Skip to content

Commit

Permalink
coll/libnbc/ialltoallv: skip send/recv 0-byte data
Browse files Browse the repository at this point in the history 
As per MPI specification the amount of data sent must be equal to the
amount of data received for each communication pair, and therefore
both count and datatype size should be accounted for to determine if
the data is 0-byte and therefore skippable.

Signed-off-by: Wenduo Wang <[email protected]>
  • Loading branch information
@wenduwan
wenduwan committed Jan 13, 2024
1 parent 477be61 commit be39f1b
Showing 1 changed file with 39 additions and 20 deletions.
59 changes: 39 additions & 20 deletions ompi/mca/coll/libnbc/nbc_ialltoallv.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -48,6 +48,7 @@ static int nbc_alltoallv_init(const void* sendbuf, const int *sendcounts, const
mca_coll_base_module_t *module, bool persistent)
{
int rank, p, res;
size_t sndsz, rcvsz;
MPI_Aint sndext, rcvext;
NBC_Schedule *schedule;
char *rbuf, *sbuf, inplace;
Expand All @@ -60,6 +61,7 @@ static int nbc_alltoallv_init(const void* sendbuf, const int *sendcounts, const
rank = ompi_comm_rank (comm);
p = ompi_comm_size (comm);

ompi_datatype_type_size(recvtype, &rcvsz);
res = ompi_datatype_type_extent (recvtype, &rcvext);
if (MPI_SUCCESS != res) {
NBC_Error("MPI Error in ompi_datatype_type_extent() (%i)", res);
Expand Down Expand Up @@ -92,22 +94,29 @@ static int nbc_alltoallv_init(const void* sendbuf, const int *sendcounts, const
sendcounts = recvcounts;
sdispls = rdispls;
sndext = rcvext;
sndsz = rcvsz;
} else {
ompi_datatype_type_size(sendtype, &sndsz);
res = ompi_datatype_type_extent (sendtype, &sndext);
if (MPI_SUCCESS != res) {
NBC_Error("MPI Error in ompi_datatype_type_extent() (%i)", res);
return res;
}
}

if (0 == sndsz || 0 == rcvsz) {
/* Nothing to exchange */
ompi_coll_base_nbc_reserve_tags(comm, 1);
return nbc_get_noop_request(persistent, request);
}

schedule = OBJ_NEW(NBC_Schedule);
if (OPAL_UNLIKELY(NULL == schedule)) {
free(tmpbuf);
return OMPI_ERR_OUT_OF_RESOURCE;
}


if (!inplace && sendcounts[rank] != 0) {
if (!inplace && 0 < sendcounts[rank]) {
rbuf = (char *) recvbuf + rdispls[rank] * rcvext;
sbuf = (char *) sendbuf + sdispls[rank] * sndext;
res = NBC_Sched_copy (sbuf, false, sendcounts[rank], sendtype,
Expand Down Expand Up @@ -177,10 +186,18 @@ static int nbc_alltoallv_inter_init (const void* sendbuf, const int *sendcounts,
mca_coll_base_module_t *module, bool persistent)
{
int res, rsize;
size_t sndsz, rcvsz;
MPI_Aint sndext, rcvext;
NBC_Schedule *schedule;
ompi_coll_libnbc_module_t *libnbc_module = (ompi_coll_libnbc_module_t*) module;

ompi_datatype_type_size(sendtype, &sndsz);
ompi_datatype_type_size(recvtype, &rcvsz);
if (0 == sndsz || 0 == rcvsz) {
/* Nothing to exchange */
ompi_coll_base_nbc_reserve_tags(comm, 1);
return nbc_get_noop_request(persistent, request);
}

res = ompi_datatype_type_extent(sendtype, &sndext);
if (MPI_SUCCESS != res) {
Expand All @@ -203,7 +220,7 @@ static int nbc_alltoallv_inter_init (const void* sendbuf, const int *sendcounts,

for (int i = 0; i < rsize; i++) {
/* post all sends */
if (sendcounts[i] != 0) {
if (0 < sendcounts[i]) {
char *sbuf = (char *) sendbuf + sdispls[i] * sndext;
res = NBC_Sched_send (sbuf, false, sendcounts[i], sendtype, i, schedule, false);
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
Expand All @@ -212,7 +229,7 @@ static int nbc_alltoallv_inter_init (const void* sendbuf, const int *sendcounts,
}
}
/* post all receives */
if (recvcounts[i] != 0) {
if (0 < recvcounts[i]) {
char *rbuf = (char *) recvbuf + rdispls[i] * rcvext;
res = NBC_Sched_recv (rbuf, false, recvcounts[i], recvtype, i, schedule, false);
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
Expand Down Expand Up @@ -272,7 +289,7 @@ static inline int a2av_sched_linear(int rank, int p, NBC_Schedule *schedule,
}

