[dcmf] [PATCH] This test will repeatedly call the low-level critical-section functions for performance testing.

[Kazutomo Yoshii]

I noticed that there is a code fragment
that lwarx/stwarx is used for CriticalSection().
( sys/messaging/sysdep/prod/BGP/MutexImpl.h )
it's not used now.  Is this a plan for future release?
or just test code?

Do you have any performance comparison
between lockbox device and lwarx/stwarx instruction?

- kaz

> This is helpful when trying to understand performance degradations in MPI_THREAD_MULTIPLE.
> 
> Signed-off-by: Joe Ratterman <jratt at us.ibm.com>
> ---
>  sys/tests/perf/Makefile.in            |    2 +-
>  sys/tests/perf/dcmf/CS.c              |   64 +++++++++++++++++++++++++++++++++
>  sys/tests/perf/{ => dcmf}/Makefile.in |    4 +-
>  3 files changed, 67 insertions(+), 3 deletions(-)
>  create mode 100644 sys/tests/perf/dcmf/CS.c
>  copy sys/tests/perf/{ => dcmf}/Makefile.in (96%)
> 
> diff --git a/sys/tests/perf/Makefile.in b/sys/tests/perf/Makefile.in
> index 22a7ac7..4266989 100644
> --- a/sys/tests/perf/Makefile.in
> +++ b/sys/tests/perf/Makefile.in
> @@ -12,6 +12,6 @@
>  # end_generated_IBM_copyright_prolog                               #
>  
>  VPATH		= @abs_srcdir@
> -SUBDIRS		= mpi spi mpid
> +SUBDIRS		= mpi spi mpid dcmf
>  TESTS		= 
>  include @abs_top_builddir@/Make.rules
> diff --git a/sys/tests/perf/dcmf/CS.c b/sys/tests/perf/dcmf/CS.c
> new file mode 100644
> index 0000000..080f5df
> --- /dev/null
> +++ b/sys/tests/perf/dcmf/CS.c
> @@ -0,0 +1,64 @@
> +/* begin_generated_IBM_copyright_prolog                             */
> +/*                                                                  */
> +/* ---------------------------------------------------------------- */
> +/* (C)Copyright IBM Corp.  2007, 2008                               */
> +/* IBM CPL License                                                  */
> +/* ---------------------------------------------------------------- */
> +/*                                                                  */
> +/* end_generated_IBM_copyright_prolog                               */
> +/**
> + * \file perf/dcmf/CS.c
> + * \brief Test the performance of the low-level critical-section functions
> + */
> +
> +
> +#include <tests.h>
> +#define NUM 10000
> +DCMF_Configure_t config;
> +
> +
> +double time_CS(uint32_t x)
> +{
> +  uint64_t start, stop;
> +  uint32_t i;
> +
> +  start = DCMF_Timebase();
> +  for (i=0; i<x; ++i) {
> +    DCMF_CriticalSection_enter(0);
> +    DCMF_CriticalSection_exit(0);
> +  }
> +  stop  = DCMF_Timebase();
> +
> +  return (double)(stop-start)/(double)x;
> +}
> +
> +
> +#define time_run(c) time_run_long(c, #c)
> +void time_run_long(DCMF_Thread thread_level, char* thread_string)
> +{
> +  double time;
> +  DCMF_Result rc;
> +
> +  config.thread_level = thread_level;
> +  rc = DCMF_Messager_configure (&config, &config);
> +  assert(rc == DCMF_SUCCESS);
> +  assert(config.thread_level == thread_level);
> +  time = time_CS(NUM);
> +  printf("%s: Called Enter/Exit %u times at %g cycles each.\n", thread_string, NUM, time);
> +}
> +
> +
> +int main()
> +{
> +  config.interrupts = DCMF_INTERRUPTS_OFF;
> +
> +  MPI_INIT;
> +
> +  time_run(DCMF_THREAD_SINGLE);
> +  time_run(DCMF_THREAD_FUNNELED);
> +  time_run(DCMF_THREAD_SERIALIZED);
> +  time_run(DCMF_THREAD_MULTIPLE);
> +
> +  MPI_FINALIZE;
> +  return (0);
> +}
> diff --git a/sys/tests/perf/Makefile.in b/sys/tests/perf/dcmf/Makefile.in
> similarity index 96%
> copy from sys/tests/perf/Makefile.in
> copy to sys/tests/perf/dcmf/Makefile.in
> index 22a7ac7..4c474b6 100644
> --- a/sys/tests/perf/Makefile.in
> +++ b/sys/tests/perf/dcmf/Makefile.in
> @@ -12,6 +12,6 @@
>  # end_generated_IBM_copyright_prolog                               #
>  
>  VPATH		= @abs_srcdir@
> -SUBDIRS		= mpi spi mpid
> -TESTS		= 
> +SUBDIRS		= 
> +TESTS		= CS.c
>  include @abs_top_builddir@/Make.rules