Only add a barrier to 8 collectives. The other ones don't seem to need it

diff --git a/ChangeLog b/ChangeLog
index 7863f28..e782fb0 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -5,8 +5,8 @@ S4U:
    Comm::set_payload_size() to change the size of the simulated data.
 
 MPI:
- - New option smpi/barrier-collectives to add a barrier in all
-   collectives to detect dangerous code that /may/ work on some implems.
+ - New option smpi/barrier-collectives to add a barrier to some collectives
+   to detect dangerous code that /may/ work on some MPI implems.
 
 Models:
  - WiFi: the total capacity of a link depends on the amout of flows on that link.

diff --git a/docs/source/Configuring_SimGrid.rst b/docs/source/Configuring_SimGrid.rst
index f5af4a0..6ed80fd 100644 (file)
--- a/docs/source/Configuring_SimGrid.rst
+++ b/docs/source/Configuring_SimGrid.rst
@@ -1376,13 +1376,13 @@ Add a barrier in all collectives
 
 **Option** ``smpi/barrier-collectives`` **default:** off
 
-This option adds a simple barrier in all collectives operation to catch dangerous
-code that may or may not work depending on the MPI implementation. It is disabled
-by default, and activated by the `-analyze` flag of smpirun.
+This option adds a simple barrier in some collective operations to catch dangerous
+code that may or may not work depending on the MPI implementation: Bcast, Exscan,
+Gather, Gatherv, Scan, Scatter, Scatterv and Reduce.
 
 For example, the following code works with OpenMPI while it deadlocks in MPICH and
-Intel MPI. It seems to mean that OpenMPI has a "fire and forget" implementation for
-Broadcast.
+Intel MPI. Broadcast seem to be "fire and forget" in OpenMPI while other
+implementations expect to receive a message.
 
 .. code-block:: C
 
@@ -1394,6 +1394,9 @@ Broadcast.
     MPI_Bcast(buf1, buff_size, MPI_CHAR, 0, newcom);
   }
 
+The barrier is only simulated and does not involve any additional message (it is a S4U barrier).
+This option is disabled by default, and activated by the `-analyze` flag of smpirun.
+
 .. _cfg=smpi/barrier-finalization:
 
 Add a barrier in MPI_Finalize

diff --git a/src/smpi/bindings/smpi_pmpi_coll.cpp b/src/smpi/bindings/smpi_pmpi_coll.cpp
index c626857..1804c73 100644 (file)
--- a/src/smpi/bindings/smpi_pmpi_coll.cpp
+++ b/src/smpi/bindings/smpi_pmpi_coll.cpp
@@ -76,7 +76,8 @@ int PMPI_Ibcast(void* buf, int count, MPI_Datatype datatype, int root, MPI_Comm
                      new simgrid::instr::CollTIData(request == MPI_REQUEST_IGNORED ? "bcast" : "ibcast", root, -1.0,
                                                     count, 0,
                                                     simgrid::smpi::Datatype::encode(datatype), ""));
-  if (simgrid::config::get_value<bool>("smpi/barrier-collectives"))
+  if (simgrid::config::get_value<bool>("smpi/barrier-collectives") &&
+      request == MPI_REQUEST_IGNORED) // No barrier in Ibcast
     smpi_deployment_startup_barrier(smpi_process()->get_instance_id());
 
   if (comm->size() > 1) {
@@ -138,7 +139,8 @@ int PMPI_Igather(const void* sendbuf, int sendcount, MPI_Datatype sendtype, void
 
   const SmpiBenchGuard suspend_bench;
 
-  if (simgrid::config::get_value<bool>("smpi/barrier-collectives"))
+  if (simgrid::config::get_value<bool>("smpi/barrier-collectives") &&
+      request == MPI_REQUEST_IGNORED) // no barrier in Igather
     smpi_deployment_startup_barrier(smpi_process()->get_instance_id());
 
   aid_t pid = simgrid::s4u::this_actor::get_pid();
@@ -197,7 +199,8 @@ int PMPI_Igatherv(const void* sendbuf, int sendcount, MPI_Datatype sendtype, voi
 
   const SmpiBenchGuard suspend_bench;
 
