Hi Ilia,
> -----Original Message-----
> From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of ilia.kura...@intel.com
> Sent: Monday, June 19, 2017 6:18 PM
> To: dev@dpdk.org
> Cc: Kurakin, Ilia <ilia.kura...@intel.com>
> Subject: [dpdk-dev] [PATCH] ether: add support for vtune task tracing
>
> From: Ilia Kurakin <ilia.kura...@intel.com>
>
> The patch adds tracing of loop iterations that yielded no packets in a DPDK
> application. It is using ITT task API:
> https://software.intel.com/en-us/node/544206
>
> We suppose the flow of using this tracing would assume the user has ITT lib
> and header on his machine and re-build DPDK with additional make parameters:
>
> make EXTRA_CFLAGS=-I<path to ittnotify.h>
> EXTRA_LDLIBS="-L<path to libittnotify.a> -littnotify"
There are few things that worry me with that patch:
1. We add new config variable and add extra dependency here.
Usually we try not to do that without really compelling reason.
2. We pollute rte_ethdev with the code that has nothing to do with
it major functionality.
That makes me wonder why this vtune data collection has to be done
inside rx_burst() function?
Why it can't be done on the application layer, i.e. straight after rx_burst()
is finished?
Something like:
n = rte_eth_rx_burst(port, queue, ....);
itt_rx_collect_data(port, queue, n, ....);
?
Or as alternative, user can install this vtune collection routine as
rx callback function.
Konstantin
>
> Signed-off-by: Ilia Kurakin <ilia.kura...@intel.com>
> ---
> config/common_base | 1 +
> lib/librte_ether/Makefile | 1 +
> lib/librte_ether/rte_eth_itt.h | 69
> ++++++++++++++++++++++++++++++++++++++++++
> lib/librte_ether/rte_ethdev.c | 7 +++++
> lib/librte_ether/rte_ethdev.h | 26 ++++++++++++++++
> 5 files changed, 104 insertions(+)
> create mode 100644 lib/librte_ether/rte_eth_itt.h
>
> diff --git a/config/common_base b/config/common_base
> index f6aafd1..60d8b63 100644
> --- a/config/common_base
> +++ b/config/common_base
> @@ -135,6 +135,7 @@ CONFIG_RTE_MAX_QUEUES_PER_PORT=1024
> CONFIG_RTE_LIBRTE_IEEE1588=n
> CONFIG_RTE_ETHDEV_QUEUE_STAT_CNTRS=16
> CONFIG_RTE_ETHDEV_RXTX_CALLBACKS=y
> +CONFIG_RTE_ETHDEV_TRACE_WASTED_RX_ITERATIONS=n
>
> #
> # Turn off Tx preparation stage
> diff --git a/lib/librte_ether/Makefile b/lib/librte_ether/Makefile
> index 93fdde1..c10153a 100644
> --- a/lib/librte_ether/Makefile
> +++ b/lib/librte_ether/Makefile
> @@ -56,5 +56,6 @@ SYMLINK-y-include += rte_eth_ctrl.h
> SYMLINK-y-include += rte_dev_info.h
> SYMLINK-y-include += rte_flow.h
> SYMLINK-y-include += rte_flow_driver.h
> +SYMLINK-${CONFIG_RTE_ETHDEV_TRACE_WASTED_RX_ITERATIONS}-include +=
> rte_eth_itt.h
>
> include $(RTE_SDK)/mk/rte.lib.mk
> diff --git a/lib/librte_ether/rte_eth_itt.h b/lib/librte_ether/rte_eth_itt.h
> new file mode 100644
> index 0000000..e7984fb
> --- /dev/null
> +++ b/lib/librte_ether/rte_eth_itt.h
> @@ -0,0 +1,69 @@
> +#ifndef _RTE_ETH_ITT_H_
> +#define _RTE_ETH_ITT_H_
> +
> +#include <ittnotify.h>
> +#include <rte_config.h>
> +
> +#define ITT_MAX_NAME_LEN (100)
> +
> +/**
> + * Auxiliary ITT structure belonging to port and using to:
> + * - track queue state to determine whether it is wasting loop iterations
> + * - begin or end ITT task using task domain and name
> + */
> +struct rte_eth_itt_aux_data {
> + /**
> + * ITT domains for each queue.
> + */
> + __itt_domain *wasted_iteration_itt_domains[RTE_MAX_QUEUES_PER_PORT];
> + /**
> + * ITT task names for each queue.
> + */
> + __itt_string_handle
> *wasted_iteration_itt_handles[RTE_MAX_QUEUES_PER_PORT];
> + /**
> + * Flags indicating the queues state. Possible values:
> + * 1 - queue is wasting iterations, 0 - otherwise.
