00 10 01 00 1A 00 00 61 62 63 64 65 66 |.c........abcdef
00000030: 67 68 69 6A 6B 6C 6D 6E 6F 70 71 72 |  |  |  |  | ghijklmnopqr


diff --git a/examples/eventdev_pipeline_sw_pmd/main.c b/examples/eventdev_pipeline_sw_pmd/main.c
index c62cba2..a7aaf37 100644
--- a/examples/eventdev_pipeline_sw_pmd/main.c
+++ b/examples/eventdev_pipeline_sw_pmd/main.c
@@ -147,8 +147,9 @@ consumer(void)
        if (start_time == 0)
@@ -157,6 +158,7 @@ consumer(void)
        received += n;
        for (i = 0; i < n; i++) {
                uint8_t outport = packets[i].mbuf->port;
+               rte_pktmbuf_dump(stdout, packets[i].mbuf, 64);
                rte_eth_tx_buffer(outport, 0, fdata->tx_buf[outport],
                                packets[i].mbuf);

Either fix the mac swap properly or remove it.


> > > +
> > > +	if (!quiet) {
> > > +		printf("\nPort Workload distribution:\n");
> > > +		uint32_t i;
> > > +		uint64_t tot_pkts = 0;
> > > +		uint64_t pkts_per_wkr[RTE_MAX_LCORE] = {0};
> > > +		for (i = 0; i < num_workers; i++) {
> > > +			char statname[64];
> > > +			snprintf(statname, sizeof(statname), "port_%u_rx",
> > > +					worker_data[i].port_id);
> > > +			pkts_per_wkr[i] = rte_event_dev_xstats_by_name_get(
> > > +					dev_id, statname, NULL);
> > As discussed, Check the the given xstat supported on the PMD first.
> 
> Checking has now been implemented. It'd done by calling
> rte_event_dev_xstats_by_name_get()
> and seeing if the result is -ENOTSUP. However there is a bug in the function
> in that it is declared
> as a uint64_t, but then returns a -ENOTSUP, so I have to cast the -ENOTSUP
> as a uint64_t for
> comparison. This will need to be fixed when the function is patched.
> 
>                         retval = rte_event_dev_xstats_by_name_get(
>                                         dev_id, statname, NULL);
>                         if (retval != (uint64_t)-ENOTSUP) {
>                                 pkts_per_wkr[i] =  retval;
>                                 tot_pkts += pkts_per_wkr[i];
>                         }
> 
> 
> 
> > > +			tot_pkts += pkts_per_wkr[i];
> > > +		}
> > > +		for (i = 0; i < num_workers; i++) {
> > > +			float pc = pkts_per_wkr[i]  * 100 /
> > > +				((float)tot_pkts);

This will print NAN.

How about, move the specific xstat as static inline function.
port_stat(...)
{
		char statname[64];
		uint64_t retval;
		snprintf(statname, sizeof(statname),"port_%u_rx",      
				worker_data[i].port_id);                
		retval = rte_event_dev_xstats_by_name_get(              
				dev_id, statname, NULL); 
}
and add check in the beginning of the "if" condition.
ie.

	if (!cdata.quiet && port_stat(,,) != (uint64_t)-ENOTSUP) {
		printf("\nPort Workload distribution:\n");
		...
	}


> > > +			printf("worker %i :\t%.1f %% (%"PRIu64" pkts)\n",
> > > +					i, pc, pkts_per_wkr[i]);
> > > +		}
> > > +
> > > +	}
> > > +
> > > +	return 0;
> > > +}