added new tool

utils/CMakeLists.txt

@@ -4,6 +4,8 @@ project (stutools)
 set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g -Werror -Wall -pedantic --std=c99 -O2" )
 #SET (CMAKE_C_COMPILER             "/usr/bin/clang")
 
+add_executable(stripesim stripesim.c)
+
 add_executable(median median.c)
 
 add_executable(dist dist.c)

utils/stripesim.c

@@ -0,0 +1,221 @@
+#define _XOPEN_SOURCE 500
+
+#include <stdio.h>
+#include <time.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <assert.h>
+#include <string.h>
+
+void usage() {
+  printf("usage: stripsim -g 2 -d 13 -k 6 -m 3 -T 20 -s 1\n");
+  printf("\n");
+  printf("options:\n");
+  printf("   -g n    groups of drives\n");
+  printf("   -d n    drives per group (total = g x d)\n");
+  printf("   -k/m    data/parity\n");
+  printf("   -T      size of drive in TB\n");
+  printf("   -s      stripe size in MB\n");
+  printf("   -H      print histogram\n");
+  printf("   -H -H   verbose histogram\n");
+  printf("   -f 0,2... list of failed drives\n");
+}
+
+
+int simulate(int *drivesok, int groups, int drives, int k, int m, int T, int s, int Print, int showhist) {
+  size_t totaldrives = groups * drives;
+  size_t totalrows = T*1000L*1000L / s;
+
+  //  printf("*info* total = %zd\n", totalrows * totaldrives);
+
+  unsigned int *a = calloc(totaldrives * totalrows, sizeof(unsigned int));
+  if (!a) {
+    printf("OOM!, trying to allocate %zd \n", totaldrives * totalrows * sizeof(int));
+    exit(1);
+  }
+
+  int *stripecounter = calloc(totaldrives, sizeof(int));
+  int *shuf = calloc(drives, sizeof(int));
+
+
+  int maxstrips = T*1000*1000/(s*(k+m));
+  //  printf("max strips %d\n", maxstrips);
+  int stripid = 0;
+
+  int stripe = 0;
+  for (stripe = 0; stripe < maxstrips; stripe++) {
+
+    for (int g = 0; g < groups; g++) {
+      // setup
+      for (int d = 0; d < drives; d++) {
+	shuf[d] = g * drives + d;
+      }
+      // shuffle
+      for (int d = 0; d < drives; d++) {
+	int i = d;
+	int j = drand48() * drives;
+
+	int temp = shuf[i];
+	shuf[i] = shuf[j];
+	shuf[j] = temp;
+	//	printf("drive %d\n", shuf[d]);
+      }
+      stripid++;
+      for (int d = 0; d < k+m; d++) {
+
+	//	printf("%d %zd\n", shuf[d], shuf[d]*totaldrives);
+	int ii = stripecounter[shuf[d]] * totaldrives + shuf[d];
+	assert(ii >= 0);
+	if (ii < totalrows * totaldrives) {
+	  a[ii] = stripid; //stripecounter[shuf[d]];
+
+	  stripecounter[shuf[d]]++;
+	} else {
+	  printf("breaking out!\n");
+	  break;
+	}
+
+      }
+    }
+
+
+    //    printf("---");
+    //    for (int i = 0; i < totaldrives; i++) {
+    //      printf("%d ",stripecounter[i]);
+    //    }
+    //    printf("\n");
+  }
+
+
+  // histogram
+  if (showhist) {
+    printf("maximum stripid %d\n", stripid);
+    int *striphist = calloc(stripid, sizeof(int));
+    for (int r = 0 ; r < totalrows; r++) {
+      for (int g = 0; g < groups; g++ ){
+	for (int i = 0; i < drives; i++) {
+	  int driveid = g * drives + i;
+	  if (drivesok[driveid]) 
+	    {
+	      int v = a[r * totaldrives + driveid];
+	      assert(v>=0);
+	      //	      assert(v < stripid);
+	      //	      printf("v = %d, max = %d\n", v, stripid);
+	      if (v < stripid) {
+		striphist[v]++;
+	      }
+	    }
+
+	}
+      }
+    }
+
+    int *histhist = calloc(k+m+1, sizeof(int));
+    assert(histhist);
+
+    for (int i = 1; i < stripid; i++) {
+      if (striphist[i]) {
+	histhist[striphist[i]]++;
+	if (striphist[i] < k+m) {
+	  if (showhist >= 2) printf("strip %d = %d %s\n", i, striphist[i], striphist[i] < k ? "ERROR":"");
+	  if (striphist[i] < k)
+	    exit(1);
+	}
+      }
+    }
+    printf("\n");
+    for (int i = 1; i <= k+m; i++) {
+      printf("drives %d = %d\n", i, histhist[i]);
+    }
+    free(histhist);
+  } else {
+
+    for (int stripe = 0 ; stripe < Print; stripe++) {
+      for (int g = 0; g < groups; g++ ){
+	printf("| ");
+	for (int i = 0; i < drives; i++) {
+	  printf("%3d ", (int)a[stripe * totaldrives + (g*drives+i)]);
+	}
+      }
+      printf("\n");
+    }
+  }
+
+  free(shuf);
+  free(stripecounter);
+  free(a);
+  return 0;
+}
+
+
+
+int main(int argc, char *argv[]) {
+
+  srand48(time(NULL));
+
+
+  const char *getoptstring = "hg:d:k:m:T:s:p:Hf:";
+
+  int opt;
+  int groups = 2;
+  int drives = 13;
+  int k = 6;
+  int m = 3;
+  int T = 1;
+  int s = 1;
+  int Print = 100;
+  int showhist = 0;
+  char *failed = NULL;
+
+  while
+    ((opt = getopt(argc, argv, getoptstring)) != -1) {
+    switch (opt) {
+    case 'h':
+      usage();
+      exit(1);
+    case 'g': groups = atoi(optarg);break;
+    case 'd': drives = atoi(optarg);break;
+    case 'k': k = atoi(optarg);break;
+    case 'm': m = atoi(optarg);break;
+    case 'T': T = atoi(optarg);break;
+    case 's': s = atoi(optarg);break;
+    case 'p': Print = atoi(optarg); break;
+    case 'H': showhist++; break;
+    case 'f': failed = strdup(optarg); break;
+    default:
+      usage();
+      exit(1);
+    }
+  }
+
+  if (k+m > drives) {
+    printf("*error* you can't have less drives than k+m\n");
+    exit(1);
+  }
+
+  printf("*info* groups %d, drives/group %d, %d+%d, drive %d TB, stripe %d MB, failed '%s'\n", groups, drives, k, m, T, s, failed ? failed : "");
+
+
+  int *drivesok = calloc(drives * groups, sizeof(int));
+  for (int i = 0; i < drives * groups; i++) {
+    drivesok[i] = 1;
+  }
+  if (failed) {
+    char *first = strtok(failed, ",");
+    while (first) {
+      //      printf("%d\n", atoi(first));
+      if (atoi(first) >= drives*groups) {
+	printf("Error, can't be >= %d\n", drives*groups);
+	exit(1);
+      }
+      drivesok[atoi(first)] = 0;
+      first = strtok(NULL, ",");
+    }
+  }
+
+  simulate(drivesok, groups, drives, k, m, T, s, Print, showhist);
+
+
+  return 0;
+}