Create branch with fake data generation

Makefile

 CFLAGS = -g -O0 -Wall
 
-all: swiftmpistepsim
+all: swiftmpistepsim swiftmpifakestepsim
 
 swiftmpistepsim: swiftmpistepsim.c mpiuse.c mpiuse.h atomic.h cycle.h clocks.h clocks.c
 	mpicc $(CFLAGS) -o swiftmpistepsim swiftmpistepsim.c mpiuse.c clocks.c
 
+swiftmpifakestepsim: swiftmpifakestepsim.c mpiuse.c mpiuse.h atomic.h cycle.h clocks.h clocks.c
+	mpicc $(CFLAGS) -o swiftmpifakestepsim swiftmpifakestepsim.c mpiuse.c clocks.c
+
 clean:
 	rm -f swiftmpistepsim
+	rm -f swiftmpifakestepsim

mpiuse.c

@@ -210,7 +210,7 @@ void mpiuse_dump_logs(int nranks, const char *dumpfile) {
       ticks basetics = 0;
       for (size_t k = 0; k < nlogs; k++) {
         struct mpiuse_log_entry *log = &mpiuse_log[k];
-        if (log->rank == myrank && log->endtic > 0) {
+        if (log->rank == myrank) {
           if (basetics == 0) basetics = log->tic;
           fprintf(fd,
                   "%lld %.4f %.4f %.4f %.6f %d %d %d %d %d %d %zd %d %.4f %.6f "
@@ -257,3 +257,27 @@ struct mpiuse_log_entry *mpiuse_get_log(int ind) {
   if (ind < mpiuse_log_count && ind >= 0) return &mpiuse_log[ind];
   return NULL;
 }
+
+/**
+ * @brief generate a list of fake exchanges as mpiuse logs.
+ *
+ * @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
+ */
+void mpiuse_log_generate(int nr_nodes, int nr_logs, int size) {
+
+  /* Each rank exchange messages with all the others with a fixed size. */
+  int tag = 1;
+  for (int k = 0; k < nr_logs; k++) {
+    for (int i = 0; i < nr_nodes; i++) {
+      for (int j = 0; j < nr_nodes; j++) {
+        if (i != j) {
+          mpiuse_log_allocation(i, 1, k, SEND_TYPE, NO_SUBTYPE, 1, size, j, tag);
+          mpiuse_log_allocation(j, 1, k, RECV_TYPE, NO_SUBTYPE, 1, size, i, tag);
+        }
+      }
+    }
+    tag++;
+  }
+}

mpiuse.h

@@ -84,6 +84,13 @@ struct mpiuse_log_entry {
   ticks tmin;
 };
 
+/* Flags for the types of request when generating fakes. */
+#ifndef SEND_TYPE
+#define SEND_TYPE 22
+#define RECV_TYPE 23
+#define NO_SUBTYPE 0
+#endif
+
 /* API. */
 void mpiuse_log_allocation(int rank, int step, size_t tic, int type,
                            int subtype, int activation, size_t size,
@@ -94,4 +101,6 @@ int mpiuse_nr_logs(void);
 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);
+
 #endif /* SWIFT_MPIUSE_H */

