xref: /redis-3.2.3/src/memtest.c (revision fc00042e)
1 /*
2  * Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  *
8  *   * Redistributions of source code must retain the above copyright notice,
9  *     this list of conditions and the following disclaimer.
10  *   * Redistributions in binary form must reproduce the above copyright
11  *     notice, this list of conditions and the following disclaimer in the
12  *     documentation and/or other materials provided with the distribution.
13  *   * Neither the name of Redis nor the names of its contributors may be used
14  *     to endorse or promote products derived from this software without
15  *     specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
21  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  */
29 #include <stdint.h>
30 #include <stdlib.h>
31 #include <stdio.h>
32 #include <string.h>
33 #include <assert.h>
34 #include <limits.h>
35 #include <errno.h>
36 #include <termios.h>
37 #include <sys/ioctl.h>
38 #if defined(__sun)
39 #include <stropts.h>
40 #endif
41 #include "config.h"
42 
43 #if (ULONG_MAX == 4294967295UL)
44 #define MEMTEST_32BIT
45 #elif (ULONG_MAX == 18446744073709551615ULL)
46 #define MEMTEST_64BIT
47 #else
48 #error "ULONG_MAX value not supported."
49 #endif
50 
51 #ifdef MEMTEST_32BIT
52 #define ULONG_ONEZERO 0xaaaaaaaaUL
53 #define ULONG_ZEROONE 0x55555555UL
54 #else
55 #define ULONG_ONEZERO 0xaaaaaaaaaaaaaaaaUL
56 #define ULONG_ZEROONE 0x5555555555555555UL
57 #endif
58 
59 static struct winsize ws;
60 size_t progress_printed; /* Printed chars in screen-wide progress bar. */
61 size_t progress_full; /* How many chars to write to fill the progress bar. */
62 
memtest_progress_start(char * title,int pass)63 void memtest_progress_start(char *title, int pass) {
64     int j;
65 
66     printf("\x1b[H\x1b[2J");    /* Cursor home, clear screen. */
67     /* Fill with dots. */
68     for (j = 0; j < ws.ws_col*(ws.ws_row-2); j++) printf(".");
69     printf("Please keep the test running several minutes per GB of memory.\n");
70     printf("Also check http://www.memtest86.com/ and http://pyropus.ca/software/memtester/");
71     printf("\x1b[H\x1b[2K");          /* Cursor home, clear current line.  */
72     printf("%s [%d]\n", title, pass); /* Print title. */
73     progress_printed = 0;
74     progress_full = ws.ws_col*(ws.ws_row-3);
75     fflush(stdout);
76 }
77 
memtest_progress_end(void)78 void memtest_progress_end(void) {
79     printf("\x1b[H\x1b[2J");    /* Cursor home, clear screen. */
80 }
81 
memtest_progress_step(size_t curr,size_t size,char c)82 void memtest_progress_step(size_t curr, size_t size, char c) {
83     size_t chars = ((unsigned long long)curr*progress_full)/size, j;
84 
85     for (j = 0; j < chars-progress_printed; j++) printf("%c",c);
86     progress_printed = chars;
87     fflush(stdout);
88 }
89 
90 /* Test that addressing is fine. Every location is populated with its own
91  * address, and finally verified. This test is very fast but may detect
92  * ASAP big issues with the memory subsystem. */
memtest_addressing(unsigned long * l,size_t bytes,int interactive)93 int memtest_addressing(unsigned long *l, size_t bytes, int interactive) {
94     unsigned long words = bytes/sizeof(unsigned long);
95     unsigned long j, *p;
96 
97     /* Fill */
98     p = l;
99     for (j = 0; j < words; j++) {
100         *p = (unsigned long)p;
101         p++;
102         if ((j & 0xffff) == 0 && interactive)
103             memtest_progress_step(j,words*2,'A');
104     }
105     /* Test */
106     p = l;
107     for (j = 0; j < words; j++) {
108         if (*p != (unsigned long)p) {
109             if (interactive) {
110                 printf("\n*** MEMORY ADDRESSING ERROR: %p contains %lu\n",
111                     (void*) p, *p);
112                 exit(1);
113             }
114             return 1;
115         }
116         p++;
117         if ((j & 0xffff) == 0 && interactive)
118             memtest_progress_step(j+words,words*2,'A');
119     }
120     return 0;
121 }
122 
123 /* Fill words stepping a single page at every write, so we continue to
124  * touch all the pages in the smallest amount of time reducing the
125  * effectiveness of caches, and making it hard for the OS to transfer
126  * pages on the swap.