-  if (simgrid::config::get_value<bool>("smpi/barrier-collectives"))
+  if (simgrid::config::get_value<bool>("smpi/barrier-collectives") &&
+      request == MPI_REQUEST_IGNORED) // no barrier in Igatherv
     smpi_deployment_startup_barrier(smpi_process()->get_instance_id());
 
   const void* real_sendbuf   = sendbuf;
@@ -270,9 +273,6 @@ int PMPI_Iallgather(const void* sendbuf, int sendcount, MPI_Datatype sendtype, v
 
   const SmpiBenchGuard suspend_bench;
 
-  if (simgrid::config::get_value<bool>("smpi/barrier-collectives"))
-    smpi_deployment_startup_barrier(smpi_process()->get_instance_id());
-
   aid_t pid = simgrid::s4u::this_actor::get_pid();
 
   TRACE_smpi_comm_in(pid, request == MPI_REQUEST_IGNORED ? "PMPI_Allgather" : "PMPI_Iallggather",
@@ -320,9 +320,6 @@ int PMPI_Iallgatherv(const void* sendbuf, int sendcount, MPI_Datatype sendtype,
 
   const SmpiBenchGuard suspend_bench;
 
-  if (simgrid::config::get_value<bool>("smpi/barrier-collectives"))
-    smpi_deployment_startup_barrier(smpi_process()->get_instance_id());
-
   if (sendbuf == MPI_IN_PLACE) {
     sendbuf   = static_cast<char*>(recvbuf) + recvtype->get_extent() * displs[comm->rank()];
     sendcount = recvcounts[comm->rank()];
@@ -391,7 +388,8 @@ int PMPI_Iscatter(const void* sendbuf, int sendcount, MPI_Datatype sendtype, voi
 
   const SmpiBenchGuard suspend_bench;
 
-  if (simgrid::config::get_value<bool>("smpi/barrier-collectives"))
+  if (simgrid::config::get_value<bool>("smpi/barrier-collectives") &&
+      request == MPI_REQUEST_IGNORED) // no barrier in Iscatter
     smpi_deployment_startup_barrier(smpi_process()->get_instance_id());
 
   aid_t pid = simgrid::s4u::this_actor::get_pid();
@@ -450,7 +448,8 @@ int PMPI_Iscatterv(const void* sendbuf, const int* sendcounts, const int* displs
 
   const SmpiBenchGuard suspend_bench;
 
-  if (simgrid::config::get_value<bool>("smpi/barrier-collectives"))
+  if (simgrid::config::get_value<bool>("smpi/barrier-collectives") &&
+      request == MPI_REQUEST_IGNORED) // no barrier in Iscatterv
     smpi_deployment_startup_barrier(smpi_process()->get_instance_id());
 
   aid_t pid        = simgrid::s4u::this_actor::get_pid();
@@ -504,7 +503,8 @@ int PMPI_Ireduce(const void *sendbuf, void *recvbuf, int count, MPI_Datatype dat
 
   const SmpiBenchGuard suspend_bench;
 
-  if (simgrid::config::get_value<bool>("smpi/barrier-collectives"))
+  if (simgrid::config::get_value<bool>("smpi/barrier-collectives") &&
+      request == MPI_REQUEST_IGNORED) // no barrier in Ireduce
     smpi_deployment_startup_barrier(smpi_process()->get_instance_id());
 
   aid_t pid = simgrid::s4u::this_actor::get_pid();
@@ -560,9 +560,6 @@ int PMPI_Iallreduce(const void *sendbuf, void *recvbuf, int count, MPI_Datatype
 
   const SmpiBenchGuard suspend_bench;
 
-  if (simgrid::config::get_value<bool>("smpi/barrier-collectives"))
-    smpi_deployment_startup_barrier(smpi_process()->get_instance_id());
-
   std::vector<unsigned char> tmp_sendbuf;
   const void* real_sendbuf = smpi_get_in_place_buf(sendbuf, recvbuf, tmp_sendbuf, count, datatype);
 