swiftmpifakestepsim.c

+/*******************************************************************************
+ * This file is part of SWIFT.
+ * Copyright (c) 2021 Peter W. Draper
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ ******************************************************************************/
+
+#include <limits.h>
+#include <mpi.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "atomic.h"
+#include "clocks.h"
+#include "error.h"
+#include "mpiuse.h"
+
+/* Global: Our rank for all to see. */
+int myrank = -1;
+
+/* Are we verbose. */
+static int verbose = 0;
+
+/* Set a data pattern and check we get this back, slow... */
+static int datacheck = 0;
+
+/* The local queues. */
+static struct mpiuse_log_entry **volatile reqs_queue;
+static int volatile ind_req = 0;
+static int volatile nr_reqs = 0;
+static int volatile injecting = 1;
+static struct mpiuse_log_entry **volatile recvs_queue;
+static int volatile nr_recvs = 0;
+static int volatile ind_recv = 0;
+static int volatile todo_recv = 0;
+static struct mpiuse_log_entry **volatile sends_queue;
+static int volatile nr_sends = 0;
+static int volatile ind_send = 0;
+static int volatile todo_send = 0;
+
+/**
+ * @brief fill a data area with a pattern that can be checked for changes.
+ *
+ * @param size size of data in bytes.
+ * @param data the data to fill.
+ */
+static void datacheck_fill(size_t size, void *data) {
+  unsigned char *p = (unsigned char *)data;
+  for (size_t i = 0; i < size; i++) {
+      p[i] = 170; /* 10101010 in bits. */
+  }
+}
+
+/**
+ * @brief test a filled data area for our pattern.
+ *
+ * @param size size of data in bytes.
+ * @param data the data to fill.
+ *
+ * @result 1 on success, 0 otherwise.
+ */
+static int datacheck_test(size_t size, void *data) {
+  unsigned char *p = (unsigned char *)data;
+  for (size_t i = 0; i < size; i++) {
+    if (p[i] != 170) return 0;
+  }
+  return 1;
+}
+
+/**
+ * @brief Injection thread, initiates MPI_Isend and MPI_Irecv requests.
+ */
+static void *inject_thread(void *arg) {
+
+  if (verbose) message("%d: injection thread starts", *((int *)arg));
+  ticks starttics = getticks();
+
+  while (ind_req < nr_reqs) {
+    struct mpiuse_log_entry *log = reqs_queue[ind_req];
+
+    /* Initialise new log elements. */
+    log->done = 0;
+    log->nr_tests = 0;
+    log->tsum = 0.0;
+    log->tmax = 0;
+    log->tmin = INT_MAX;
+    log->endtic = 0;
+    log->injtic = getticks();
+
+    /* Differences to SWIFT: MPI_BYTE not the MPI_Type. */
+    int err = 0;
+    if (log->type == SEND_TYPE) {
+      log->data = calloc(log->size, 1);
+
+      /* Fill data with pattern. */
+      if (datacheck) datacheck_fill(log->size, log->data);
+
+      /* And send. */
+      err = MPI_Isend(log->data, log->size, MPI_BYTE, log->otherrank, log->tag,
+                      MPI_COMM_WORLD, &log->req);
+
+      /* Add a new send request. */
+      int ind = atomic_inc(&nr_sends);
+      sends_queue[ind] = log;
+      atomic_inc(&todo_send);
+
+    } else {
+
+      /* Ready to receive. */
+      log->data = calloc(log->size, 1);
+      err = MPI_Irecv(log->data, log->size, MPI_BYTE, log->otherrank, log->tag,
+                      MPI_COMM_WORLD, &log->req);
+
+      /* Add a new recv request. */
+      int ind = atomic_inc(&nr_recvs);
+      recvs_queue[ind] = log;
+      atomic_inc(&todo_recv);
+    }
+    if (err != MPI_SUCCESS) error("Failed to activate send or recv");
+    
+    ind_req++;
+  }
+
+  /* All done, thread exiting. */
+  if (verbose) {
+    message("%d injections completed, sends = %d, recvs = %d", ind_req,
+            nr_sends, nr_recvs);
+    message("remaining sends = %d, recvs = %d", todo_send, todo_recv);
+  }
+  message("took %.3f %s.", clocks_from_ticks(getticks() - starttics),
+          clocks_getunit());
+  atomic_dec(&injecting);
+  return NULL;
+}
+
+/**
+ * @brief main loop to run over a queue of MPI requests and test for when they
+ * complete. Returns the total amount of time spent in calls to MPI_Test and
+ * the number of times it was called.
+ *
+ * @param logs the list of logs pointing to requests.
+ * @param nr_logs pointer to the variable containing the current number of
+ *                logs.
+ * @param todos pointer to the variable containing the number of requests that
+ *              are still active.
