diff --git a/mpiuse.c b/mpiuse.c
index c194495b98c0f4f8c2fb06d52c3da45268c2f3d1..77bd4a1009172ede87c6f6623ba60934d1c39359 100644
--- a/mpiuse.c
+++ b/mpiuse.c
@@ -285,28 +285,77 @@ static double gauss_rand_upper(void) {
* @param nr_nodes the number of ranks that will be used.
* @param nr_logs the number of logs to generate per rank.
* @param size bytes per message, unless random when this is the maximum
- * and the minimum is 1 for uniform and 2.5 sigma for gaussian.
+ * and the minimum is 1 for uniform, if using a gaussian
+ * distribution the value is a 2.5 sigma, for a CDF based
+ * selection this is just a scale factor of the values.
* @param random whether to use random sizes.
* @param seed the random seed, use same for fixed sequences.
- * @param uniform whether to use a uniform distribution.
+ * @param uniform whether to use a uniform distribution other gaussian, unless
+ * cdf is defined, in which case this parameter is ignored.
+ * @param cdf text file containing a normalized CDF to use as a basis for inverse
+ * transform sampling of the randoms. NULL for no file.
*/
void mpiuse_log_generate(int nr_nodes, int nr_logs, int size, int random,
- long int seed, int uniform) {
+ long int seed, int uniform, const char *cdf) {
- /* Each rank exchanges messages with all the others and each "log" has the
- * same size. */
+ /* Only used for CDF, may need to increase these. */
+ int nvals = 0;
+ double imin[256], imax[256], value[256];
+
+ /* Note that each rank exchanges messages with all the others and each "log"
+ * has the same size. */
+ /* Set seed. */
if (random) srand48(seed);
+ /* Check for CDF. This should be based on some real distribution, the format
+ * is same as output from TOPCAT, i.e. bin-low, bin-high, value space
+ * separated values. Note the value column should be normalised into the
+ * range 0 to 1 so that it maps into a uniform random distribution. */
+ if (cdf != NULL) {
+ FILE *infile = fopen(cdf, "r");
+ if (infile == NULL) error("Failed to open CDF file: %s", cdf);
+ char line[132];
+ while (!feof(infile)) {
+ if (fgets(line, 132, infile) != NULL) {
+ if (line[0] != '#') {
+ int nread = sscanf(line, "%lf %lf %lf", &imin[nvals], &imax[nvals],
+ &value[nvals]);
+ if (nread == 3) nvals++;
+ }
+ }
+ }
+ fclose(infile);
+ }
+
+ /* Message tags increment with across rank logs. */
int tag = 1;
for (int k = 0; k < nr_logs; k++) {
/* Set size for this messages. */
int logsize = size;
if (random) {
- if (uniform) {
+ if (cdf) {
+ /* CDF randoms. */
+ double rand = drand48();
+
+ /* Binary search for containing bin for this rand. */
+ unsigned int lower = 0;
+ unsigned int upper = nvals;
+ unsigned int middle = 0;
+ while (lower < upper) {
+ middle = (upper + lower) / 2;
+ if (rand > value[middle])
+ lower = middle + 1;
+ else
+ upper = middle;
+ }
+ logsize = 0.5 * (imax[middle] + imin[middle]);
+
+ } else if (uniform) {
+ /* Uniform randoms in the range 0 to 1 */
logsize = (drand48() * (double)size) + 1;
} else {
- // Gaussian so no maximum, assume size is 2.5 sigma.
