From: Pedro Demarchi Gomes <pedrodemargomes@xxxxxxxxx> Subject: selftests: vm: add KSM huge pages merging time test Add test case of KSM merging time using mostly huge pages Link: https://lkml.kernel.org/r/20211013044045.360251-1-pedrodemargomes@xxxxxxxxx Signed-off-by: Pedro Demarchi Gomes <pedrodemargomes@xxxxxxxxx> Cc: Zhansaya Bagdauletkyzy <zhansayabagdaulet@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/vm/ksm_tests.c | 125 ++++++++++++++++++++++- 1 file changed, 124 insertions(+), 1 deletion(-) --- a/tools/testing/selftests/vm/ksm_tests.c~selftests-vm-add-ksm-huge-pages-merging-time-test +++ a/tools/testing/selftests/vm/ksm_tests.c @@ -5,6 +5,10 @@ #include <time.h> #include <string.h> #include <numa.h> +#include <unistd.h> +#include <fcntl.h> +#include <stdint.h> +#include <err.h> #include "../kselftest.h" #include "../../../../include/vdso/time64.h" @@ -18,6 +22,15 @@ #define KSM_MERGE_ACROSS_NODES_DEFAULT true #define MB (1ul << 20) +#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)) + struct ksm_sysfs { unsigned long max_page_sharing; unsigned long merge_across_nodes; @@ -34,6 +47,7 @@ enum ksm_test_name { CHECK_KSM_ZERO_PAGE_MERGE, CHECK_KSM_NUMA_MERGE, KSM_MERGE_TIME, + KSM_MERGE_TIME_HUGE_PAGES, KSM_COW_TIME }; @@ -100,6 +114,9 @@ static void print_help(void) " -P evaluate merging time and speed.\n" " For this test, the size of duplicated memory area (in MiB)\n" " must be provided using -s option\n" + " -H evaluate merging time and speed of area allocated mostly with huge pages\n" + " For this test, the size of duplicated memory area (in MiB)\n" + " must be provided using -s option\n" " -C evaluate the time required to break COW of merged pages.\n\n"); printf(" -a: specify the access protections of pages.\n" @@ -439,6 +456,101 @@ err_out: return KSFT_FAIL; } +int64_t allocate_transhuge(void *ptr, int pagemap_fd) +{ + 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; +} + +static int ksm_merge_hugepages_time(int mapping, int prot, int timeout, size_t map_size) +{ + void *map_ptr, *map_ptr_orig; + struct timespec start_time, end_time; + unsigned long scan_time_ns; + int pagemap_fd, n_normal_pages, n_huge_pages; + + map_size *= MB; + size_t len = map_size; + + len -= len % HPAGE_SIZE; + map_ptr_orig = mmap(NULL, len + HPAGE_SIZE, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_NORESERVE | MAP_PRIVATE, -1, 0); + map_ptr = map_ptr_orig + HPAGE_SIZE - (uintptr_t)map_ptr_orig % HPAGE_SIZE; + + if (map_ptr_orig == MAP_FAILED) + err(2, "initial mmap"); + + if (madvise(map_ptr, len + HPAGE_SIZE, MADV_HUGEPAGE)) + err(2, "MADV_HUGEPAGE"); + + pagemap_fd = open("/proc/self/pagemap", O_RDONLY); + if (pagemap_fd < 0) + err(2, "open pagemap"); + + n_normal_pages = 0; + n_huge_pages = 0; + for (void *p = map_ptr; p < map_ptr + len; p += HPAGE_SIZE) { + if (allocate_transhuge(p, pagemap_fd) < 0) + n_normal_pages++; + else + n_huge_pages++; + } + printf("Number of normal pages: %d\n", n_normal_pages); + printf("Number of huge pages: %d\n", n_huge_pages); + + memset(map_ptr, '*', len); + + if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) { + perror("clock_gettime"); + goto err_out; + } + if (ksm_merge_pages(map_ptr, map_size, start_time, timeout)) + goto err_out; + if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) { + perror("clock_gettime"); + goto err_out; + } + + scan_time_ns = (end_time.tv_sec - start_time.tv_sec) * NSEC_PER_SEC + + (end_time.tv_nsec - start_time.tv_nsec); + + printf("Total size: %lu MiB\n", map_size / MB); + printf("Total time: %ld.%09ld s\n", scan_time_ns / NSEC_PER_SEC, + scan_time_ns % NSEC_PER_SEC); + printf("Average speed: %.3f MiB/s\n", (map_size / MB) / + ((double)scan_time_ns / NSEC_PER_SEC)); + + munmap(map_ptr_orig, len + HPAGE_SIZE); + return KSFT_PASS; + +err_out: + printf("Not OK\n"); + munmap(map_ptr_orig, len + HPAGE_SIZE); + return KSFT_FAIL; +} + static int ksm_merge_time(int mapping, int prot, int timeout, size_t map_size) { void *map_ptr; @@ -564,7 +676,7 @@ int main(int argc, char *argv[]) bool merge_across_nodes = KSM_MERGE_ACROSS_NODES_DEFAULT; long size_MB = 0; - while ((opt = getopt(argc, argv, "ha:p:l:z:m:s:MUZNPC")) != -1) { + while ((opt = getopt(argc, argv, "ha:p:l:z:m:s:MUZNPCH")) != -1) { switch (opt) { case 'a': prot = str_to_prot(optarg); @@ -618,6 +730,9 @@ int main(int argc, char *argv[]) case 'P': test_name = KSM_MERGE_TIME; break; + case 'H': + test_name = KSM_MERGE_TIME_HUGE_PAGES; + break; case 'C': test_name = KSM_COW_TIME; break; @@ -670,6 +785,14 @@ int main(int argc, char *argv[]) ret = ksm_merge_time(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec, size_MB); break; + case KSM_MERGE_TIME_HUGE_PAGES: + if (size_MB == 0) { + printf("Option '-s' is required.\n"); + return KSFT_FAIL; + } + ret = ksm_merge_hugepages_time(MAP_PRIVATE | MAP_ANONYMOUS, prot, + ksm_scan_limit_sec, size_MB); + break; case KSM_COW_TIME: ret = ksm_cow_time(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec, page_size); _
