RE: [PATCH 1/1] eal: add tracepoints to track lcores and services

["Van Haaren, Harry" <harry.van.haaren@intel.com>]

> -----Original Message-----
> From: Arnaud Fiorini <arnaud.fiorini@polymtl.ca>
> Sent: Monday, April 24, 2023 4:24 PM
> To: Thomas Monjalon <thomas@monjalon.net>; Jerin Jacob <jerinj@marvell.com>;
> Sunil Kumar Kori <skori@marvell.com>; Van Haaren, Harry
> <harry.van.haaren@intel.com>
> Cc: dev@dpdk.org; Arnaud Fiorini <arnaud.fiorini@polymtl.ca>
> Subject: [PATCH 1/1] eal: add tracepoints to track lcores and services
> 
> The tracepoints added are used to track lcore role and status,
> as well as service mapping and service runstates. These
> tracepoints are then used in analyses in Trace Compass.
> 
> Signed-off-by: Arnaud Fiorini <arnaud.fiorini@polymtl.ca>

I've had a look at these changes, and don't have any big objections;
When disabled, the tracepoints add no measurable overhead here, but
When enabled they cause a ~+50% cycle-cost (eg from ~100 to 150 cycles).
Running the "service_perf_autotest" prints cycle-costs, so this is easy to check.

Please add documentation on enabling the traces; today it is hard to identify/find
an example of enabling tracing on service-cores. Suggest to add it to:
1) the commit message, how to enable service cores traces only
2) add a section in the service-cores documentation, to enable service-cores only, and link to tracing documentation page for more info.

+CC Mattias and Honnappa who have expressed specific interest in service-cores
Performance in the past, any concerns/input Mattias/Honnappa?

@Arnaud, assuming no concerns from wider DPDK community, I'm happy to Ack a v2 with docs added.


