From 0085d61fe05ec5a3739afb8ffb8a88130402633e Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Thu, 9 Oct 2014 15:29:34 -0700 Subject: [PATCH] selftests/vm/transhuge-stress: stress test for memory compaction 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 Cc: Rafael Aquini Cc: Andrey Ryabinin Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- tools/testing/selftests/vm/Makefile | 1 + tools/testing/selftests/vm/transhuge-stress.c | 144 ++++++++++++++++++ 2 files changed, 145 insertions(+) create mode 100644 tools/testing/selftests/vm/transhuge-stress.c diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile index 3f94e1afd6cf..4c4b1f631ecf 100644 --- a/tools/testing/selftests/vm/Makefile +++ b/tools/testing/selftests/vm/Makefile @@ -3,6 +3,7 @@ CC = $(CROSS_COMPILE)gcc CFLAGS = -Wall BINARIES = hugepage-mmap hugepage-shm map_hugetlb thuge-gen hugetlbfstest +BINARIES += transhuge-stress all: $(BINARIES) %: %.c diff --git a/tools/testing/selftests/vm/transhuge-stress.c b/tools/testing/selftests/vm/transhuge-stress.c new file mode 100644 index 000000000000..fd7f1b4a96f9 --- /dev/null +++ b/tools/testing/selftests/vm/transhuge-stress.c @@ -0,0 +1,144 @@ +/* + * Stress test for transparent huge pages, memory compaction and migration. + * + * Authors: Konstantin Khlebnikov + * + * This is free and unencumbered software released into the public domain. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define PAGE_SHIFT 12 +#define HPAGE_SHIFT 21 + +#define PAGE_SIZE (1 << PAGE_SHIFT) +#define HPAGE_SIZE (1 << HPAGE_SHIFT) + +#define PAGEMAP_PRESENT(ent) (((ent) & (1ull << 63)) != 0) +#define PAGEMAP_PFN(ent) ((ent) & ((1ull << 55) - 1)) + +int pagemap_fd; + +int64_t allocate_transhuge(void *ptr) +{ + uint64_t ent[2]; + + /* drop pmd */ + if (mmap(ptr, HPAGE_SIZE, PROT_READ | PROT_WRITE, + MAP_FIXED | MAP_ANONYMOUS | + MAP_NORESERVE | MAP_PRIVATE, -1, 0) != ptr) + errx(2, "mmap transhuge"); + + if (madvise(ptr, HPAGE_SIZE, MADV_HUGEPAGE)) + err(2, "MADV_HUGEPAGE"); + + /* allocate transparent huge page */ + *(volatile void **)ptr = ptr; + + if (pread(pagemap_fd, ent, sizeof(ent), + (uintptr_t)ptr >> (PAGE_SHIFT - 3)) != sizeof(ent)) + err(2, "read pagemap"); + + if (PAGEMAP_PRESENT(ent[0]) && PAGEMAP_PRESENT(ent[1]) && + PAGEMAP_PFN(ent[0]) + 1 == PAGEMAP_PFN(ent[1]) && + !(PAGEMAP_PFN(ent[0]) & ((1 << (HPAGE_SHIFT - PAGE_SHIFT)) - 1))) + return PAGEMAP_PFN(ent[0]); + + return -1; +} + +int main(int argc, char **argv) +{ + size_t ram, len; + void *ptr, *p; + struct timespec a, b; + double s; + uint8_t *map; + size_t map_len; + + ram = sysconf(_SC_PHYS_PAGES); + if (ram > SIZE_MAX / sysconf(_SC_PAGESIZE) / 4) + ram = SIZE_MAX / 4; + else + ram *= sysconf(_SC_PAGESIZE); + + if (argc == 1) + len = ram; + else if (!strcmp(argv[1], "-h")) + errx(1, "usage: %s [size in MiB]", argv[0]); + else + len = atoll(argv[1]) << 20; + + warnx("allocate %zd transhuge pages, using %zd MiB virtual memory" + " and %zd MiB of ram", len >> HPAGE_SHIFT, len >> 20, + len >> (20 + HPAGE_SHIFT - PAGE_SHIFT - 1)); + + pagemap_fd = open("/proc/self/pagemap", O_RDONLY); + if (pagemap_fd < 0) + err(2, "open pagemap"); + + len -= len % HPAGE_SIZE; + ptr = mmap(NULL, len + HPAGE_SIZE, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_NORESERVE | MAP_PRIVATE, -1, 0); + if (ptr == MAP_FAILED) + err(2, "initial mmap"); + ptr += HPAGE_SIZE - (uintptr_t)ptr % HPAGE_SIZE; + + if (madvise(ptr, len, MADV_HUGEPAGE)) + err(2, "MADV_HUGEPAGE"); + + map_len = ram >> (HPAGE_SHIFT - 1); + map = malloc(map_len); + if (!map) + errx(2, "map malloc"); + + while (1) { + int nr_succeed = 0, nr_failed = 0, nr_pages = 0; + + memset(map, 0, map_len); + + clock_gettime(CLOCK_MONOTONIC, &a); + for (p = ptr; p < ptr + len; p += HPAGE_SIZE) { + int64_t pfn; + + pfn = allocate_transhuge(p); + + if (pfn < 0) { + nr_failed++; + } else { + size_t idx = pfn >> (HPAGE_SHIFT - PAGE_SHIFT); + + nr_succeed++; + if (idx >= map_len) { + map = realloc(map, idx + 1); + if (!map) + errx(2, "map realloc"); + memset(map + map_len, 0, idx + 1 - map_len); + map_len = idx + 1; + } + if (!map[idx]) + nr_pages++; + map[idx] = 1; + } + + /* split transhuge page, keep last page */ + if (madvise(p, HPAGE_SIZE - PAGE_SIZE, MADV_DONTNEED)) + err(2, "MADV_DONTNEED"); + } + clock_gettime(CLOCK_MONOTONIC, &b); + s = b.tv_sec - a.tv_sec + (b.tv_nsec - a.tv_nsec) / 1000000000.; + + warnx("%.3f s/loop, %.3f ms/page, %10.3f MiB/s\t" + "%4d succeed, %4d failed, %4d different pages", + s, s * 1000 / (len >> HPAGE_SHIFT), len / s / (1 << 20), + nr_succeed, nr_failed, nr_pages); + } +} -- 2.20.1