Building version v5.0.6 with CUDA fails

[lahwaacz]

Building OpenMPI version v5.0.6 with CUDA fails with the following error:

coll_cuda_module.c: In function ‘mca_coll_cuda_comm_query’:
coll_cuda_module.c:107:42: error: assignment to ‘mca_coll_base_module_reduce_local_fn_t’ {aka ‘int (*)(const void *, void *, int,  struct ompi_datatype_t *, struct ompi_op_t *, struct mca_coll_base_module_2_4_0_t *)’} from incompatible pointer type ‘int (*)(const void *, void *, size_t,  struct ompi_datatype_t *, struct ompi_op_t *, mca_coll_base_module_t *)’ {aka ‘int (*)(const void *, void *, long unsigned int,  struct ompi_datatype_t *, struct ompi_op_t *, struct mca_coll_base_module_2_4_0_t *)’} [-Wincompatible-pointer-types]
  107 |     cuda_module->super.coll_reduce_local = mca_coll_cuda_reduce_local;
      |                                          ^

[lahwaacz]

Seems to be caused by e3ad86e

It specifies the function with size_t count parameter, which does not work because 4d7c65d was done only on the main branch, not on v5.0.x.

[bosilca]

SC24 travel day, can't do more than this:

diff --git a/ompi/mca/coll/cuda/coll_cuda.h b/ompi/mca/coll/cuda/coll_cuda.h
index afedc632ee..4b3ecc647e 100644
--- a/ompi/mca/coll/cuda/coll_cuda.h
+++ b/ompi/mca/coll/cuda/coll_cuda.h
@@ -54,7 +54,7 @@ int mca_coll_cuda_reduce(const void *sbuf, void *rbuf, int count,
                          struct ompi_communicator_t *comm,
                          mca_coll_base_module_t *module);
 
-int mca_coll_cuda_reduce_local(const void *sbuf, void *rbuf, size_t count,
+int mca_coll_cuda_reduce_local(const void *sbuf, void *rbuf, int count,
                                struct ompi_datatype_t *dtype,
                                struct ompi_op_t *op,
                                mca_coll_base_module_t *module);
diff --git a/ompi/mca/coll/cuda/coll_cuda_reduce.c b/ompi/mca/coll/cuda/coll_cuda_reduce.c
index 7743a07874..e165a1d9bb 100644
--- a/ompi/mca/coll/cuda/coll_cuda_reduce.c
+++ b/ompi/mca/coll/cuda/coll_cuda_reduce.c
@@ -85,7 +85,7 @@ mca_coll_cuda_reduce(const void *sbuf, void *rbuf, int count,
 }
 
 int
-mca_coll_cuda_reduce_local(const void *sbuf, void *rbuf, size_t count,
+mca_coll_cuda_reduce_local(const void *sbuf, void *rbuf, int count,
                            struct ompi_datatype_t *dtype,
                            struct ompi_op_t *op,
                            mca_coll_base_module_t *module)

[edgargabriel]

did we not backport the cuda compilation check to the 5.0.x branch? That should/would have caught the issue

[lahwaacz]

@bosilca @janjust Any progress? This is blocking us from upgrading to the latest release.

[janjust]

@lahwaacz back from SC - does the above patch work for you? For now we have to consider v5.0.6 broken for cuda builds, I'll push an rc1 asap. with a release week after "hopefully"

[lahwaacz]

@janjust The patch makes the build pass, but I have no idea if the patched release actually works - obviously nobody tested it yet with cuda...

[janjust]

So that's the thing, I was about to ask on slack/general

But for some odd reason, the v5.0.6 builds coll/cuda just fine for me.

$ ./ompi_info -a | grep cuda
30:  Configure command line: '--prefix=/hpc/mtr_scrap/users/tomislavj/ompi-dev/openmpi-5.0.6/install' '--with-cuda=/hpc/local/oss/cuda12.6.1/redhat8' '--with-ucx=/hpc/mtr_scrap/users/tomislavj/ompi-dev/ucx-build/install' '--with-libevent=internal' '--enable-prte-prefix-by-default' '--enable-mpi1-compatibility' '--without-xpmem' '--with-pmix=internal' '--with-prrte=internal' '--enable-mca-dso=all' '--disable-oshmem' '--enable-mpi-fortran=no'
125:          MPI extensions: affinity, cuda, ftmpi, rocm, shortfloat
136:         MCA accelerator: cuda (MCA v2.1.0, API v1.0.0, Component v5.0.6)
142:                 MCA btl: smcuda (MCA v2.1.0, API v3.3.0, Component v5.0.6)
172:                MCA coll: cuda (MCA v2.1.0, API v2.4.0, Component v5.0.6) 

$ ./configure --prefix=/hpc/mtr_scrap/users/tomislavj/ompi-dev/openmpi-5.0.6/install --with-cuda=/hpc/local      /oss/cuda12.6.1/redhat8 --with-ucx=/hpc/mtr_scrap/users/tomislavj/ompi-dev/ucx-build/install --with-libevent=      internal --enable-prte-prefix-by-default --enable-mpi1-compatibility --without-xpmem --with-pmix=internal --w      ith-prrte=internal --enable-mca-dso=all --disable-oshmem --enable-mpi-fortran=no

And this is using the source tarball

[janjust]

@lahwaacz what compiler are you using, just curious
And what is your configure command?

[janjust]

nvm, I think I got it, @bosilca pointed out it's due to the -Werror flag missing

[janjust]

fixed with #12934

[lahwaacz]

@janjust Thanks! Will you make a new release with the fix?