Fixes a wrong answer from MPI_Ireduce when the red_sched_chain()
path was taken (which only happens for np<=4 and mesgsize>=64k).
The way libnbc treats MPI_IN_PLACE is to set sbuf == rbuf, and
whether an algorithm will work cleanly or not after that depends on the
details.
In this case the last steps of the algorithm amounted to
(right neighbor is sending us reduction results from ranks 1..n-1)
recv into rbuf from right neighbor
add the contribution from our sbuf into rbuf
this would be fine in general, but if sbuf==rbuf, that recv overwrites
the sbuf. I changed it to recv into a tmpbuf if MPI_IN_PLACE was used.
Signed-off-by: Geoffrey Paulsen <gpaulsen@us.ibm.com>
MPI_Allgatherv with MPI_IN_PLACE reads data from wrong location.
They were locating the MPI_IN_PLACE send buffer as
```c
send_buf = (char*)rbuf;
for (i = 0; i < rank; ++i) {
send_buf += ((ptrdiff_t)rcounts[i] * extent);
}
```
when it should be
```c
send_buf = (char*)rbuf;
send_buf += ((ptrdiff_t)disps[rank] * extent);
```
because disps[] specifies where things are in the v-style buffers.
Signed-off-by: Joshua Hursey <jhursey@us.ibm.com>
Adds the new API hcoll_conetxt_free that resolves the issues
observed with the ctx cache and group_destroy_notify.
Signed-off-by: Valentin Petrov <valentinp@mellanox.com>
protect the mca_coll_libnbc_component.active_requests list with
the new mca_coll_libnbc_component.lock mutex.
Thanks Jie Hu for the report
Signed-off-by: Gilles Gouaillardet <gilles@rist.or.jp>
- instead of coll_base_comm_get_reqs(2) for irecv/isend, use only
one request allocated in the stack and do a irecv/send
- instead of ompi_request_wait_all(2), simpy ompi_request_wait
Signed-off-by: Gilles Gouaillardet <gilles@rist.or.jp>
* If (legal) non-uniform data type signatures are used in ibcast
then the chosen algorithm may fail on the request, and worst case
it could produce wrong answers.
* Add an MCA parameter that, by default, protects the user from this
scenario. If the user really wants to use it then they have to
'opt-in' by setting the following parameter to false:
- `-mca coll_libnbc_ibcast_skip_dt_decision f`
* Once the following Issues are resolved then this parameter can
be removed.
- https://github.com/open-mpi/ompi/issues/2256
- https://github.com/open-mpi/ompi/issues/1763
Signed-off-by: Joshua Hursey <jhursey@us.ibm.com>
Adds mapping of the MPI Fortran pair types (2INTEGER, 2REAL, 2DBLPREC)
to the corresponding hcoll dtypes.
Signed-off-by: Valentin Petrov <valentinp@mellanox.com>
* If an error is detected internal to libnbc (e.g., PML truncation error)
this patch makes sure that the request is completed and the `MPI_ERROR`
field is set approprately.
* Make an attempt to cleanup outstanding requests before returning.
- This is a "best attempt" since not all PMLs support canceling requests.
In order to optimize for MPI_IN_PLACE, data is sent from the receive buffer.
consequently, it should be sent with the receive type and count.
Thanks Josh Hursey for the report and test case
Refs open-mpi/ompi#2256
if sendbuf is equal to recvbuf, that should not be interpreted
as equivalent to MPI_IN_PLACE on the non root rank(s)
Thanks Valentin Petrov for the report
predefined datatypes such as MPI_LONG_DOUBLE_INT are not really contiguous,
so use span as returned by opal_datatype_span() instead of type extent,
otherwise data might be written above allocated memory.
Thanks Valentin Petrov for the report