> ---
>  .mailmap                                 |  1 +
>  lib/eal/common/eal_common_thread.c       |  4 ++
>  lib/eal/common/eal_common_trace_points.c | 21 +++++++++
>  lib/eal/common/rte_service.c             | 18 ++++++-
>  lib/eal/include/eal_trace_internal.h     | 60 ++++++++++++++++++++++++
>  5 files changed, 103 insertions(+), 1 deletion(-)
> 
> diff --git a/.mailmap b/.mailmap
> index dc30369117..2a0b132572 100644
> --- a/.mailmap
> +++ b/.mailmap
> @@ -120,6 +120,7 @@ Archana Muniganti <marchana@marvell.com>
> <muniganti.archana@caviumnetworks.com>
>  Archit Pandey <architpandeynitk@gmail.com>
>  Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
>  Arkadiusz Kusztal <arkadiuszx.kusztal@intel.com>
> +Arnaud Fiorini <arnaud.fiorini@polymtl.ca>
>  Arnon Warshavsky <arnon@qwilt.com>
>  Arshdeep Kaur <arshdeep.kaur@intel.com>
>  Artem V. Andreev <artem.andreev@oktetlabs.ru>
> diff --git a/lib/eal/common/eal_common_thread.c
> b/lib/eal/common/eal_common_thread.c
> index 079a385630..25dbdd68e3 100644
> --- a/lib/eal/common/eal_common_thread.c
> +++ b/lib/eal/common/eal_common_thread.c
> @@ -205,6 +205,8 @@ eal_thread_loop(void *arg)
>  				__ATOMIC_ACQUIRE)) == NULL)
>  			rte_pause();
> 
> +		rte_eal_trace_thread_lcore_running(lcore_id, f);
> +
>  		/* call the function and store the return value */
>  		fct_arg = lcore_config[lcore_id].arg;
>  		ret = f(fct_arg);
> @@ -219,6 +221,8 @@ eal_thread_loop(void *arg)
>  		 */
>  		__atomic_store_n(&lcore_config[lcore_id].state, WAIT,
>  			__ATOMIC_RELEASE);
> +
> +		rte_eal_trace_thread_lcore_stopped(lcore_id);
>  	}
> 
>  	/* never reached */
> diff --git a/lib/eal/common/eal_common_trace_points.c
> b/lib/eal/common/eal_common_trace_points.c
> index 3f5bf5c55c..0f1240ea3a 100644
> --- a/lib/eal/common/eal_common_trace_points.c
> +++ b/lib/eal/common/eal_common_trace_points.c
> @@ -70,6 +70,27 @@
> RTE_TRACE_POINT_REGISTER(rte_eal_trace_thread_remote_launch,
>  	lib.eal.thread.remote.launch)
>  RTE_TRACE_POINT_REGISTER(rte_eal_trace_thread_lcore_ready,
>  	lib.eal.thread.lcore.ready)
> +RTE_TRACE_POINT_REGISTER(rte_eal_trace_thread_lcore_running,
> +	lib.eal.thread.lcore.running)
> +RTE_TRACE_POINT_REGISTER(rte_eal_trace_thread_lcore_stopped,
> +	lib.eal.thread.lcore.stopped)
> +
> +RTE_TRACE_POINT_REGISTER(rte_eal_trace_service_map_lcore,
> +	lib.eal.service.map.lcore)
> +RTE_TRACE_POINT_REGISTER(rte_eal_trace_service_lcore_state_change,
> +	lib.eal.service.lcore.state.change)
> +RTE_TRACE_POINT_REGISTER(rte_eal_trace_service_lcore_start,
> +	lib.eal.service.lcore.start)
> +RTE_TRACE_POINT_REGISTER(rte_eal_trace_service_lcore_stop,
> +	lib.eal.service.lcore.stop)
> +RTE_TRACE_POINT_REGISTER(rte_eal_trace_service_run_begin,
> +	lib.eal.service.run.begin)
> +RTE_TRACE_POINT_REGISTER(rte_eal_trace_service_runstate_set,
> +	lib.eal.service.run.state.set)
> +RTE_TRACE_POINT_REGISTER(rte_eal_trace_service_run_end,
> +	lib.eal.service.run.end)
> +RTE_TRACE_POINT_REGISTER(rte_eal_trace_service_component_register,
> +	lib.eal.service.component.register)
> 
>  RTE_TRACE_POINT_REGISTER(rte_eal_trace_intr_callback_register,
>  	lib.eal.intr.register)
> diff --git a/lib/eal/common/rte_service.c b/lib/eal/common/rte_service.c
> index 42ca1d001d..5daec007aa 100644
> --- a/lib/eal/common/rte_service.c
> +++ b/lib/eal/common/rte_service.c
> @@ -9,6 +9,7 @@
>  #include <rte_service.h>
>  #include <rte_service_component.h>
> 
> +#include <eal_trace_internal.h>
>  #include <rte_lcore.h>
>  #include <rte_branch_prediction.h>
>  #include <rte_common.h>
> @@ -16,6 +17,7 @@
>  #include <rte_atomic.h>
>  #include <rte_malloc.h>
>  #include <rte_spinlock.h>
> +#include <rte_trace_point.h>
> 
>  #include "eal_private.h"
> 
> @@ -276,6 +278,8 @@ rte_service_component_register(const struct
> rte_service_spec *spec,
>  	if (id_ptr)
>  		*id_ptr = free_slot;
> 
> +	rte_eal_trace_service_component_register(free_slot, spec->name);
> +
>  	return 0;
>  }
> 
> @@ -336,6 +340,7 @@ rte_service_runstate_set(uint32_t id, uint32_t runstate)
>  		__atomic_store_n(&s->app_runstate, RUNSTATE_STOPPED,
>  			__ATOMIC_RELEASE);