> + */
> + uint8_t queue_is_wasting_iterations[RTE_MAX_QUEUES_PER_PORT];
> +};
> +
> +/**
> + * The pool of *rte_eth_itt_aux_data* structures.
> + */
> +struct rte_eth_itt_aux_data itt_aux_data[RTE_MAX_ETHPORTS];
> +
> +/**
> + * Initialization of rte_eth_itt_aux_data for a given port.
> + * This function must be invoked when ethernet device is being configured.
> + * Result will be stored in the global array *itt_aux_data*.
> + *
> + * @param port_id
> + * The port identifier of the Ethernet device.
> + * @param port_name
> + * The name of the Ethernet device.
> + * @param queue_num
> + * The number of queues on specified port.
> + */
> +static inline void
> +rte_eth_init_itt(uint8_t port_id, char *port_name, uint8_t queue_num) {
> + uint16_t q_id;
> + for (q_id = 0; q_id < queue_num; ++q_id) {
> + char domain_name[ITT_MAX_NAME_LEN];
> + snprintf(domain_name, sizeof(domain_name),
> + "RXBurst.WastedIterations.Port_%s.Queue_%d",
> + port_name, q_id);
> + itt_aux_data[port_id].wasted_iteration_itt_domains[q_id]
> + = __itt_domain_create(domain_name);
> +
> + char task_name[ITT_MAX_NAME_LEN];
> + snprintf(task_name, sizeof(task_name),
> + "port id: %d; queue id: %d",
> + port_id, q_id);
> + itt_aux_data[port_id].wasted_iteration_itt_handles[q_id]
> + = __itt_string_handle_create(task_name);
> +
> + itt_aux_data[port_id].queue_is_wasting_iterations[q_id] = 0;
> + }
> +}
> +
> +#endif
> diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
> index 81a45c0..9e5ac01 100644
> --- a/lib/librte_ether/rte_ethdev.c
> +++ b/lib/librte_ether/rte_ethdev.c
> @@ -818,6 +818,13 @@ rte_eth_dev_configure(uint8_t port_id, uint16_t nb_rx_q,
> uint16_t nb_tx_q,
> return diag;
> }
>
> +#ifdef RTE_ETHDEV_TRACE_WASTED_RX_ITERATIONS
> + /**
> + * See rte_eth_itt.h to find comments on code below.
> + */
> + rte_eth_init_itt(port_id, dev->data->name, nb_rx_q);
> +#endif
> +
> return 0;
> }
>
> diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h
> index f6e6c74..4ba90d2 100644
> --- a/lib/librte_ether/rte_ethdev.h
> +++ b/lib/librte_ether/rte_ethdev.h
> @@ -186,6 +186,10 @@ extern "C" {
> #include "rte_eth_ctrl.h"
> #include "rte_dev_info.h"
>
> +#ifdef RTE_ETHDEV_TRACE_WASTED_RX_ITERATIONS
> +#include "rte_eth_itt.h"
> +#endif
> +
> struct rte_mbuf;
>
> /**
> @@ -2710,6 +2714,28 @@ rte_eth_rx_burst(uint8_t port_id, uint16_t queue_id,
> int16_t nb_rx = (*dev->rx_pkt_burst)(dev->data->rx_queues[queue_id],
> rx_pkts, nb_pkts);
>
> +#ifdef RTE_ETHDEV_TRACE_WASTED_RX_ITERATIONS
> + /**
> + * See rte_eth_itt.h to find comments on code below.
> + */
> + if (unlikely(nb_rx == 0)) {
> + if
> (!itt_aux_data[port_id].queue_is_wasting_iterations[queue_id]) {
> + __itt_task_begin(
> +
> itt_aux_data[port_id].wasted_iteration_itt_domains[queue_id],
> + __itt_null, __itt_null,
> +
> itt_aux_data[port_id].wasted_iteration_itt_handles[queue_id]);
> +
> itt_aux_data[port_id].queue_is_wasting_iterations[queue_id] = 1;
> + }
> + }
> + else {
> + if
> (unlikely(itt_aux_data[port_id].queue_is_wasting_iterations[queue_id])) {
> + __itt_task_end(
> +
> itt_aux_data[port_id].wasted_iteration_itt_domains[queue_id]);
> +
> itt_aux_data[port_id].queue_is_wasting_iterations[queue_id] = 0;
> + }
> + }
> +#endif
> +
> #ifdef RTE_ETHDEV_RXTX_CALLBACKS
> struct rte_eth_rxtx_callback *cb = dev->post_rx_burst_cbs[queue_id];
>
> --
> 2.7.4
>
>
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