![Konstantin Khlebnikov](/assets/img/avatar_default.png)
This tool induces memory fragmentation via sequential allocation of transparent huge pages and splitting off everything except their last sub-pages. It easily generates pressure to the memory compaction code. $ perf stat -e 'compaction:*' -e 'migrate:*' ./transhuge-stress transhuge-stress: allocate 7858 transhuge pages, using 15716 MiB virtual memory and 61 MiB of ram transhuge-stress: 1.653 s/loop, 0.210 ms/page, 9504.828 MiB/s 7858 succeed, 0 failed, 2439 different pages transhuge-stress: 1.537 s/loop, 0.196 ms/page, 10226.227 MiB/s 7858 succeed, 0 failed, 2364 different pages transhuge-stress: 1.658 s/loop, 0.211 ms/page, 9479.215 MiB/s 7858 succeed, 0 failed, 2179 different pages transhuge-stress: 1.617 s/loop, 0.206 ms/page, 9716.992 MiB/s 7858 succeed, 0 failed, 2421 different pages ^C./transhuge-stress: Interrupt Performance counter stats for './transhuge-stress': 1.744.051 compaction:mm_compaction_isolate_migratepages 1.014 compaction:mm_compaction_isolate_freepages 1.744.051 compaction:mm_compaction_migratepages 1.647 compaction:mm_compaction_begin 1.647 compaction:mm_compaction_end 1.744.051 migrate:mm_migrate_pages 0 migrate:mm_numa_migrate_ratelimit 7,964696835 seconds time elapsed Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Rafael Aquini <aquini@redhat.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
145 lines
3.5 KiB
C
145 lines
3.5 KiB
C
/*
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* Stress test for transparent huge pages, memory compaction and migration.
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*
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* Authors: Konstantin Khlebnikov <koct9i@gmail.com>
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*
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* This is free and unencumbered software released into the public domain.
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <stdint.h>
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#include <err.h>
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#include <time.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <string.h>
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#include <sys/mman.h>
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#define PAGE_SHIFT 12
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#define HPAGE_SHIFT 21
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#define PAGE_SIZE (1 << PAGE_SHIFT)
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#define HPAGE_SIZE (1 << HPAGE_SHIFT)
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#define PAGEMAP_PRESENT(ent) (((ent) & (1ull << 63)) != 0)
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#define PAGEMAP_PFN(ent) ((ent) & ((1ull << 55) - 1))
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int pagemap_fd;
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int64_t allocate_transhuge(void *ptr)
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{
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uint64_t ent[2];
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/* drop pmd */
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if (mmap(ptr, HPAGE_SIZE, PROT_READ | PROT_WRITE,
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MAP_FIXED | MAP_ANONYMOUS |
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MAP_NORESERVE | MAP_PRIVATE, -1, 0) != ptr)
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errx(2, "mmap transhuge");
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if (madvise(ptr, HPAGE_SIZE, MADV_HUGEPAGE))
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err(2, "MADV_HUGEPAGE");
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/* allocate transparent huge page */
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*(volatile void **)ptr = ptr;
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if (pread(pagemap_fd, ent, sizeof(ent),
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(uintptr_t)ptr >> (PAGE_SHIFT - 3)) != sizeof(ent))
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err(2, "read pagemap");
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if (PAGEMAP_PRESENT(ent[0]) && PAGEMAP_PRESENT(ent[1]) &&
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PAGEMAP_PFN(ent[0]) + 1 == PAGEMAP_PFN(ent[1]) &&
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!(PAGEMAP_PFN(ent[0]) & ((1 << (HPAGE_SHIFT - PAGE_SHIFT)) - 1)))
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return PAGEMAP_PFN(ent[0]);
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return -1;
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}
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int main(int argc, char **argv)
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{
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size_t ram, len;
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void *ptr, *p;
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struct timespec a, b;
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double s;
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uint8_t *map;
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size_t map_len;
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ram = sysconf(_SC_PHYS_PAGES);
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if (ram > SIZE_MAX / sysconf(_SC_PAGESIZE) / 4)
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ram = SIZE_MAX / 4;
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else
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ram *= sysconf(_SC_PAGESIZE);
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if (argc == 1)
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len = ram;
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else if (!strcmp(argv[1], "-h"))
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errx(1, "usage: %s [size in MiB]", argv[0]);
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else
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len = atoll(argv[1]) << 20;
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warnx("allocate %zd transhuge pages, using %zd MiB virtual memory"
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" and %zd MiB of ram", len >> HPAGE_SHIFT, len >> 20,
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len >> (20 + HPAGE_SHIFT - PAGE_SHIFT - 1));
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pagemap_fd = open("/proc/self/pagemap", O_RDONLY);
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if (pagemap_fd < 0)
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err(2, "open pagemap");
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len -= len % HPAGE_SIZE;
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ptr = mmap(NULL, len + HPAGE_SIZE, PROT_READ | PROT_WRITE,
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MAP_ANONYMOUS | MAP_NORESERVE | MAP_PRIVATE, -1, 0);
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if (ptr == MAP_FAILED)
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err(2, "initial mmap");
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ptr += HPAGE_SIZE - (uintptr_t)ptr % HPAGE_SIZE;
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if (madvise(ptr, len, MADV_HUGEPAGE))
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err(2, "MADV_HUGEPAGE");
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map_len = ram >> (HPAGE_SHIFT - 1);
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map = malloc(map_len);
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if (!map)
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errx(2, "map malloc");
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while (1) {
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int nr_succeed = 0, nr_failed = 0, nr_pages = 0;
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memset(map, 0, map_len);
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clock_gettime(CLOCK_MONOTONIC, &a);
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for (p = ptr; p < ptr + len; p += HPAGE_SIZE) {
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int64_t pfn;
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pfn = allocate_transhuge(p);
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if (pfn < 0) {
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nr_failed++;
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} else {
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size_t idx = pfn >> (HPAGE_SHIFT - PAGE_SHIFT);
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nr_succeed++;
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if (idx >= map_len) {
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map = realloc(map, idx + 1);
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if (!map)
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errx(2, "map realloc");
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memset(map + map_len, 0, idx + 1 - map_len);
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map_len = idx + 1;
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}
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if (!map[idx])
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nr_pages++;
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map[idx] = 1;
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}
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/* split transhuge page, keep last page */
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if (madvise(p, HPAGE_SIZE - PAGE_SIZE, MADV_DONTNEED))
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err(2, "MADV_DONTNEED");
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}
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clock_gettime(CLOCK_MONOTONIC, &b);
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s = b.tv_sec - a.tv_sec + (b.tv_nsec - a.tv_nsec) / 1000000000.;
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warnx("%.3f s/loop, %.3f ms/page, %10.3f MiB/s\t"
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"%4d succeed, %4d failed, %4d different pages",
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s, s * 1000 / (len >> HPAGE_SHIFT), len / s / (1 << 20),
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nr_succeed, nr_failed, nr_pages);
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}
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}
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