selftests/vm/transhuge-stress.c

0001 /*
0002  * Stress test for transparent huge pages, memory compaction and migration.
0003  *
0004  * Authors: Konstantin Khlebnikov <koct9i@gmail.com>
0005  *
0006  * This is free and unencumbered software released into the public domain.
0007  */
0008
0009 #include <stdlib.h>
0010 #include <stdio.h>
0011 #include <stdint.h>
0012 #include <err.h>
0013 #include <time.h>
0014 #include <unistd.h>
0015 #include <fcntl.h>
0016 #include <string.h>
0017 #include <sys/mman.h>
0018 #include "util.h"
0019
0020 int backing_fd = -1;
0021 int mmap_flags = MAP_ANONYMOUS | MAP_NORESERVE | MAP_PRIVATE;
0022 #define PROT_RW (PROT_READ | PROT_WRITE)
0023
0024 int main(int argc, char **argv)
0025 {
0026     size_t ram, len;
0027     void *ptr, *p;
0028     struct timespec a, b;
0029     int i = 0;
0030     char *name = NULL;
0031     double s;
0032     uint8_t *map;
0033     size_t map_len;
0034     int pagemap_fd;
0035
0036     ram = sysconf(_SC_PHYS_PAGES);
0037     if (ram > SIZE_MAX / sysconf(_SC_PAGESIZE) / 4)
0038         ram = SIZE_MAX / 4;
0039     else
0040         ram *= sysconf(_SC_PAGESIZE);
0041     len = ram;
0042
0043     while (++i < argc) {
0044         if (!strcmp(argv[i], "-h"))
0045             errx(1, "usage: %s [size in MiB]", argv[0]);
0046         else if (!strcmp(argv[i], "-f"))
0047             name = argv[++i];
0048         else
0049             len = atoll(argv[i]) << 20;
0050     }
0051
0052     if (name) {
0053         backing_fd = open(name, O_RDWR);
0054         if (backing_fd == -1)
0055             errx(2, "open %s", name);
0056         mmap_flags = MAP_SHARED;
0057     }
0058
0059     warnx("allocate %zd transhuge pages, using %zd MiB virtual memory"
0060           " and %zd MiB of ram", len >> HPAGE_SHIFT, len >> 20,
0061           ram >> (20 + HPAGE_SHIFT - PAGE_SHIFT - 1));
0062
0063     pagemap_fd = open("/proc/self/pagemap", O_RDONLY);
0064     if (pagemap_fd < 0)
0065         err(2, "open pagemap");
0066
0067     len -= len % HPAGE_SIZE;
0068     ptr = mmap(NULL, len + HPAGE_SIZE, PROT_RW, mmap_flags, backing_fd, 0);
0069     if (ptr == MAP_FAILED)
0070         err(2, "initial mmap");
0071     ptr += HPAGE_SIZE - (uintptr_t)ptr % HPAGE_SIZE;
0072
0073     if (madvise(ptr, len, MADV_HUGEPAGE))
0074         err(2, "MADV_HUGEPAGE");
0075
0076     map_len = ram >> (HPAGE_SHIFT - 1);
0077     map = malloc(map_len);
0078     if (!map)
0079         errx(2, "map malloc");
0080
0081     while (1) {
0082         int nr_succeed = 0, nr_failed = 0, nr_pages = 0;
0083
0084         memset(map, 0, map_len);
0085
0086         clock_gettime(CLOCK_MONOTONIC, &a);
0087         for (p = ptr; p < ptr + len; p += HPAGE_SIZE) {
0088             int64_t pfn;
0089
0090             pfn = allocate_transhuge(p, pagemap_fd);
0091
0092             if (pfn < 0) {
0093                 nr_failed++;
0094             } else {
0095                 size_t idx = pfn >> (HPAGE_SHIFT - PAGE_SHIFT);
0096
0097                 nr_succeed++;
0098                 if (idx >= map_len) {
0099                     map = realloc(map, idx + 1);
0100                     if (!map)
0101                         errx(2, "map realloc");
0102                     memset(map + map_len, 0, idx + 1 - map_len);
0103                     map_len = idx + 1;
0104                 }
0105                 if (!map[idx])
0106                     nr_pages++;
0107                 map[idx] = 1;
0108             }
0109
0110             /* split transhuge page, keep last page */
0111             if (madvise(p, HPAGE_SIZE - PAGE_SIZE, MADV_DONTNEED))
0112                 err(2, "MADV_DONTNEED");
0113         }
0114         clock_gettime(CLOCK_MONOTONIC, &b);
0115         s = b.tv_sec - a.tv_sec + (b.tv_nsec - a.tv_nsec) / 1000000000.;
0116
0117         warnx("%.3f s/loop, %.3f ms/page, %10.3f MiB/s\t"
0118               "%4d succeed, %4d failed, %4d different pages",
0119               s, s * 1000 / (len >> HPAGE_SHIFT), len / s / (1 << 20),
0120               nr_succeed, nr_failed, nr_pages);
0121     }
0122 }