+ * @param sum the total number of ticks spent in calls to MPI_Test.
+ * @param ncalls the total number of calls to MPI_Test.
+ * @param mint the minimum ticks an MPI_Test call took.
+ * @param maxt the maximum ticks an MPI_Test call took.
+ */
+static void queue_runner(struct mpiuse_log_entry **logs, int volatile *nr_logs,
+                         int volatile *todos, double *sum, int *ncalls,
+                         ticks *mint, ticks *maxt) {
+
+  /* Global MPI_Test statistics. */
+  int lncalls = 0;
+  double lsum = 0.0;
+  ticks lmint = INT_MAX;
+  ticks lmaxt = 0;
+
+  /* We loop while new requests are being injected and we still have requests
+   * to complete. */
+  while (injecting || (!injecting && *todos > 0)) {
+    int nlogs = *nr_logs;
+    for (int k = 0; k < nlogs; k++) {
+      struct mpiuse_log_entry *log = logs[k];
+      if (log != NULL && !log->done) {
+        ticks tics = getticks();
+        int res;
+        MPI_Status stat;
+        int err = MPI_Test(&log->req, &res, &stat);
+        if (err != MPI_SUCCESS) {
+          error("MPI_Test call failed");
+        }
+
+        /* Increment etc. of statistics about time in MPI_Test. */
+        ticks dt = getticks() - tics;
+        log->tsum += (double)dt;
+        lsum += (double)dt;
+
+        log->nr_tests++;
+        lncalls++;
+
+        if (dt < log->tmin) log->tmin = dt;
+        if (dt > log->tmax) log->tmax = dt;
+        if (dt < lmint) lmint = dt;
+        if (dt > lmaxt) lmaxt = dt;
+
+        if (res) {
+          /* Check data sent data is unchanged and received data is as
+           * expected. */
+          if (datacheck && !datacheck_test(log->size, log->data)) {
+            error("Data mismatch on completion");
+          }
+
+          /* Done, clean up. */
+          log->done = 1;
+          log->endtic = getticks();
+          free(log->data);
+          atomic_dec(todos);
+        }
+      }
+    }
+  }
+
+  /* All done. */
+  *sum = lsum;
+  *ncalls = lncalls;
+  *mint = lmint;
+  *maxt = lmaxt;
+  return;
+}
+
+/**
+ * @brief Send thread, checks if MPI_Isend requests have completed.
+ */
+static void *send_thread(void *arg) {
+
+  if (verbose) message("%d: send thread starts (%d)", *((int *)arg),
+                       injecting);
+  ticks starttics = getticks();
+
+  int ncalls;
+  double sum;
+  ticks mint;
+  ticks maxt;
+  queue_runner(sends_queue, &nr_sends, &todo_send, &sum, &ncalls, &mint, &maxt);
+
+  message(
+      "%d MPI_Test calls took: %.3f, mean time %.3f, min time %.3f, max time "
+      "%.3f (%s)",
+      ncalls, clocks_from_ticks(sum), clocks_from_ticks(sum / ncalls),
+      clocks_from_ticks(mint), clocks_from_ticks(maxt), clocks_getunit());
+  if (verbose)
+    message("took %.3f %s.", clocks_from_ticks(getticks() - starttics),
+            clocks_getunit());
+
+  /* Thread exits. */
+  return NULL;
+}
+
+/**
+ * @brief Recv thread, checks if MPI_Irecv requests have completed.
+ */
+static void *recv_thread(void *arg) {
+
+  if (verbose) message("%d: recv thread starts", *((int *)arg));
+  ticks starttics = getticks();
+
+  int ncalls;
+  double sum;
+  ticks mint;
+  ticks maxt;
+  queue_runner(recvs_queue, &nr_recvs, &todo_recv, &sum, &ncalls, &mint, &maxt);
+
+  message(
+      "%d MPI_Test calls took: %.3f, mean time %.3f, min time %.3f, max time "
+      "%.3f (%s)",
+      ncalls, clocks_from_ticks(sum), clocks_from_ticks(sum / ncalls),
+      clocks_from_ticks(mint), clocks_from_ticks(maxt), clocks_getunit());
+  if (verbose)
+    message("took %.3f %s.", clocks_from_ticks(getticks() - starttics),
+            clocks_getunit());
+
+  /* Thread exits. */
+  return NULL;
+}
+
+/**
+ * @brief Comparison function for logged times.
+ */
+static int cmp_logs(const void *p1, const void *p2) {
+  struct mpiuse_log_entry *l1 = *(struct mpiuse_log_entry **)p1;
+  struct mpiuse_log_entry *l2 = *(struct mpiuse_log_entry **)p2;
+
+  /* Large unsigned values, so take care. */
+  if (l1->tic > l2->tic) return 1;
+  if (l1->tic < l2->tic) return -1;
+  return 0;
+}
+
+/**
+ * @brief Pick out the relevant logging data for our rank, i.e. all
+ * activations of sends and recvs. We ignore the original completions.
+ * The final list is sorted into increasing time of activation.
+ */
+static void pick_logs(void) {
+  size_t nlogs = mpiuse_nr_logs();
+
+  /* Duplicate of logs. */
