/*
* Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2015 The University of Tennessee and The University
* of Tennessee Research Foundation. All rights
* reserved.
* Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
* University of Stuttgart. All rights reserved.
* Copyright (c) 2004-2005 The Regents of the University of California.
* All rights reserved.
* Copyright (c) 2015 Research Organization for Information Science
* and Technology (RIST). All rights reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#include "ompi_config.h"
#include "mpi.h"
#include "opal/util/bit_ops.h"
#include "ompi/constants.h"
#include "ompi/communicator/communicator.h"
#include "ompi/mca/coll/base/coll_tags.h"
#include "ompi/mca/coll/base/coll_base_functions.h"
#include "coll_base_topo.h"
/*
* Some static helpers.
*/
static int pown( int fanout, int num )
{
int j, p = 1;
if( num < 0 ) return 0;
if (1==num) return fanout;
if (2==fanout) {
return p<<num;
}
else {
for( j = 0; j < num; j++ ) { p*= fanout; }
}
return p;
}
static int calculate_level( int fanout, int rank )
{
int level, num;
if( rank < 0 ) return -1;
for( level = 0, num = 0; num <= rank; level++ ) {
num += pown(fanout, level);
}
return level-1;
}
static int calculate_num_nodes_up_to_level( int fanout, int level )
{
/* just use geometric progression formula for sum:
a^0+a^1+...a^(n-1) = (a^n-1)/(a-1) */
return ((pown(fanout,level) - 1)/(fanout - 1));
}
/*
* And now the building functions.
*
* An example for fanout = 2, comm_size = 7
*
* 0 <-- delta = 1 (fanout^0)
* / \
* 1 2 <-- delta = 2 (fanout^1)
* / \ / \
* 3 5 4 6 <-- delta = 4 (fanout^2)
*/
ompi_coll_tree_t*
ompi_coll_base_topo_build_tree( int fanout,
struct ompi_communicator_t* comm,
int root )
{
int rank, size, schild, sparent, shiftedrank, i;
int level; /* location of my rank in the tree structure of size */
int delta; /* number of nodes on my level */
int slimit; /* total number of nodes on levels above me */
ompi_coll_tree_t* tree;
OPAL_OUTPUT((ompi_coll_base_framework.framework_output, "coll:base:topo_build_tree Building fo %d rt %d", fanout, root));
if (fanout<1) {
OPAL_OUTPUT((ompi_coll_base_framework.framework_output, "coll:base:topo_build_tree invalid fanout %d", fanout));
return NULL;
}
if (fanout>MAXTREEFANOUT) {
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,"coll:base:topo_build_tree invalid fanout %d bigger than max %d", fanout, MAXTREEFANOUT));
return NULL;
}
/*
* Get size and rank of the process in this communicator
*/
size = ompi_comm_size(comm);
rank = ompi_comm_rank(comm);
tree = (ompi_coll_tree_t*)malloc(sizeof(ompi_coll_tree_t));
if (!tree) {
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,"coll:base:topo_build_tree PANIC::out of memory"));
return NULL;
}
tree->tree_root = MPI_UNDEFINED;
tree->tree_nextsize = MPI_UNDEFINED;
/*
* Set root
*/
tree->tree_root = root;
/*
* Initialize tree
*/
tree->tree_fanout = fanout;
tree->tree_bmtree = 0;
tree->tree_root = root;
tree->tree_prev = -1;
tree->tree_nextsize = 0;
for( i = 0; i < fanout; i++ ) {
tree->tree_next[i] = -1;
}
/* return if we have less than 2 processes */
if( size < 2 ) {
return tree;
}
/*
* Shift all ranks by root, so that the algorithm can be
* designed as if root would be always 0
* shiftedrank should be used in calculating distances
* and position in tree
*/
shiftedrank = rank - root;
if( shiftedrank < 0 ) {
shiftedrank += size;
}
/* calculate my level */
level = calculate_level( fanout, shiftedrank );
delta = pown( fanout, level );
/* find my children */
for( i = 0; i < fanout; i++ ) {
schild = shiftedrank + delta * (i+1);
if( schild < size ) {
tree->tree_next[i] = (schild+root)%size;
tree->tree_nextsize = tree->tree_nextsize + 1;
} else {
break;
}
}
/* find my parent */
slimit = calculate_num_nodes_up_to_level( fanout, level );
sparent = shiftedrank;
if( sparent < fanout ) {
sparent = 0;
} else {
while( sparent >= slimit ) {
sparent -= delta/fanout;
}
}
tree->tree_prev = (sparent+root)%size;
return tree;
}
/*
* Constructs in-order binary tree which can be used for non-commutative reduce
* operations.
