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openmpi/ompi/runtime/ompi_spc.h
Joseph Schuchart d11f625ed5 SPC: allow counters to be attached solely through MPI_T and reduce overhead
- only make MCA parameters available if SPC is enabled

- do not compile SPC code if SPC is disabled

- move includes into ompi_spc.c

- allow counters to be enabled through MPI_T without setting MCA parameter

- inline counter update calls that are likely in the critical path

- fix test to succeed even if encountering invalid pvars

- move timer_[start|stop] to header and move attachment info into ompi_spc_t

There is no need to store the name in the ompi_spc_t struct too, we can use that space
for the attachment info instead to avoid accessing another cache line.

- make timer/watermark flags a property of the spc description

This is meant to making adding counters easier in the future by
centralizing the necessary information. By storing a copy of these flags
in the ompi_spc_t structure (without adding to its size) reduces
cache pollution for timer/watermark events.

- allocate ompi_spc_t objects with cache-alignment

This prevents objects from spanning multiple cache lines and thus
ensures that only one cache line is loaded per update.

- fix handling of timer and timer conversion

- only call opal_timer_base_get_cycles if necesary to reduce overhead

- Remove use of OPAL_UNLIKELY to improve code generated by GCC

It appears that GCC makes less effort in optimizing the unlikely path
and generates bloated code.

- Allocate ompi_spc_events statically to reduce loads in critical path

- duplicate comm_world only when dumping is requested

Signed-off-by: Joseph Schuchart <schuchart@icl.utk.edu>
2020-11-12 21:17:56 +01:00