@@ -603,7 +600,8 @@ int PMPI_Iscan(const void *sendbuf, void *recvbuf, int count, MPI_Datatype datat
 
   const SmpiBenchGuard suspend_bench;
 
-  if (simgrid::config::get_value<bool>("smpi/barrier-collectives"))
+  if (simgrid::config::get_value<bool>("smpi/barrier-collectives") &&
+      request == MPI_REQUEST_IGNORED) // no barrier in Iscan
     smpi_deployment_startup_barrier(smpi_process()->get_instance_id());
 
   aid_t pid = simgrid::s4u::this_actor::get_pid();
@@ -644,7 +642,8 @@ int PMPI_Iexscan(const void *sendbuf, void *recvbuf, int count, MPI_Datatype dat
 
   const SmpiBenchGuard suspend_bench;
 
-  if (simgrid::config::get_value<bool>("smpi/barrier-collectives"))
+  if (simgrid::config::get_value<bool>("smpi/barrier-collectives") &&
+      request == MPI_REQUEST_IGNORED) // no barrier in Iexscan
     smpi_deployment_startup_barrier(smpi_process()->get_instance_id());
 
   aid_t pid = simgrid::s4u::this_actor::get_pid();
@@ -691,9 +690,6 @@ int PMPI_Ireduce_scatter(const void *sendbuf, void *recvbuf, const int *recvcoun
 
   const SmpiBenchGuard suspend_bench;
 
-  if (simgrid::config::get_value<bool>("smpi/barrier-collectives"))
-    smpi_deployment_startup_barrier(smpi_process()->get_instance_id());
-
   aid_t pid                          = simgrid::s4u::this_actor::get_pid();
   auto trace_recvcounts              = std::make_shared<std::vector<int>>();
   trace_recvcounts->insert(trace_recvcounts->end(), &recvcounts[0], &recvcounts[comm->size()]);
@@ -744,9 +740,6 @@ int PMPI_Ireduce_scatter_block(const void* sendbuf, void* recvbuf, int recvcount
 
   const SmpiBenchGuard suspend_bench;
 
-  if (simgrid::config::get_value<bool>("smpi/barrier-collectives"))
-    smpi_deployment_startup_barrier(smpi_process()->get_instance_id());
-
   int count = comm->size();
 
   aid_t pid                          = simgrid::s4u::this_actor::get_pid();
@@ -814,9 +807,6 @@ int PMPI_Ialltoall(const void* sendbuf, int sendcount, MPI_Datatype sendtype, vo
 
   const SmpiBenchGuard suspend_bench;
 
-  if (simgrid::config::get_value<bool>("smpi/barrier-collectives"))
-    smpi_deployment_startup_barrier(smpi_process()->get_instance_id());
-
   TRACE_smpi_comm_in(pid, request == MPI_REQUEST_IGNORED ? "PMPI_Alltoall" : "PMPI_Ialltoall",
                      new simgrid::instr::CollTIData(
                          request == MPI_REQUEST_IGNORED ? "alltoall" : "ialltoall", -1, -1.0,
@@ -870,9 +860,6 @@ int PMPI_Ialltoallv(const void* sendbuf, const int* sendcounts, const int* sendd
 
   const SmpiBenchGuard suspend_bench;
 
-  if (simgrid::config::get_value<bool>("smpi/barrier-collectives"))
-    smpi_deployment_startup_barrier(smpi_process()->get_instance_id());
-
   int send_size                      = 0;
   int recv_size                      = 0;
   auto trace_sendcounts              = std::make_shared<std::vector<int>>();
@@ -968,9 +955,6 @@ int PMPI_Ialltoallw(const void* sendbuf, const int* sendcounts, const int* sendd
 
   const SmpiBenchGuard suspend_bench;
 
-  if (simgrid::config::get_value<bool>("smpi/barrier-collectives"))
-    smpi_deployment_startup_barrier(smpi_process()->get_instance_id());
-
   int send_size                      = 0;
   int recv_size                      = 0;
   auto trace_sendcounts              = std::make_shared<std::vector<int>>();