127  *
128  * In this test we can't call rand() since the system may be completely
129  * unable to handle library calls, so we have to resort to our own
130  * PRNG that only uses local state. We use an xorshift* PRNG. */
131 #define xorshift64star_next() do { \
132         rseed ^= rseed >> 12; \
133         rseed ^= rseed << 25; \
134         rseed ^= rseed >> 27; \
135         rout = rseed * UINT64_C(2685821657736338717); \
136 } while(0)
137 
memtest_fill_random(unsigned long * l,size_t bytes,int interactive)138 void memtest_fill_random(unsigned long *l, size_t bytes, int interactive) {
139     unsigned long step = 4096/sizeof(unsigned long);
140     unsigned long words = bytes/sizeof(unsigned long)/2;
141     unsigned long iwords = words/step;  /* words per iteration */
142     unsigned long off, w, *l1, *l2;
143     uint64_t rseed = UINT64_C(0xd13133de9afdb566); /* Just a random seed. */
144     uint64_t rout = 0;
145 
146     assert((bytes & 4095) == 0);
147     for (off = 0; off < step; off++) {
148         l1 = l+off;
149         l2 = l1+words;
150         for (w = 0; w < iwords; w++) {
151             xorshift64star_next();
152             *l1 = *l2 = (unsigned long) rout;
153             l1 += step;
154             l2 += step;
155             if ((w & 0xffff) == 0 && interactive)
156                 memtest_progress_step(w+iwords*off,words,'R');
157         }
158     }
159 }
160 
161 /* Like memtest_fill_random() but uses the two specified values to fill
162  * memory, in an alternated way (v1|v2|v1|v2|...) */
memtest_fill_value(unsigned long * l,size_t bytes,unsigned long v1,unsigned long v2,char sym,int interactive)163 void memtest_fill_value(unsigned long *l, size_t bytes, unsigned long v1,
164                         unsigned long v2, char sym, int interactive)
165 {
166     unsigned long step = 4096/sizeof(unsigned long);
167     unsigned long words = bytes/sizeof(unsigned long)/2;
168     unsigned long iwords = words/step;  /* words per iteration */
169     unsigned long off, w, *l1, *l2, v;
170 
171     assert((bytes & 4095) == 0);
172     for (off = 0; off < step; off++) {
173         l1 = l+off;
174         l2 = l1+words;
175         v = (off & 1) ? v2 : v1;
176         for (w = 0; w < iwords; w++) {
177 #ifdef MEMTEST_32BIT
178             *l1 = *l2 = ((unsigned long)     v) |
179                         (((unsigned long)    v) << 16);
180 #else
181             *l1 = *l2 = ((unsigned long)     v) |
182                         (((unsigned long)    v) << 16) |
183                         (((unsigned long)    v) << 32) |
184                         (((unsigned long)    v) << 48);
185 #endif
186             l1 += step;
187             l2 += step;
188             if ((w & 0xffff) == 0 && interactive)
189                 memtest_progress_step(w+iwords*off,words,sym);
190         }
191     }
192 }
193 
memtest_compare(unsigned long * l,size_t bytes,int interactive)194 int memtest_compare(unsigned long *l, size_t bytes, int interactive) {
195     unsigned long words = bytes/sizeof(unsigned long)/2;
196     unsigned long w, *l1, *l2;
197 
198     assert((bytes & 4095) == 0);
199     l1 = l;
200     l2 = l1+words;
201     for (w = 0; w < words; w++) {
202         if (*l1 != *l2) {
203             if (interactive) {
204                 printf("\n*** MEMORY ERROR DETECTED: %p != %p (%lu vs %lu)\n",
205                     (void*)l1, (void*)l2, *l1, *l2);
206                 exit(1);
207             }
208             return 1;
209         }
210         l1 ++;
211         l2 ++;
212         if ((w & 0xffff) == 0 && interactive)
213             memtest_progress_step(w,words,'=');
214     }
215     return 0;
216 }
217 
memtest_compare_times(unsigned long * m,size_t bytes,int pass,int times,int interactive)218 int memtest_compare_times(unsigned long *m, size_t bytes, int pass, int times,
219                           int interactive)
220 {
221     int j;
222     int errors = 0;
223 
224     for (j = 0; j < times; j++) {
225         if (interactive) memtest_progress_start("Compare",pass);
226         errors += memtest_compare(m,bytes,interactive);
227         if (interactive) memtest_progress_end();
228     }
229     return errors;
230 }
231 
232 /* Test the specified memory. The number of bytes must be multiple of 4096.
233  * If interactive is true the program exists with an error and prints
234  * ASCII arts to show progresses. Instead when interactive is 0, it can
235  * be used as an API call, and returns 1 if memory errors were found or
236  * 0 if there were no errors detected. */
memtest_test(unsigned long * m,size_t bytes,int passes,int interactive)237 int memtest_test(unsigned long *m, size_t bytes, int passes, int interactive) {
238     int pass = 0;
239     int errors = 0;
240 
241     while (pass != passes) {
242         pass++;
243 
244         if (interactive) memtest_progress_start("Addressing test",pass);
245         errors += memtest_addressing(m,bytes,interactive);
246         if (interactive) memtest_progress_end();
247 
248         if (interactive) memtest_progress_start("Random fill",pass);
249         memtest_fill_random(m,bytes,interactive);
250         if (interactive) memtest_progress_end();
251         errors += memtest_compare_times(m,bytes,pass,4,interactive);
252 
253         if (interactive) memtest_progress_start("Solid fill",pass);
254         memtest_fill_value(m,bytes,0,(unsigned long)-1,'S',interactive);
255         if (interactive) memtest_progress_end();
256         errors += memtest_compare_times(m,bytes,pass,4,interactive);
257 
258         if (interactive) memtest_progress_start("Checkerboard fill",pass);
259         memtest_fill_value(m,bytes,ULONG_ONEZERO,ULONG_ZEROONE,'C',interactive);
260         if (interactive) memtest_progress_end();
261         errors += memtest_compare_times(m,bytes,pass,4,interactive);
262     }
263     return errors;
264 }
265 
266 /* A version of memtest_test() that tests memory in small pieces
267  * in order to restore the memory content at exit.