* Root of this tree is always rank (size-1) and fanout is 2.
* Here are some of the examples of this tree:
* size == 2 size == 3 size == 4 size == 9
* 1 2 3 8
* / / \ / \ / \
* 0 1 0 2 1 7 3
* / / \ / \
* 0 6 5 2 1
* / /
* 4 0
*/
ompi_coll_tree_t*
ompi_coll_base_topo_build_in_order_bintree( struct ompi_communicator_t* comm )
{
int rank, size, myrank, rightsize, delta, parent, lchild, rchild;
ompi_coll_tree_t* tree;
/*
* Get size and rank of the process in this communicator
*/
size = ompi_comm_size(comm);
rank = ompi_comm_rank(comm);
tree = (ompi_coll_tree_t*)malloc(sizeof(ompi_coll_tree_t));
if (!tree) {
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,
"coll:base:topo_build_tree PANIC::out of memory"));
return NULL;
}
tree->tree_root = MPI_UNDEFINED;
tree->tree_nextsize = MPI_UNDEFINED;
/*
* Initialize tree
*/
tree->tree_fanout = 2;
tree->tree_bmtree = 0;
tree->tree_root = size - 1;
tree->tree_prev = -1;
tree->tree_nextsize = 0;
tree->tree_next[0] = -1;
tree->tree_next[1] = -1;
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,
"coll:base:topo_build_in_order_tree Building fo %d rt %d",
tree->tree_fanout, tree->tree_root));
/*
* Build the tree
*/
myrank = rank;
parent = size - 1;
delta = 0;
while ( 1 ) {
/* Compute the size of the right subtree */
rightsize = size >> 1;
/* Determine the left and right child of this parent */
lchild = -1;
rchild = -1;
if (size - 1 > 0) {
lchild = parent - 1;
if (lchild > 0) {
rchild = rightsize - 1;
}
}
/* The following cases are possible: myrank can be
- a parent,
- belong to the left subtree, or
- belong to the right subtee
Each of the cases need to be handled differently.
*/
if (myrank == parent) {
/* I am the parent:
- compute real ranks of my children, and exit the loop. */
if (lchild >= 0) tree->tree_next[0] = lchild + delta;
if (rchild >= 0) tree->tree_next[1] = rchild + delta;
break;
}
if (myrank > rchild) {
/* I belong to the left subtree:
- If I am the left child, compute real rank of my parent
- Iterate down through tree:
compute new size, shift ranks down, and update delta.
*/
if (myrank == lchild) {
tree->tree_prev = parent + delta;
}
size = size - rightsize - 1;
delta = delta + rightsize;
myrank = myrank - rightsize;
parent = size - 1;
} else {
/* I belong to the right subtree:
- If I am the right child, compute real rank of my parent
- Iterate down through tree:
compute new size and parent,
but the delta and rank do not need to change.
