minix/tests/testcache.c

   1 /* A general i/o consistency test library. It performs i/o
   2  * using functions provided by the client (readblock, dowriteblock)
   3  * with a working set size specified by the client. It checks that
   4  * blocks that were written have the same contents when later read,
   5  * using different access patterns. The assumption is the various
   6  * cache layers so exercised are forced into many different states
   7  * (reordering, eviction, etc), hopefully triggering bugs if present.
   8  *
   9  * Entry point: dotest()
  10  */
  11
  12 #include <sys/types.h>
  13 #include <sys/ioc_memory.h>
  14 #include <stdio.h>
  15 #include <assert.h>
  16 #include <string.h>
  17 #include <stdlib.h>
  18 #include <unistd.h>
  19 #include <fcntl.h>
  20
  21 #include "testcache.h"
  22 #include "common.h"
  23
  24 extern int quietflag;
  25
  26 int fds[MAXFILES];
  27
  28 static void
  29 genblock(int b, char *blockdata, int blocksize, u32_t seed)
  30 {
  31         u32_t *p = (u32_t *) blockdata,
  32                 *plimit = (u32_t *) (blockdata + blocksize),
  33                 i = 0;
  34
  35         srandom(seed ^ b);
  36
  37         for(p = (u32_t *) blockdata; p < plimit; p++) {
  38                 i++;
  39                 *p = random();
  40         }
  41 }
  42
  43 static int
  44 checkblock(int b, int blocksize, u32_t seed)
  45 {
  46         static char data[MAXBLOCKSIZE], expected_data[MAXBLOCKSIZE];
  47         int r;
  48
  49         genblock(b, expected_data, blocksize, seed);
  50
  51         r = readblock(b, blocksize, seed, data);
  52
  53         if(r == OK_BLOCK_GONE) { return 0; }
  54
  55         if(r != blocksize) {
  56                 fprintf(stderr, "readblock failed\n");
  57                 return 1;
  58         }
  59
  60         if(memcmp(expected_data, data, blocksize)) {
  61                 fprintf(stderr, "comparison of %d failed\n", b);
  62                 return 1;
  63         }
  64
  65         return 0;
  66 }
  67
  68 static int
  69 writeblock(int b, int blocksize, u32_t seed)
  70 {
  71         static char data[MAXBLOCKSIZE];
  72
  73         genblock(b, data, blocksize, seed);
  74
  75         if(dowriteblock(b, blocksize, seed, data) != blocksize) {
  76                 fprintf(stderr, "writeblock of %d failed\n", b);
  77                 return 0;
  78         }
  79
  80         return blocksize;
  81 }
  82
  83 static int *
  84 makepermutation(int nblocks, int *permutation)
  85 {
  86         int b;
  87
  88         assert(nblocks > 0 && nblocks <= MAXBLOCKS);
  89
  90         for(b = 0; b < nblocks; b++) permutation[b] = b;
  91
  92         for(b = 0; b < nblocks-1; b++) {
  93                 int s, other = b + random() % (nblocks - b - 1);
  94                 assert(other >= b && other < nblocks);
  95                 s = permutation[other];
  96                 permutation[other] = permutation[b];
  97                 permutation[b] = s;
  98         }
  99
 100         return permutation;
 101 }
 102
 103 static int
 104 checkblocks(int nblocks, int blocksize, u32_t seed)
 105 {
 106         int b;
 107         int nrandom = nblocks * 3;
 108         static int perm1[MAXBLOCKS];
 109
 110         if(!quietflag) { fprintf(stderr, "\nverifying "); fflush(stderr); }
 111
 112         makepermutation(nblocks, perm1);
 113
 114         assert(nblocks > 0 && nblocks <= MAXBLOCKS);
 115         assert(blocksize > 0 && blocksize <= MAXBLOCKSIZE);
 116
 117         for(b = 0; b < nblocks; b++) {
 118                 if(checkblock(b, blocksize, seed)) { return 1; }
 119         }
 120
 121         for(b = 0; b < nrandom; b++) {
 122                 if(checkblock(random() % nblocks, blocksize, seed)) { return 1; }
 123         }
 124
 125         for(b = 0; b < nblocks; b++) {
 126                 if(checkblock(b, blocksize, seed)) { return 1; }
 127         }
 128
 129         for(b = 0; b < nblocks; b++) {
 130                 if(checkblock(perm1[b], blocksize, seed)) { return 1; }
 131         }
 132
 133         if(!quietflag) { fprintf(stderr, "done\n"); }
 134