> 
> +	rte_eal_trace_service_runstate_set(id, runstate);
>  	return 0;
>  }
> 
> @@ -427,11 +432,15 @@ service_run(uint32_t i, struct core_state *cs, uint64_t
> service_mask,
>  		if (!rte_spinlock_trylock(&s->execute_lock))
>  			return -EBUSY;
> 
> +		rte_eal_trace_service_run_begin(i, rte_lcore_id());
>  		service_runner_do_callback(s, cs, i);
>  		rte_spinlock_unlock(&s->execute_lock);
> -	} else
> +	} else {
> +		rte_eal_trace_service_run_begin(i, rte_lcore_id());
>  		service_runner_do_callback(s, cs, i);
> +	}
> 
> +	rte_eal_trace_service_run_end(i, rte_lcore_id());
>  	return 0;
>  }
> 
> @@ -658,6 +667,7 @@ int32_t
>  rte_service_map_lcore_set(uint32_t id, uint32_t lcore, uint32_t enabled)
>  {
>  	uint32_t on = enabled > 0;
> +	rte_eal_trace_service_map_lcore(id, lcore, enabled);
>  	return service_update(id, lcore, &on, 0);
>  }
> 
> @@ -683,6 +693,8 @@ set_lcore_state(uint32_t lcore, int32_t state)
> 
>  	/* update per-lcore optimized state tracking */
>  	lcore_states[lcore].is_service_core = (state == ROLE_SERVICE);
> +
> +	rte_eal_trace_service_lcore_state_change(lcore, state);
>  }
> 
>  int32_t
> @@ -780,6 +792,8 @@ rte_service_lcore_start(uint32_t lcore)
>  	 */
>  	__atomic_store_n(&cs->runstate, RUNSTATE_RUNNING,
> __ATOMIC_RELEASE);
> 
> +	rte_eal_trace_service_lcore_start(lcore);
> +
>  	int ret = rte_eal_remote_launch(service_runner_func, 0, lcore);
>  	/* returns -EBUSY if the core is already launched, 0 on success */
>  	return ret;
> @@ -824,6 +838,8 @@ rte_service_lcore_stop(uint32_t lcore)
>  	__atomic_store_n(&lcore_states[lcore].runstate, RUNSTATE_STOPPED,
>  		__ATOMIC_RELEASE);
> 
> +	rte_eal_trace_service_lcore_stop(lcore);
> +
>  	return 0;
>  }
> 
> diff --git a/lib/eal/include/eal_trace_internal.h
> b/lib/eal/include/eal_trace_internal.h
> index 57d6de2535..9a37a08567 100644
> --- a/lib/eal/include/eal_trace_internal.h
> +++ b/lib/eal/include/eal_trace_internal.h
> @@ -174,6 +174,66 @@ RTE_TRACE_POINT(
>  	rte_trace_point_emit_u32(lcore_id);
>  	rte_trace_point_emit_string(cpuset);
>  )
> +RTE_TRACE_POINT_FP(
> +	rte_eal_trace_thread_lcore_running,
> +	RTE_TRACE_POINT_ARGS(unsigned int lcore_id, void *f),
> +	rte_trace_point_emit_u32(lcore_id);
> +	rte_trace_point_emit_ptr(f);
> +)
> +RTE_TRACE_POINT_FP(
> +	rte_eal_trace_thread_lcore_stopped,
> +	RTE_TRACE_POINT_ARGS(unsigned int lcore_id),
> +	rte_trace_point_emit_u32(lcore_id);
> +)
> +
> +/* Service */
> +RTE_TRACE_POINT(
> +	rte_eal_trace_service_map_lcore,
> +	RTE_TRACE_POINT_ARGS(unsigned int id, unsigned int lcore_id, unsigned int
> enabled),
> +	rte_trace_point_emit_u32(id);
> +	rte_trace_point_emit_u32(lcore_id);
> +	rte_trace_point_emit_u32(enabled);
> +)
> +RTE_TRACE_POINT(
> +	rte_eal_trace_service_lcore_state_change,
> +	RTE_TRACE_POINT_ARGS(unsigned int lcore_id, int lcore_state),
> +	rte_trace_point_emit_u32(lcore_id);
> +	rte_trace_point_emit_i32(lcore_state);
> +)
> +RTE_TRACE_POINT(
> +	rte_eal_trace_service_lcore_start,
> +	RTE_TRACE_POINT_ARGS(unsigned int lcore_id),
> +	rte_trace_point_emit_u32(lcore_id);
> +)
> +RTE_TRACE_POINT(
> +	rte_eal_trace_service_lcore_stop,
> +	RTE_TRACE_POINT_ARGS(unsigned int lcore_id),
> +	rte_trace_point_emit_u32(lcore_id);
> +)
> +RTE_TRACE_POINT_FP(
> +	rte_eal_trace_service_run_begin,
> +	RTE_TRACE_POINT_ARGS(unsigned int id, unsigned int lcore_id),
> +	rte_trace_point_emit_u32(id);
> +	rte_trace_point_emit_u32(lcore_id);
> +)
> +RTE_TRACE_POINT(
> +	rte_eal_trace_service_runstate_set,
> +	RTE_TRACE_POINT_ARGS(unsigned int id, unsigned int run_state),
> +	rte_trace_point_emit_u32(id);
> +	rte_trace_point_emit_u32(run_state);
> +)
> +RTE_TRACE_POINT(
> +	rte_eal_trace_service_run_end,
> +	RTE_TRACE_POINT_ARGS(unsigned int id, unsigned int lcore_id),
> +	rte_trace_point_emit_u32(id);
> +	rte_trace_point_emit_u32(lcore_id);
> +)
> +RTE_TRACE_POINT(
> +	rte_eal_trace_service_component_register,
> +	RTE_TRACE_POINT_ARGS(int id, const char *service_name),
> +	rte_trace_point_emit_i32(id);
> +	rte_trace_point_emit_string(service_name);
> +)
> 
>  #ifdef __cplusplus
>  }
> --
> 2.25.1