313 строки
9.3 KiB
C

/*
* Copyright (c) 2018-2020 The University of Tennessee and The University
* of Tennessee Research Foundation. All rights
* reserved.
* Copyright (c) 2018 Research Organization for Information Science
* and Technology (RIST). All rights reserved.
*
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#ifndef OMPI_SPC
#define OMPI_SPC
#include "ompi_config.h"
#include "opal/sys/atomic.h"
#include "opal/include/opal/prefetch.h"
#include "opal/mca/threads/thread_usage.h"
#include MCA_timer_IMPLEMENTATION_HEADER
/* INSTRUCTIONS FOR ADDING COUNTERS
* 1.) Add a new counter name in the ompi_spc_counters_t enum before
* OMPI_SPC_NUM_COUNTERS below.
* 2.) Add corresponding counter name and descriptions to the
* counter_names and counter_descriptions arrays in
* ompi_spc.c NOTE: The names and descriptions
* MUST be in the same array location as where you added the
* counter name in step 1.
* 3.) If this counter is based on a timer, add its enum name to
* the logic for timer-based counters in the ompi_spc_init
* function in ompi_spc.c
* 4.) Instrument the Open MPI code base where it makes sense for
* your counter to be modified using the SPC_RECORD macro.
* Note: If your counter is timer-based you should use the
* SPC_TIMER_START and SPC_TIMER_STOP macros to record
* the time in cycles to then be converted to microseconds later
* in the ompi_spc_get_count function when requested by MPI_T
*/
/* This enumeration serves as event ids for the various events */
typedef enum ompi_spc_counters {
OMPI_SPC_SEND,
OMPI_SPC_BSEND,
OMPI_SPC_RSEND,
OMPI_SPC_SSEND,
OMPI_SPC_RECV,
OMPI_SPC_MRECV,
OMPI_SPC_ISEND,
OMPI_SPC_IBSEND,
OMPI_SPC_IRSEND,
OMPI_SPC_ISSEND,
OMPI_SPC_IRECV,
OMPI_SPC_SENDRECV,
OMPI_SPC_SENDRECV_REPLACE,
OMPI_SPC_PUT,
OMPI_SPC_RPUT,
OMPI_SPC_GET,
OMPI_SPC_RGET,
OMPI_SPC_PROBE,
OMPI_SPC_IPROBE,
OMPI_SPC_BCAST,
OMPI_SPC_IBCAST,
OMPI_SPC_BCAST_INIT,
OMPI_SPC_REDUCE,
OMPI_SPC_REDUCE_SCATTER,
OMPI_SPC_REDUCE_SCATTER_BLOCK,
OMPI_SPC_IREDUCE,
OMPI_SPC_IREDUCE_SCATTER,
OMPI_SPC_IREDUCE_SCATTER_BLOCK,
OMPI_SPC_REDUCE_INIT,
OMPI_SPC_REDUCE_SCATTER_INIT,
OMPI_SPC_REDUCE_SCATTER_BLOCK_INIT,
OMPI_SPC_ALLREDUCE,
OMPI_SPC_IALLREDUCE,
OMPI_SPC_ALLREDUCE_INIT,
OMPI_SPC_SCAN,
OMPI_SPC_EXSCAN,
OMPI_SPC_ISCAN,
OMPI_SPC_IEXSCAN,
OMPI_SPC_SCAN_INIT,
OMPI_SPC_EXSCAN_INIT,
OMPI_SPC_SCATTER,
OMPI_SPC_SCATTERV,
OMPI_SPC_ISCATTER,
OMPI_SPC_ISCATTERV,
OMPI_SPC_SCATTER_INIT,
OMPI_SPC_SCATTERV_INIT,
OMPI_SPC_GATHER,
OMPI_SPC_GATHERV,
OMPI_SPC_IGATHER,
OMPI_SPC_IGATHERV,
OMPI_SPC_GATHER_INIT,
OMPI_SPC_GATHERV_INIT,
OMPI_SPC_ALLTOALL,
OMPI_SPC_ALLTOALLV,
OMPI_SPC_ALLTOALLW,
OMPI_SPC_IALLTOALL,
OMPI_SPC_IALLTOALLV,
OMPI_SPC_IALLTOALLW,
OMPI_SPC_ALLTOALL_INIT,
OMPI_SPC_ALLTOALLV_INIT,
OMPI_SPC_ALLTOALLW_INIT,
OMPI_SPC_NEIGHBOR_ALLTOALL,
OMPI_SPC_NEIGHBOR_ALLTOALLV,
OMPI_SPC_NEIGHBOR_ALLTOALLW,
OMPI_SPC_INEIGHBOR_ALLTOALL,
OMPI_SPC_INEIGHBOR_ALLTOALLV,
OMPI_SPC_INEIGHBOR_ALLTOALLW,
OMPI_SPC_NEIGHBOR_ALLTOALL_INIT,
OMPI_SPC_NEIGHBOR_ALLTOALLV_INIT,
OMPI_SPC_NEIGHBOR_ALLTOALLW_INIT,
OMPI_SPC_ALLGATHER,
OMPI_SPC_ALLGATHERV,
OMPI_SPC_IALLGATHER,
OMPI_SPC_IALLGATHERV,
OMPI_SPC_ALLGATHER_INIT,
OMPI_SPC_ALLGATHERV_INIT,
OMPI_SPC_NEIGHBOR_ALLGATHER,
OMPI_SPC_NEIGHBOR_ALLGATHERV,
OMPI_SPC_INEIGHBOR_ALLGATHER,
OMPI_SPC_INEIGHBOR_ALLGATHERV,
OMPI_SPC_NEIGHBOR_ALLGATHER_INIT,
OMPI_SPC_NEIGHBOR_ALLGATHERV_INIT,
OMPI_SPC_TEST,
OMPI_SPC_TESTALL,
OMPI_SPC_TESTANY,
OMPI_SPC_TESTSOME,
OMPI_SPC_WAIT,
OMPI_SPC_WAITALL,
OMPI_SPC_WAITANY,
OMPI_SPC_WAITSOME,
OMPI_SPC_BARRIER,
OMPI_SPC_IBARRIER,
OMPI_SPC_BARRIER_INIT,
OMPI_SPC_WTIME,
OMPI_SPC_CANCEL,
OMPI_SPC_BYTES_RECEIVED_USER,
OMPI_SPC_BYTES_RECEIVED_MPI,
OMPI_SPC_BYTES_SENT_USER,
OMPI_SPC_BYTES_SENT_MPI,
OMPI_SPC_BYTES_PUT,
OMPI_SPC_BYTES_GET,
OMPI_SPC_UNEXPECTED,
OMPI_SPC_OUT_OF_SEQUENCE,
OMPI_SPC_MATCH_TIME,
OMPI_SPC_UNEXPECTED_IN_QUEUE,
OMPI_SPC_OOS_IN_QUEUE,
OMPI_SPC_MAX_UNEXPECTED_IN_QUEUE,
OMPI_SPC_MAX_OOS_IN_QUEUE,
OMPI_SPC_NUM_COUNTERS /* This serves as the number of counters. It must be last. */
} ompi_spc_counters_t;
/* There is currently no support for atomics on long long values so we will default to
* size_t for now until support for such atomics is implemented.
*/
typedef long long ompi_spc_value_t;
/* A structure for storing the event data */
typedef struct ompi_spc_s{