 135         return 0;
 136 }
 137
 138 int
 139 dotest(int blocksize, int nblocks, int iterations)
 140 {
 141         int b, i;
 142         int nrandom = nblocks * iterations;
 143         static int perm1[MAXBLOCKS], perm2[MAXBLOCKS];
 144         static int newblock[MAXBLOCKS];
 145         u32_t seed = random(), newseed;
 146         int mb;
 147
 148         assert(nblocks > 0 && nblocks <= MAXBLOCKS);
 149
 150         mb = (int) ((u64_t) blocksize * nblocks / 1024 / 1024);
 151
 152         if(!quietflag) { fprintf(stderr, "test: %d * %d = %dMB\n", blocksize, nblocks, mb); }
 153
 154         for(b = 0; b < nblocks; b++) {
 155                 if(writeblock(b, blocksize, seed) < blocksize) { return 1; }
 156                 if(checkblock(b, blocksize, seed)) { return 1; }
 157                 printprogress("writing sequential", b, nblocks);
 158         }
 159
 160         if(checkblocks(nblocks, blocksize, seed)) { return 1; }
 161
 162         makepermutation(nblocks, perm1);
 163
 164         for(b = 0; b < nblocks; b++) {
 165                 if(writeblock(perm1[b], blocksize, seed) < blocksize) { return 1; }
 166                 if(checkblock(perm1[b], blocksize, seed)) { return 1; }
 167                 printprogress("writing permutation", b, nblocks);
 168         }
 169
 170         if(checkblocks(nblocks, blocksize, seed)) { return 1; }
 171
 172         for(i = 0; i < iterations; i++) {
 173                 makepermutation(nblocks, perm1);
 174                 makepermutation(nblocks, perm2);
 175                 memset(newblock, 0, sizeof(newblock));
 176
 177                 newseed = random();
 178
 179                 if(!quietflag) { fprintf(stderr, "iteration %d/%d\n", i, iterations); }
 180
 181                 for(b = 0; b < nblocks; b++) {
 182                         int wr = perm1[b], check = perm2[b];
 183                         if(writeblock(wr, blocksize, newseed) < blocksize) { return 1; }
 184                         newblock[wr] = 1;
 185                         if(checkblock(check, blocksize, newblock[check] ? newseed : seed)) { return 1; }
 186                         printprogress("interleaved permutation read, write", b, nblocks);
 187                 }
 188
 189                 seed = newseed;
 190
 191                 if(checkblocks(nblocks, blocksize, seed)) { return 1; }
 192         }
 193
 194         newseed = random();
 195
 196         memset(newblock, 0, sizeof(newblock));
 197
 198         for(b = 0; b < nrandom; b++) {
 199                 int wr = random() % nblocks, check = random() % nblocks;
 200                 if(writeblock(wr, blocksize, newseed) < blocksize) { return 1; }
 201                 newblock[wr] = 1;
 202                 if(checkblock(check, blocksize,
 203                         newblock[check] ? newseed : seed)) { return 1; }
 204                 printprogress("1 random verify, 1 random write", b, nrandom);
 205         }
 206
 207         seed = newseed;
 208
 209         if(!quietflag) { fprintf(stderr, "\n"); }
 210         testend();
 211
 212         return 0;
 213 }
 214
 215 void
 216 get_fd_offset(int b, int blocksize, u64_t *file_offset, int *fd)
 217 {
 218         u64_t offset = (u64_t) b * blocksize;
 219         int filenumber;
 220
 221         filenumber = offset / MB / MBPERFILE;
 222
 223         assert(filenumber >= 0 && filenumber < MAXFILES);
 224         assert(fds[filenumber] > 0);
 225
 226         *fd = fds[filenumber];
 227         *file_offset = offset - (filenumber * MBPERFILE * MB);
 228 }
 229
 230 void
 231 makefiles(int n)
 232 {
 233         int f;
 234         for(f = 0; f < n; f++) {
 235                 char tempfilename[] = "cachetest.XXXXXXXX";
 236                 fds[f] = mkstemp(tempfilename);
 237                 if(fds[f] < 0) {
 238                         perror("mkstemp");
 239                         fprintf(stderr, "mkstemp %d/%d failed\n", f, n);
 240                         exit(1);
 241                 }
 242                 assert(fds[f] > 0);
 243         }
 244 }
 245
 246 void cachequiet(int quiet)
 247 {
 248         quietflag = quiet;
 249 }
 250