*/
if (myrank == rchild) {
tree->tree_prev = parent + delta;
}
size = rightsize;
parent = rchild;
}
}
if (tree->tree_next[0] >= 0) { tree->tree_nextsize = 1; }
if (tree->tree_next[1] >= 0) { tree->tree_nextsize += 1; }
return tree;
}
int ompi_coll_base_topo_destroy_tree( ompi_coll_tree_t** tree )
{
ompi_coll_tree_t *ptr;
if ((!tree)||(!*tree)) {
return OMPI_SUCCESS;
}
ptr = *tree;
free (ptr);
*tree = NULL; /* mark tree as gone */
return OMPI_SUCCESS;
}
/*
*
* Here are some of the examples of this tree:
* size == 2 size = 4 size = 8
* 0 0 0
* / | \ / | \
* 1 2 1 4 2 1
* | | |\
* 3 6 5 3
* |
* 7
*/
ompi_coll_tree_t*
ompi_coll_base_topo_build_bmtree( struct ompi_communicator_t* comm,
int root )
{
int childs = 0, rank, size, mask = 1, index, remote, i;
ompi_coll_tree_t *bmtree;
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,"coll:base:topo:build_bmtree rt %d", root));
/*
* Get size and rank of the process in this communicator
*/
size = ompi_comm_size(comm);
rank = ompi_comm_rank(comm);
index = rank -root;
bmtree = (ompi_coll_tree_t*)malloc(sizeof(ompi_coll_tree_t));
if (!bmtree) {
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,"coll:base:topo:build_bmtree PANIC out of memory"));
return NULL;
}
bmtree->tree_bmtree = 1;
bmtree->tree_root = MPI_UNDEFINED;
bmtree->tree_nextsize = MPI_UNDEFINED;
for( i = 0;i < MAXTREEFANOUT; i++ ) {
bmtree->tree_next[i] = -1;
}
if( index < 0 ) index += size;
mask = opal_next_poweroftwo(index);
/* Now I can compute my father rank */
if( root == rank ) {
bmtree->tree_prev = root;
} else {
remote = (index ^ (mask >> 1)) + root;
if( remote >= size ) remote -= size;
bmtree->tree_prev = remote;
}
/* And now let's fill my childs */
while( mask < size ) {
remote = (index ^ mask);
if( remote >= size ) break;
remote += root;
if( remote >= size ) remote -= size;
if (childs==MAXTREEFANOUT) {
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,"coll:base:topo:build_bmtree max fanout incorrect %d needed %d", MAXTREEFANOUT, childs));
free(bmtree);
return NULL;
}
bmtree->tree_next[childs] = remote;
mask <<= 1;
childs++;
}
bmtree->tree_nextsize = childs;
bmtree->tree_root = root;
return bmtree;
}
/*
* Constructs in-order binomial tree which can be used for gather/scatter
* operations.
*
* Here are some of the examples of this tree:
* size == 2 size = 4 size = 8
* 0 0 0
* / / | / | \
* 1 1 2 1 2 4
* | | | \
* 3 3 5 6
* |
* 7
*/
ompi_coll_tree_t*
ompi_coll_base_topo_build_in_order_bmtree( struct ompi_communicator_t* comm,
int root )
{
int childs = 0, rank, vrank, size, mask = 1, remote, i;
ompi_coll_tree_t *bmtree;
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,"coll:base:topo:build_in_order_bmtree rt %d", root));
/*
* Get size and rank of the process in this communicator
*/
size = ompi_comm_size(comm);
rank = ompi_comm_rank(comm);
vrank = (rank - root + size) % size;
bmtree = (ompi_coll_tree_t*)malloc(sizeof(ompi_coll_tree_t));
if (!bmtree) {
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,"coll:base:topo:build_bmtree PANIC out of memory"));
return NULL;
}
bmtree->tree_bmtree = 1;
bmtree->tree_root = MPI_UNDEFINED;
bmtree->tree_nextsize = MPI_UNDEFINED;
for(i=0;i<MAXTREEFANOUT;i++) {
bmtree->tree_next[i] = -1;
}
if (root == rank) {
bmtree->tree_prev = root;
}
while (mask < size) {
remote = vrank ^ mask;
if (remote < vrank) {
bmtree->tree_prev = (remote + root) % size;
break;
} else if (remote < size) {
bmtree->tree_next[childs] = (remote + root) % size;
childs++;
if (childs==MAXTREEFANOUT) {
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,
"coll:base:topo:build_bmtree max fanout incorrect %d needed %d",
MAXTREEFANOUT, childs));
free(bmtree);
return NULL;
}
}
mask <<= 1;
}
bmtree->tree_nextsize = childs;
bmtree->tree_root = root;
return bmtree;
}
ompi_coll_tree_t*