+  reqs_queue = (struct mpiuse_log_entry **)calloc(
+      nlogs, sizeof(struct mpiuse_log_entry *));
+  nr_reqs = 0;
+  sends_queue = (struct mpiuse_log_entry **)calloc(
+      nlogs, sizeof(struct mpiuse_log_entry *));
+  nr_sends = 0;
+  recvs_queue = (struct mpiuse_log_entry **)calloc(
+      nlogs, sizeof(struct mpiuse_log_entry *));
+  nr_recvs = 0;
+
+  for (int k = 0; k < nlogs; k++) {
+    struct mpiuse_log_entry *log = mpiuse_get_log(k);
+    if (log->rank == myrank && log->activation) {
+      log->data = NULL;
+      reqs_queue[nr_reqs] = log;
+      nr_reqs++;
+    }
+  }
+
+  /* Sort into increasing time. */
+  qsort(reqs_queue, nr_reqs, sizeof(struct mpiuse_log_entry *), cmp_logs);
+
+  /* Check. */
+  for (int k = 0; k < nr_reqs - 1; k++) {
+    if (reqs_queue[k]->tic > reqs_queue[k + 1]->tic)
+      message("reqs_queue: %lld > %lld", reqs_queue[k]->tic,
+              reqs_queue[k + 1]->tic);
+  }
+}
+
+/**
+ * @brief usage help.
+ */
+static void usage(char *argv[]) {
+  fprintf(stderr, "Usage: %s [-vf] nr_messages logfile.dat\n",
+          argv[0]);
+  fprintf(stderr, " options: -v verbose, -d data check, -s size (bytes)\n");
+  fflush(stderr);
+}
+
+/**
+ * @brief main function.
+ */
+int main(int argc, char *argv[]) {
+
+  /* Initiate MPI. */
+  int prov = 0;
+  int res = MPI_Init_thread(&argc, &argv, MPI_THREAD_MULTIPLE, &prov);
+  if (res != MPI_SUCCESS)
+    error("Call to MPI_Init_thread failed with error %i.", res);
+
+  int nr_nodes = 0;
+  res = MPI_Comm_size(MPI_COMM_WORLD, &nr_nodes);
+  if (res != MPI_SUCCESS) error("MPI_Comm_size failed with error %i.", res);
+
+  res = MPI_Comm_rank(MPI_COMM_WORLD, &myrank);
+  if (res != MPI_SUCCESS)
+    error("Call to MPI_Comm_rank failed with error %i.", res);
+
+  /* Handle the command-line, we expect the number of messages to exchange per
+   * rank an output log and some options. */
+  int size = 1024;
+  int opt;
+  while ((opt = getopt(argc, argv, "vds:")) != -1) {
+    switch (opt) {
+      case 'd':
+        datacheck = 1;
+        break;
+      case 's':
+        size = atoi(optarg);
+        break;
+      case 'v':
+        verbose = 1;
+        break;
+      default:
+        if (myrank == 0) usage(argv);
+        return 1;
+    }
+  }
+  if (optind >= argc -1) {
+    if (myrank == 0) usage(argv);
+    return 1;
+  }
+
+  int nr_logs = atoi(argv[optind]);
+  if (nr_logs == 0)
+    error("Expected number of messages to exchange, got: %s", argv[optind]);
+  char *logfile = argv[optind + 1];
+
+  /* Generate the fake logs for the exchanges. */
+  if (myrank == 0) message("Generating %d fake logs for %d ranks of size %d",
+                           nr_logs, nr_nodes, size);
+  mpiuse_log_generate(nr_nodes, nr_logs, size);
+  int nranks = mpiuse_nr_ranks();
+
+  /* Each rank requires its own queue, so extract them. */
+  pick_logs();
+
+  /* Time to start time. Try to make it synchronous across the ranks. */
+  MPI_Barrier(MPI_COMM_WORLD);
+  clocks_set_cpufreq(0);
+  if (myrank == 0) {
+    message("Start of MPI tests");
+    message("==================");
+    if (verbose) {
+      if (datacheck) message("checking data pattern on send and recv completion");
+    }
+  }
+
+  /* Make three threads, one for injecting tasks and two to check for
+   * completions of the sends and recv independently. */
+  pthread_t injectthread;
+  if (pthread_create(&injectthread, NULL, &inject_thread, &myrank) != 0)
+    error("Failed to create injection thread.");
+  pthread_t sendthread;
+  if (pthread_create(&sendthread, NULL, &send_thread, &myrank) != 0)
+    error("Failed to create send thread.");
+  pthread_t recvthread;
+  if (pthread_create(&recvthread, NULL, &recv_thread, &myrank) != 0)
+    error("Failed to create recv thread.");
+
+  /* Wait until all threads have exited and all MPI requests have completed. */
+  pthread_join(injectthread, NULL);
+  pthread_join(sendthread, NULL);
+  pthread_join(recvthread, NULL);
+
+  /* Dump the updated MPI logs. */
+  MPI_Barrier(MPI_COMM_WORLD);
+  fflush(stdout);
+  if (myrank == 0) message("Dumping updated log");
+  mpiuse_dump_logs(nranks, logfile);
+
+  /* Shutdown MPI. */
+  res = MPI_Finalize();
+  if (res != MPI_SUCCESS)
+    error("call to MPI_Finalize failed with error %i.", res);
+
+  if (myrank == 0) message("Bye");
+
+  return 0;
+}