Add memory operations for file-backed and tmpfs memory. Call existing tests with these new memory operations to test collapse functionality of khugepaged and MADV_COLLAPSE on file-backed and tmpfs memory. Not all tests are reusable; for example, collapse_swapin_single_pte() which checks swap usage. Refactor test arguments. Usage is now: Usage: ./khugepaged <test type> [dir] <test type> : <context>:<mem_type> <context> : [all|khugepaged|madvise] <mem_type> : [all|anon|file] "file,all" mem_type requires [dir] argument "file,all" mem_type requires kernel built with CONFIG_READ_ONLY_THP_FOR_FS=y if [dir] is a (sub)directory of a tmpfs mount, tmpfs must be mounted with huge=madvise option for khugepaged tests to work Refactor calling tests to make it clear what collapse context / memory operations they support, but only invoke tests requested by user. Also log what test is being ran, and with what context / memory, to make test logs more human readable. A new test file is created and deleted for every test to ensure no pages remain in the page cache between tests. Also, disable read_ahead_kb so that pages don't find their way into the page cache without the tests faulting them in. Add file and shmem wrappers to vm_utils check for file and shmem hugepages in smaps. Signed-off-by: Zach O'Keefe <zokeefe@xxxxxxxxxx> --- tools/testing/selftests/vm/khugepaged.c | 401 ++++++++++++++++++++---- tools/testing/selftests/vm/vm_util.c | 10 + tools/testing/selftests/vm/vm_util.h | 2 + 3 files changed, 357 insertions(+), 56 deletions(-) diff --git a/tools/testing/selftests/vm/khugepaged.c b/tools/testing/selftests/vm/khugepaged.c index b4b1709507a5..0ddfffb87411 100644 --- a/tools/testing/selftests/vm/khugepaged.c +++ b/tools/testing/selftests/vm/khugepaged.c @@ -1,6 +1,7 @@ #define _GNU_SOURCE #include <fcntl.h> #include <limits.h> +#include <dirent.h> #include <signal.h> #include <stdio.h> #include <stdlib.h> @@ -10,12 +11,20 @@ #include <sys/mman.h> #include <sys/wait.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/vfs.h> + +#include "linux/magic.h" #include "vm_util.h" #ifndef MADV_PAGEOUT #define MADV_PAGEOUT 21 #endif +#ifndef MADV_POPULATE_READ +#define MADV_POPULATE_READ 22 +#endif #ifndef MADV_COLLAPSE #define MADV_COLLAPSE 25 #endif @@ -26,21 +35,48 @@ static unsigned long page_size; static int hpage_pmd_nr; #define THP_SYSFS "/sys/kernel/mm/transparent_hugepage/" +#define READ_AHEAD_SYSFS "/sys/block/sda/queue/read_ahead_kb" #define PID_SMAPS "/proc/self/smaps" +#define TEST_FILE "collapse_test_file" + +#define MAX_LINE_LENGTH 500 + +enum vma_type { + VMA_ANON, + VMA_FILE, + VMA_SHMEM, +}; struct mem_ops { void *(*setup_area)(int nr_hpages); void (*cleanup_area)(void *p, unsigned long size); void (*fault)(void *p, unsigned long start, unsigned long end); bool (*check_huge)(void *addr, int nr_hpages); + const char *name; }; +static struct mem_ops *file_ops; +static struct mem_ops *anon_ops; + struct collapse_context { void (*collapse)(const char *msg, char *p, int nr_hpages, struct mem_ops *ops, bool expect); bool enforce_pte_scan_limits; + const char *name; +}; + +static struct collapse_context *khugepaged_context; +static struct collapse_context *madvise_context; + +struct file_info { + const char *dir; + char