From 3fa7aabf89b39410edc1f5e9057fcacd25c389b4 Mon Sep 17 00:00:00 2001 From: Piotr Lesnicki Date: Wed, 26 Jul 2017 17:10:24 +0200 Subject: [PATCH] fix srun latency, change default yield_when_idle=0 This changes the default to 0, to avoid yields during progress in srun. In mpirun, ompi_mpi_yield_when_idle is set to 1 if oversubscribed otherwise 0. But the default is 1 though, and it is used in srun. Now srun and mpirun have the same latency in non-oversubscribed cases. Signed-off-by: Piotr Lesnicki --- ompi/runtime/ompi_mpi_params.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/ompi/runtime/ompi_mpi_params.c b/ompi/runtime/ompi_mpi_params.c index 21fdaec1217..f8376db633d 100644 --- a/ompi/runtime/ompi_mpi_params.c +++ b/ompi/runtime/ompi_mpi_params.c @@ -62,7 +62,7 @@ bool ompi_mpi_keep_fqdn_hostnames = false; bool ompi_have_sparse_group_storage = OPAL_INT_TO_BOOL(OMPI_GROUP_SPARSE); bool ompi_use_sparse_group_storage = OPAL_INT_TO_BOOL(OMPI_GROUP_SPARSE); -bool ompi_mpi_yield_when_idle = true; +bool ompi_mpi_yield_when_idle = false; int ompi_mpi_event_tick_rate = -1; char *ompi_mpi_show_mca_params_string = NULL; bool ompi_mpi_have_sparse_group_storage = !!(OMPI_GROUP_SPARSE); @@ -107,7 +107,7 @@ int ompi_mpi_register_params(void) */ /* JMS: Need ORTE data here -- set this to 0 when exactly/under-subscribed, or 1 when oversubscribed */ - ompi_mpi_yield_when_idle = true; + ompi_mpi_yield_when_idle = false; (void) mca_base_var_register("ompi", "mpi", NULL, "yield_when_idle", "Yield the processor when waiting for MPI communication (for MPI processes, will default to 1 when oversubscribing nodes)", MCA_BASE_VAR_TYPE_BOOL, NULL, 0, 0,