/* post send */
if (sendcounts[i] != 0) {
if (0 < sendcounts[i]) {
char *sbuf = ((char *) sendbuf) + (sdispls[i] * sndext);
res = NBC_Sched_send(sbuf, false, sendcounts[i], sendtype, i, schedule, false);
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
Expand All @@ -281,7 +298,7 @@ static inline int a2av_sched_linear(int rank, int p, NBC_Schedule *schedule,
}

/* post receive */
if (recvcounts[i] != 0) {
if (0 < recvcounts[i]) {
char *rbuf = ((char *) recvbuf) + (rdispls[i] * rcvext);
res = NBC_Sched_recv(rbuf, false, recvcounts[i], recvtype, i, schedule, false);
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
Expand All @@ -306,7 +323,7 @@ static inline int a2av_sched_pairwise(int rank, int p, NBC_Schedule *schedule,
int rcvpeer = (rank + p - i) %p;

/* post send */
if (sendcounts[sndpeer] != 0) {
if (0 < sendcounts[sndpeer]) {
char *sbuf = ((char *) sendbuf) + (sdispls[sndpeer] * sndext);
res = NBC_Sched_send(sbuf, false, sendcounts[sndpeer], sendtype, sndpeer, schedule, false);
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
Expand All @@ -315,7 +332,7 @@ static inline int a2av_sched_pairwise(int rank, int p, NBC_Schedule *schedule,
}

/* post receive */
if (recvcounts[rcvpeer] != 0) {
if (0 < recvcounts[rcvpeer]) {
char *rbuf = ((char *) recvbuf) + (rdispls[rcvpeer] * rcvext);
res = NBC_Sched_recv(rbuf, false, recvcounts[rcvpeer], recvtype, rcvpeer, schedule, true);
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
Expand All @@ -338,34 +355,34 @@ static inline int a2av_sched_inplace(int rank, int p, NBC_Schedule *schedule,
char *sbuf = (char *) buf + displs[speer] * ext;
char *rbuf = (char *) buf + displs[rpeer] * ext;

if (0 != counts[rpeer]) {
if (0 < counts[rpeer]) {
res = NBC_Sched_copy (rbuf, false, counts[rpeer], type,
(void *)(-gap), true, counts[rpeer], type,
schedule, true);
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
return res;
}
}
if (0 != counts[speer]) {
if (0 < counts[speer]) {
res = NBC_Sched_send (sbuf, false , counts[speer], type, speer, schedule, false);
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
return res;
}
}
if (0 != counts[rpeer]) {
if (0 < counts[rpeer]) {
res = NBC_Sched_recv (rbuf, false , counts[rpeer], type, rpeer, schedule, true);
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
return res;
}
}

if (0 != counts[rpeer]) {
if (0 < counts[rpeer]) {
res = NBC_Sched_send ((void *)(-gap), true, counts[rpeer], type, rpeer, schedule, false);
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
return res;
}
}
if (0 != counts[speer]) {
if (0 < counts[speer]) {
res = NBC_Sched_recv (sbuf, false, counts[speer], type, speer, schedule, true);
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
return res;
Expand All @@ -374,15 +391,17 @@ static inline int a2av_sched_inplace(int rank, int p, NBC_Schedule *schedule,
}
if (0 == (p%2)) {
int peer = (rank + p/2) % p;

char *tbuf = (char *) buf + displs[peer] * ext;
res = NBC_Sched_copy (tbuf, false, counts[peer], type,
(void *)(-gap), true, counts[peer], type,
schedule, true);
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
return res;

if (0 < counts[peer]) {
res = NBC_Sched_copy(tbuf, false, counts[peer], type, (void *) (-gap), true, counts[peer],
type, schedule, true);
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
return res;
}
}
if (0 != counts[peer]) {

if (0 < counts[peer]) {
res = NBC_Sched_send ((void *)(-gap), true , counts[peer], type, peer, schedule, false);
if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
return res;
Expand Down

0 comments on commit be39f1b

Please sign in to comment.