path[MAX_LINE_LENGTH]; + enum vma_type type; + int fd; }; +static struct file_info finfo; + enum thp_enabled { THP_ALWAYS, THP_MADVISE, @@ -106,6 +142,7 @@ struct settings { enum shmem_enabled shmem_enabled; bool use_zero_page; struct khugepaged_settings khugepaged; + unsigned long read_ahead_kb; }; static struct settings saved_settings; @@ -124,6 +161,11 @@ static void fail(const char *msg) exit_status++; } +static void skip(const char *msg) +{ + printf(" \e[33m%s\e[0m\n", msg); +} + static int read_file(const char *path, char *buf, size_t buflen) { int fd; @@ -151,13 +193,19 @@ static int write_file(const char *path, const char *buf, size_t buflen) ssize_t numwritten; fd = open(path, O_WRONLY); - if (fd == -1) + if (fd == -1) { + printf("open(%s)\n", path); + exit(EXIT_FAILURE); return 0; + } numwritten = write(fd, buf, buflen - 1); close(fd); - if (numwritten < 1) + if (numwritten < 1) { + printf("write(%s)\n", buf); + exit(EXIT_FAILURE); return 0; + } return (unsigned int) numwritten; } @@ -224,20 +272,11 @@ static void write_string(const char *name, const char *val) } } -static const unsigned long read_num(const char *name) +static const unsigned long _read_num(const char *path) { - char path[PATH_MAX]; char buf[21]; - int ret; - - ret = snprintf(path, PATH_MAX, THP_SYSFS "%s", name); - if (ret >= PATH_MAX) { - printf("%s: Pathname is too long\n", __func__); - exit(EXIT_FAILURE); - } - ret = read_file(path, buf, sizeof(buf)); - if (ret < 0) { + if (read_file(path, buf, sizeof(buf)) < 0) { perror("read_file(read_num)"); exit(EXIT_FAILURE); } @@ -245,10 +284,9 @@ static const unsigned long read_num(const char *name) return strtoul(buf, NULL, 10); } -static void write_num(const char *name, unsigned long num) +static const unsigned long read_num(const char *name) { char path[PATH_MAX]; - char buf[21]; int ret; ret = snprintf(path, PATH_MAX, THP_SYSFS "%s", name); @@ -256,6 +294,12 @@ static void write_num(const char *name, unsigned long num) printf("%s: Pathname is too long\n", __func__); exit(EXIT_FAILURE); } + return _read_num(path); +} + +static void _write_num(const char *path, unsigned long num) +{ + char buf[21]; sprintf(buf, "%ld", num); if (!write_file(path, buf, strlen(buf) + 1)) { @@ -264,6 +308,19 @@ static void write_num(const char *name, unsigned long num) } } +static void write_num(const char *name, unsigned long num) +{ + char path[PATH_MAX]; + int ret; + + ret = snprintf(path, PATH_MAX, THP_SYSFS "%s", name); + if (ret >= PATH_MAX) { + printf("%s: Pathname is too long\n", __func__); + exit(EXIT_FAILURE); + } + _write_num(path, num); +} + static void write_settings(struct settings *settings) { struct khugepaged_settings *khugepaged = &settings->khugepaged; @@ -283,6 +340,8 @@ static void write_settings(struct settings *settings) write_num("khugepaged/max_ptes_swap", khugepaged->max_ptes_swap); write_num("khugepaged/max_ptes_shared", khugepaged->max_ptes_shared); write_num("khugepaged/pages_to_scan", khugepaged->pages_to_scan); + + _write_num(READ_AHEAD_SYSFS, settings->read_ahead_kb); } #define MAX_SETTINGS_DEPTH 4 @@ -341,6 +400,7 @@ static void save_settings(void) .shmem_enabled = read_string("shmem_enabled", shmem_enabled_strings), .use_zero_page = read_num("use_zero_page"), + .read_ahead_kb = _read_num(READ_AHEAD_SYSFS), }; saved_settings.khugepaged = (struct khugepaged_settings) { .defrag = read_num("khugepaged/defrag"), @@ -361,7 +421,6 @@ static void save_settings(void) signal(SIGQUIT, restore_settings); } -#define MAX_LINE_LENGTH 500 static bool check_swap(void *addr, unsigned long size) { bool swap = false; @@ -489,11 +548,109 @@ static bool anon_check_huge(void *addr, int nr_hpages) return check_huge_anon(addr, nr_hpages, hpage_pmd_size); } -static struct mem_ops anon_ops = { +static void *file_setup_area(int nr_hpages) +{ + struct stat path_stat; + struct statfs fs; + int fd; + void *p; + unsigned long size; + + stat(finfo.dir, &path_stat); + if (!S_ISDIR(path_stat.st_mode)) { + printf("%s: Not a directory (%s)\n", __func__, finfo.dir); + exit(EXIT_FAILURE); + } + if (snprintf(finfo.path, sizeof(finfo.path), "%s/" TEST_FILE, + finfo.dir) >= sizeof(finfo.path)) { + printf("%s: Pathname is too long\n", __func__); + exit(EXIT_FAILURE); + } + if (statfs(finfo.dir, &fs)) { + perror("statfs()"); + exit(EXIT_FAILURE); + } + finfo.type = fs.f_type == TMPFS_MAGIC ? VMA_SHMEM : VMA_FILE; + + unlink(finfo.path); /* Cleanup from previous failed tests */ + printf("Creating %s for collapse%s...", finfo.path, + finfo.type == VMA_SHMEM ? " (tmpfs)" : ""); + fd = open(finfo.path, O_DSYNC | O_CREAT | O_RDWR | O_TRUNC | O_EXCL, + 777); + if (fd < 0) { + perror("open()"); + exit(EXIT_FAILURE); + } + + size = nr_hpages * hpage_pmd_size; + p = alloc_mapping(nr_hpages); + fill_memory(p, 0, size); + write(fd, p, size); + close(fd); + munmap(p, size); + success("OK"); + + printf("Opening %s read only for collapse...", finfo.path); + finfo.fd = open(finfo.path, O_RDONLY, 777); + if (finfo.fd < 0) { + perror("open()"); + exit(EXIT_FAILURE); + } + p = mmap(BASE_ADDR, size, PROT_READ | PROT_EXEC, + MAP_PRIVATE, finfo.fd, 0); + if (p == MAP_FAILED || p != BASE_ADDR) { + perror("mmap()"); + exit(EXIT_FAILURE); + } + + /* Drop page cache */ + write_file("/proc/sys/vm/drop_caches", "3", 2); + success("OK"); + return p; +} + +static void file_cleanup_area(void *p, unsigned long size) +{ + munmap(p, size); + close(finfo.fd); + unlink(finfo.path); +} + +static void file_fault(void *p, unsigned long start, unsigned long end) +{ + if (madvise(((char *)p) + start, end - start, MADV_POPULATE_READ)) { + perror("madvise(MADV_POPULATE_READ"); + exit(EXIT_FAILURE); + } +} + +static bool file_check_huge(void *addr, int nr_hpages) +{ + switch (finfo.type) { + case VMA_FILE: + return check_huge_file(addr, nr_hpages, hpage_pmd_size); + case VMA_SHMEM: + return check_huge_shmem(addr, nr_hpages, hpage_pmd_size); + default: + exit(EXIT_FAILURE); + return false; + } +} + +static struct mem_ops __anon_ops = { .setup_area = &anon_setup_area, .cleanup_area = &anon_cleanup_area, .fault = &anon_fault, .check_huge = &anon_check_huge, + .name = "anon", +}; + +static struct mem_ops __file_ops = { + .setup_area = &file_setup_area, + .cleanup_area = &file_cleanup_area, + .fault = &file_fault, + .check_huge = &file_check_huge, + .name = "file", }; static void __madvise_collapse(const char *msg, char *p, int nr_hpages, @@ -509,6 +666,7 @@ static void __madvise_collapse(const char *msg, char *p, int nr_hpages, * ignores /sys/kernel/mm/transparent_hugepage/enabled */ settings.thp_enabled = THP_NEVER; + settings.shmem_enabled = SHMEM_NEVER; push_settings(&settings); /* Clear VM_NOHUGEPAGE */ @@ -580,12 +738,37 @@ static void khugepaged_collapse(const char *msg, char *p, int nr_hpages, return; } + /* + * For file and shmem memory, khugepaged only retracts pte entries after + * putting the new hugepage in the page cache. The hugepage must be + * subsequently refaulted to install the pmd mapping for the mm. + */ + if (ops != &__anon_ops) + ops->fault(p, 0, nr_hpages * hpage_pmd_size); + if (ops->check_huge(p, expect ? nr_hpages : 0)) success("OK"); else fail("Fail"); } +static struct collapse_context __khugepaged_context = { + .collapse = &khugepaged_collapse, + .enforce_pte_scan_limits = true, + .name = "khugepaged", +}; + +static struct collapse_context __madvise_context = { + .collapse = &madvise_collapse, + .enforce_pte_scan_limits = false, + .name = "madvise", +}; + +static bool is_tmpfs(struct mem_ops *ops) +{ + return ops == &__file_ops && finfo.type == VMA_SHMEM; +} + static void alloc_at_fault(void) { struct settings settings = *current_settings(); @@ -658,6 +841,13 @@ static void collapse_max_ptes_none(struct collapse_context *c, struct mem_ops *o p = ops->setup_area(1); + if (is_tmpfs(ops)) { + /* shmem pages always in the page cache */ + printf("tmpfs..."); + skip("Skip"); + goto skip; + } + ops->fault(p, 0, (hpage_pmd_nr - max_ptes_none - 1) * page_size); c->collapse("Maybe collapse with max_ptes_none exceeded", p, 1, ops, !c->enforce_pte_scan_limits); @@ -670,6 +860,7 @@ static void collapse_max_ptes_none(struct collapse_context *c, struct mem_ops *o validate_memory(p, 0, (hpage_pmd_nr - max_ptes_none) * page_size); } +skip: ops->cleanup_area(p, hpage_pmd_size); pop_settings(); } @@ -753,6 +944,13 @@ static void collapse_single_pte_entry_compound(struct collapse_context *c, struc p = alloc_hpage(ops); + if (is_tmpfs(ops)) { + /* MADV_DONTNEED won't evict tmpfs pages */ + printf("tmpfs..."); + skip("Skip"); + goto skip; + } + madvise(p, hpage_pmd_size, MADV_NOHUGEPAGE); printf("Split huge page leaving single PTE mapping compound page..."); madvise(p + page_size, hpage_pmd_size - page_size, MADV_DONTNEED); @@ -764,6 +962,7 @@ static void collapse_single_pte_entry_compound(struct collapse_context *c, struc c->collapse("Collapse PTE table with single PTE mapping compound page", p, 1, ops, true); validate_memory(p, 0, page_size); +skip: ops->cleanup_area(p, hpage_pmd_size); } @@ -1010,9 +1209,72 @@ static void madvise_collapse_existing_thps(struct collapse_context *c, ops->cleanup_area(p, hpage_pmd_size); } +static void usage(void) +{ + fprintf(stderr, "\nUsage: ./khugepaged <test type> [dir]\n\n"); + fprintf(stderr, "\t<test type>\t: <context>:<mem_type>\n"); + fprintf(stderr, "\t<context>\t: [all|khugepaged|madvise]\n"); + fprintf(stderr, "\t<mem_type>\t: [all|anon|file]\n"); + fprintf(stderr, "\n\t\"file,all\" mem_type requires [dir] argument\n"); + fprintf(stderr, "\n\t\"file,all\" mem_type requires kernel built with\n"); + fprintf(stderr, "\tCONFIG_READ_ONLY_THP_FOR_FS=y\n"); + fprintf(stderr, "\n\tif [dir] is a (sub)directory of a tmpfs mount, tmpfs must be\n"); + fprintf(stderr, "\tmounted with huge=madvise option for khugepaged tests to