268  *
269  * One problem we have with this approach, is that the cache can avoid
270  * real memory accesses, and we can't test big chunks of memory at the
271  * same time, because we need to backup them on the stack (the allocator
272  * may not be usable or we may be already in an out of memory condition).
273  * So what we do is to try to trash the cache with useless memory accesses
274  * between the fill and compare cycles. */
275 #define MEMTEST_BACKUP_WORDS (1024*(1024/sizeof(long)))
276 /* Random accesses of MEMTEST_DECACHE_SIZE are performed at the start and
277  * end of the region between fill and compare cycles in order to trash
278  * the cache. */
279 #define MEMTEST_DECACHE_SIZE (1024*8)
memtest_preserving_test(unsigned long * m,size_t bytes,int passes)280 int memtest_preserving_test(unsigned long *m, size_t bytes, int passes) {
281     unsigned long backup[MEMTEST_BACKUP_WORDS];
282     unsigned long *p = m;
283     unsigned long *end = (unsigned long*) (((unsigned char*)m)+(bytes-MEMTEST_DECACHE_SIZE));
284     size_t left = bytes;
285     int errors = 0;
286 
287     if (bytes & 4095) return 0; /* Can't test across 4k page boundaries. */
288     if (bytes < 4096*2) return 0; /* Can't test a single page. */
289 
290     while(left) {
291         /* If we have to test a single final page, go back a single page
292          * so that we can test two pages, since the code can't test a single
293          * page but at least two. */
294         if (left == 4096) {
295             left += 4096;
296             p -= 4096/sizeof(unsigned long);
297         }
298 
299         int pass = 0;
300         size_t len = (left > sizeof(backup)) ? sizeof(backup) : left;
301 
302         /* Always test an even number of pages. */
303         if (len/4096 % 2) len -= 4096;
304 
305         memcpy(backup,p,len); /* Backup. */
306         while(pass != passes) {
307             pass++;
308             errors += memtest_addressing(p,len,0);
309             memtest_fill_random(p,len,0);
310             if (bytes >= MEMTEST_DECACHE_SIZE) {
311                 memtest_compare_times(m,MEMTEST_DECACHE_SIZE,pass,1,0);
312                 memtest_compare_times(end,MEMTEST_DECACHE_SIZE,pass,1,0);
313             }
314             errors += memtest_compare_times(p,len,pass,4,0);
315             memtest_fill_value(p,len,0,(unsigned long)-1,'S',0);
316             if (bytes >= MEMTEST_DECACHE_SIZE) {
317                 memtest_compare_times(m,MEMTEST_DECACHE_SIZE,pass,1,0);
318                 memtest_compare_times(end,MEMTEST_DECACHE_SIZE,pass,1,0);
319             }
320             errors += memtest_compare_times(p,len,pass,4,0);
321             memtest_fill_value(p,len,ULONG_ONEZERO,ULONG_ZEROONE,'C',0);
322             if (bytes >= MEMTEST_DECACHE_SIZE) {
323                 memtest_compare_times(m,MEMTEST_DECACHE_SIZE,pass,1,0);
324                 memtest_compare_times(end,MEMTEST_DECACHE_SIZE,pass,1,0);
325             }
326             errors += memtest_compare_times(p,len,pass,4,0);
327         }
328         memcpy(p,backup,len); /* Restore. */
329         left -= len;
330         p += len/sizeof(unsigned long);
331     }
332     return errors;
333 }
334 
335 /* Perform an interactive test allocating the specified number of megabytes. */
memtest_alloc_and_test(size_t megabytes,int passes)336 void memtest_alloc_and_test(size_t megabytes, int passes) {
337     size_t bytes = megabytes*1024*1024;
338     unsigned long *m = malloc(bytes);
339 
340     if (m == NULL) {
341         fprintf(stderr,"Unable to allocate %zu megabytes: %s",
342             megabytes, strerror(errno));
343         exit(1);
344     }
345     memtest_test(m,bytes,passes,1);
346     free(m);
347 }
348 
memtest(size_t megabytes,int passes)349 void memtest(size_t megabytes, int passes) {
350     if (ioctl(1, TIOCGWINSZ, &ws) == -1) {
351         ws.ws_col = 80;
352         ws.ws_row = 20;
353     }
354     memtest_alloc_and_test(megabytes,passes);
355     printf("\nYour memory passed this test.\n");
356     printf("Please if you are still in doubt use the following two tools:\n");
357     printf("1) memtest86: http://www.memtest86.com/\n");
358     printf("2) memtester: http://pyropus.ca/software/memtester/\n");
359     exit(0);
360 }
361