opal_atomic_int64_t value;
opal_atomic_int32_t num_attached;
bool is_high_watermark;
bool is_timer_event;
} ompi_spc_t;
/* Definitions for using the SPC utility functions throughout the codebase.
* If SPC_ENABLE is not 1, the macros become no-ops.
*/
#if SPC_ENABLE == 1
/* OMPI SPC utility functions */
void ompi_spc_init(void);
void ompi_spc_fini(void);
void ompi_spc_cycles_to_usecs(opal_timer_t *cycles);
/* An array of event structures to store the event data value, attachments, flags)
* The memory is statically allocated to reduce the number of loads required.
*/
OPAL_DECLSPEC extern
ompi_spc_t ompi_spc_events[OMPI_SPC_NUM_COUNTERS] __opal_attribute_aligned__(sizeof(ompi_spc_t));
#define SPC_INIT() \
ompi_spc_init()
#define SPC_FINI() \
ompi_spc_fini()
#define SPC_RECORD(event_id, value) \
ompi_spc_record(event_id, value)
#define SPC_TIMER_START(event_id, usec) \
ompi_spc_timer_start(event_id, usec)
#define SPC_TIMER_STOP(event_id, usec) \
ompi_spc_timer_stop(event_id, usec)
#define SPC_USER_OR_MPI(tag, value, enum_if_user, enum_if_mpi) \
ompi_spc_user_or_mpi(tag, value, enum_if_user, enum_if_mpi)
#define SPC_CYCLES_TO_USECS(cycles) \
ompi_spc_cycles_to_usecs(cycles)
#define SPC_UPDATE_WATERMARK(watermark_enum, value_enum) \
ompi_spc_update_watermark(watermark_enum, value_enum)
/* Records an update to a counter using an atomic add operation. */
static inline
void ompi_spc_record(unsigned int event_id, ompi_spc_value_t value)
{
/* Denoted unlikely because counters will often be turned off. */
if( ompi_spc_events[event_id].num_attached > 0 ) {
OPAL_THREAD_ADD_FETCH64(&(ompi_spc_events[event_id].value), value);
}
}
/* Checks a tag, and records the user version of the counter if it's greater
* than or equal to 0 and records the mpi version of the counter otherwise.
*/
static inline
void ompi_spc_user_or_mpi(int tag, ompi_spc_value_t value, unsigned int user_enum, unsigned int mpi_enum)
{
ompi_spc_record( (tag >= 0 ? user_enum : mpi_enum), value);
}
/* Checks whether the counter denoted by value_enum exceeds the current value of the
* counter denoted by watermark_enum, and if so sets the watermark_enum counter to the
* value of the value_enum counter.
*/
static inline
void ompi_spc_update_watermark(unsigned int watermark_enum, unsigned int value_enum)
{
ompi_spc_t *watermark_event = &ompi_spc_events[watermark_enum];
ompi_spc_t *value_event = &ompi_spc_events[value_enum];
/* Denoted unlikely because counters will often be turned off. */
if( watermark_event->num_attached &&
value_event->num_attached ) {
int64_t watermark = watermark_event->value;
int64_t value = watermark_event->value;
/* Try to atomically replace the watermark while the value is larger
* (i.e, while no thread has replaced it with a larger value, including this thread) */
while (value > watermark &&
!OPAL_THREAD_COMPARE_EXCHANGE_STRONG_64(&watermark_event->value,
&watermark, value))
{ }
}
}
/*
* Starts cycle-precision timer and stores the start value in the 'cycles' argument.
* The value is always stored in 'cycles' to avoid race conditions with other threads
* activating a previously inactive timer counter in between start and stop.
*/
static inline
void ompi_spc_timer_start(unsigned int event_id, opal_timer_t *cycles)
{
(void)event_id; /* unused */
*cycles = 0;
if( (ompi_spc_events[event_id].num_attached > 0) ) {
*cycles = opal_timer_base_get_cycles();
}
}
/* Stops a cycle-precision timer and calculates the total elapsed time
* based on the starting time in 'cycles' and stores the result in the
* 'cycles' argument.
*/
static inline
void ompi_spc_timer_stop(unsigned int event_id, opal_timer_t *cycles)
{
if( ompi_spc_events[event_id].num_attached > 0 && *cycles > 0 ) {
*cycles = opal_timer_base_get_cycles() - *cycles;
OPAL_THREAD_ADD_FETCH64(&ompi_spc_events[event_id].value, *cycles);
}
}
#else /* SPCs are not enabled */
#define SPC_INIT() \
((void)0)
#define SPC_FINI() \
((void)0)
#define SPC_RECORD(event_id, value) \
((void)0)
#define SPC_TIMER_START(event_id, usec) \
((void)0)
#define SPC_TIMER_STOP(event_id, usec) \
((void)0)
#define SPC_USER_OR_MPI(tag, value, enum_if_user, enum_if_mpi) \
((void)0)
#define SPC_CYCLES_TO_USECS(cycles) \
((void)0)
#define SPC_UPDATE_WATERMARK(watermark_enum, value_enum) \
((void)0)
#endif
#endif