+ // Gaussian randoms so no maximum, assume size is 2.5 sigma.
logsize = (gauss_rand_upper() * (double)size * 0.25) + 1;
}
}
diff --git a/mpiuse.h b/mpiuse.h
index feae1e6f7999a30fb79c9aa4b1ed9844a59a1fce..f621698be1f8cc8cf14a029e55654ce08dfcfacf 100644
--- a/mpiuse.h
+++ b/mpiuse.h
@@ -102,6 +102,6 @@ int mpiuse_nr_ranks(void);
void mpiuse_dump_logs(int nranks, const char *logfile);
void mpiuse_log_generate(int nr_nodes, int nr_logs, int size, int random,
- long int seed, int uniform);
+ long int seed, int uniform, const char *cdf);
#endif /* SWIFT_MPIUSE_H */
diff --git a/swiftmpifakestepsim.c b/swiftmpifakestepsim.c
index 7d991b752bbc1fb292414f65bf5e3bfd116d1d24..80b9e5e3ef046e67e41fcdf11cc52b3ed2c74d5c 100644
--- a/swiftmpifakestepsim.c
+++ b/swiftmpifakestepsim.c
@@ -38,8 +38,8 @@ static int verbose = 0;
/* Set a data pattern and check we get this back, slow... */
static int datacheck = 0;
-/* Fixed seed for pseudorandoms. */
-static long int seed = 1987654321;
+/* Default seed for pseudorandoms. */
+static long int default_seed = 1987654321;
/* The local queues. */
static struct mpiuse_log_entry **volatile reqs_queue;
@@ -339,11 +339,13 @@ static void pick_logs(void) {
* @brief usage help.
*/
static void usage(char *argv[]) {
- fprintf(stderr, "Usage: %s [-vf] nr_messages logfile.dat\n",
+ fprintf(stderr, "Usage: %s [-vfgcx] nr_messages logfile.dat\n",
argv[0]);
- fprintf(stderr, " options: -v verbose, -d data check, -s size (bytes), "
- "-r uniform random from 1 to size, "
- "-r -g half gaussian random from 1 with 2.5 sigma size.\n");
+ fprintf(stderr, " options: -v verbose, -d data check, -s size (bytes/scale), \n"
+ "\t[-r uniform random from 1 to size, | \n"
+ "\t-r -g half gaussian random from 1 with 2.5 sigma size., | \n"
+ "\t-r -c <file> use cdf from file, size is a scale factor.,] \n"
+ "\t-x random seed\n");
fflush(stderr);
}
@@ -368,28 +370,36 @@ int main(int argc, char *argv[]) {
/* Handle the command-line, we expect the number of messages to exchange per
* rank an output log and some options, the interesting ones are a size and
- * whether to use a random selection (with a fixed seed). */
+ * whether to use a random selections of various kinds. */
int size = 1024;
int random = 0;
int uniform = 1;
+ char *cdf = NULL;
int opt;
- while ((opt = getopt(argc, argv, "vds:rg")) != -1) {
+ unsigned int seed = default_seed;
+ while ((opt = getopt(argc, argv, "vds:rgx:c:")) != -1) {
switch (opt) {
case 'd':
datacheck = 1;
break;
+ case 'c':
+ cdf = optarg;
+ break;
+ case 'g':
+ uniform = 0;
+ break;
case 's':
size = atoi(optarg);
break;
case 'r':
random = 1;
break;
- case 'g':
- uniform = 0;
- break;
case 'v':
verbose = 1;
break;
+ case 'x':
+ seed = atol(optarg);
+ break;
default:
if (myrank == 0) usage(argv);
return 1;
@@ -408,7 +418,12 @@ int main(int argc, char *argv[]) {
/* Generate the fake logs for the exchanges. */
if (myrank == 0) {
if (random) {
- if (uniform) {
+ if (cdf != NULL) {
+ message("Generating %d fake logs for %d ranks with randoms"
+ " based on cdf %s scaled by factor %d", nr_logs, nr_nodes,
+ cdf,size);
+
+ } else if (uniform) {
message("Generating %d fake logs for %d ranks with random distribution"
" using size %d", nr_logs, nr_nodes, size);
} else {
@@ -420,7 +435,7 @@ int main(int argc, char *argv[]) {
nr_logs, nr_nodes, size);
}
}
- mpiuse_log_generate(nr_nodes, nr_logs, size, random, seed, uniform);
+ mpiuse_log_generate(nr_nodes, nr_logs, size, random, seed, uniform, cdf);
int nranks = mpiuse_nr_ranks();
/* Each rank requires its own queue, so extract them. */