ompi_coll_base_topo_build_chain( int fanout,
struct ompi_communicator_t* comm,
int root )
{
int i, maxchainlen, mark, head, len, rank, size, srank /* shifted rank */;
ompi_coll_tree_t *chain;
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,"coll:base:topo:build_chain fo %d rt %d", fanout, root));
/*
* Get size and rank of the process in this communicator
*/
size = ompi_comm_size(comm);
rank = ompi_comm_rank(comm);
if( fanout < 1 ) {
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,"coll:base:topo:build_chain WARNING invalid fanout of ZERO, forcing to 1 (pipeline)!"));
fanout = 1;
}
if (fanout>MAXTREEFANOUT) {
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,"coll:base:topo:build_chain WARNING invalid fanout %d bigger than max %d, forcing to max!", fanout, MAXTREEFANOUT));
fanout = MAXTREEFANOUT;
}
/*
* Allocate space for topology arrays if needed
*/
chain = (ompi_coll_tree_t*)malloc( sizeof(ompi_coll_tree_t) );
if (!chain) {
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,"coll:base:topo:build_chain PANIC out of memory"));
fflush(stdout);
return NULL;
}
chain->tree_root = MPI_UNDEFINED;
chain->tree_nextsize = -1;
for(i=0;i<fanout;i++) chain->tree_next[i] = -1;
/*
* Set root & numchain
*/
chain->tree_root = root;
if( (size - 1) < fanout ) {
chain->tree_nextsize = size-1;
fanout = size-1;
} else {
chain->tree_nextsize = fanout;
}
/*
* Shift ranks
*/
srank = rank - root;
if (srank < 0) srank += size;
/*
* Special case - fanout == 1
*/
if( fanout == 1 ) {
if( srank == 0 ) chain->tree_prev = -1;
else chain->tree_prev = (srank-1+root)%size;
if( (srank + 1) >= size) {
chain->tree_next[0] = -1;
chain->tree_nextsize = 0;
} else {
chain->tree_next[0] = (srank+1+root)%size;
chain->tree_nextsize = 1;
}
return chain;
}
/* Let's handle the case where there is just one node in the communicator */
if( size == 1 ) {
chain->tree_next[0] = -1;
chain->tree_nextsize = 0;
chain->tree_prev = -1;
return chain;
}
/*
* Calculate maximum chain length
*/
maxchainlen = (size-1) / fanout;
if( (size-1) % fanout != 0 ) {
maxchainlen++;
mark = (size-1)%fanout;
} else {
mark = fanout+1;
}
/*
* Find your own place in the list of shifted ranks
*/
if( srank != 0 ) {
int column;
if( srank-1 < (mark * maxchainlen) ) {
column = (srank-1)/maxchainlen;
head = 1+column*maxchainlen;
len = maxchainlen;
} else {
column = mark + (srank-1-mark*maxchainlen)/(maxchainlen-1);
head = mark*maxchainlen+1+(column-mark)*(maxchainlen-1);
len = maxchainlen-1;
}
if( srank == head ) {
chain->tree_prev = 0; /*root*/
} else {
chain->tree_prev = srank-1; /* rank -1 */
}
if( srank == (head + len - 1) ) {
chain->tree_next[0] = -1;
chain->tree_nextsize = 0;
} else {
if( (srank + 1) < size ) {
chain->tree_next[0] = srank+1;
chain->tree_nextsize = 1;
} else {
chain->tree_next[0] = -1;
chain->tree_nextsize = 0;
}
}
chain->tree_prev = (chain->tree_prev+root)%size;
if( chain->tree_next[0] != -1 ) {
chain->tree_next[0] = (chain->tree_next[0]+root)%size;
}
} else {
/*
* Unshift values
*/
chain->tree_prev = -1;
chain->tree_next[0] = (root+1)%size;
for( i = 1; i < fanout; i++ ) {
chain->tree_next[i] = chain->tree_next[i-1] + maxchainlen;
if( i > mark ) {
chain->tree_next[i]--;
}
chain->tree_next[i] %= size;
}
chain->tree_nextsize = fanout;
}
return chain;
}
int ompi_coll_base_topo_dump_tree (ompi_coll_tree_t* tree, int rank)
{
int i;
OPAL_OUTPUT((ompi_coll_base_framework.framework_output, "coll:base:topo:topo_dump_tree %1d tree root %d"
" fanout %d BM %1d nextsize %d prev %d",
rank, tree->tree_root, tree->tree_bmtree, tree->tree_fanout,
tree->tree_nextsize, tree->tree_prev));
if( tree->tree_nextsize ) {
for( i = 0; i < tree->tree_nextsize; i++ )
OPAL_OUTPUT((ompi_coll_base_framework.framework_output,"[%1d] %d", i, tree->tree_next[i]));
}
return (0);
}