work\n"); + exit(1); +} + +static void parse_test_type(int argc, const char **argv) +{ + char *buf; + const char *token; + + if (argc == 1) { + /* Backwards compatibility */ + khugepaged_context = &__khugepaged_context; + madvise_context = &__madvise_context; + anon_ops = &__anon_ops; + return; + } + + buf = strdup(argv[1]); + token = strsep(&buf, ":"); + + if (!strcmp(token, "all")) { + khugepaged_context = &__khugepaged_context; + madvise_context = &__madvise_context; + } else if (!strcmp(token, "khugepaged")) { + khugepaged_context = &__khugepaged_context; + } else if (!strcmp(token, "madvise")) { + madvise_context = &__madvise_context; + } else { + usage(); + } + + if (!buf) + usage(); + + if (!strcmp(buf, "all")) { + file_ops = &__file_ops; + anon_ops = &__anon_ops; + } else if (!strcmp(buf, "anon")) { + anon_ops = &__anon_ops; + } else if (!strcmp(buf, "file")) { + file_ops = &__file_ops; + } else { + usage(); + } + + if (!file_ops) + return; + + if (argc != 3) + usage(); + + finfo.dir = argv[2]; +} + int main(int argc, const char **argv) { - struct collapse_context c; struct settings default_settings = { .thp_enabled = THP_MADVISE, .thp_defrag = THP_DEFRAG_ALWAYS, @@ -1023,8 +1285,17 @@ int main(int argc, const char **argv) .alloc_sleep_millisecs = 10, .scan_sleep_millisecs = 10, }, + /* + * When testing file-backed memory, the collapse path + * looks at how many pages are found in the page cache, not + * what pages are mapped. Disable read ahead optimization so + * pages don't find their way into the page cache unless + * we mem_ops->fault() them in. + */ + .read_ahead_kb = 0, }; - const char *tests = argc == 1 ? "all" : argv[1]; + + parse_test_type(argc, argv); setbuf(stdout, NULL); @@ -1042,43 +1313,61 @@ int main(int argc, const char **argv) alloc_at_fault(); - if (!strcmp(tests, "khugepaged") || !strcmp(tests, "all")) { - printf("\n*** Testing context: khugepaged ***\n"); - c.collapse = &khugepaged_collapse; - c.enforce_pte_scan_limits = true; - - collapse_full(&c, &anon_ops); - collapse_empty(&c, &anon_ops); - collapse_single_pte_entry(&c, &anon_ops); - collapse_max_ptes_none(&c, &anon_ops); - collapse_swapin_single_pte(&c, &anon_ops); - collapse_max_ptes_swap(&c, &anon_ops); - collapse_single_pte_entry_compound(&c, &anon_ops); - collapse_full_of_compound(&c, &anon_ops); - collapse_compound_extreme(&c, &anon_ops); - collapse_fork(&c, &anon_ops); - collapse_fork_compound(&c, &anon_ops); - collapse_max_ptes_shared(&c, &anon_ops); - } - if (!strcmp(tests, "madvise") || !strcmp(tests, "all")) { - printf("\n*** Testing context: madvise ***\n"); - c.collapse = &madvise_collapse; - c.enforce_pte_scan_limits = false; - - collapse_full(&c, &anon_ops); - collapse_empty(&c, &anon_ops); - collapse_single_pte_entry(&c, &anon_ops); - collapse_max_ptes_none(&c, &anon_ops); - collapse_swapin_single_pte(&c, &anon_ops); - collapse_max_ptes_swap(&c, &anon_ops); - collapse_single_pte_entry_compound(&c, &anon_ops); - collapse_full_of_compound(&c, &anon_ops); - collapse_compound_extreme(&c, &anon_ops); - collapse_fork(&c, &anon_ops); - collapse_fork_compound(&c, &anon_ops); - collapse_max_ptes_shared(&c, &anon_ops); - madvise_collapse_existing_thps(&c, &anon_ops); - } +#define TEST(t, c, o) do { \ + if (c && o) { \ + printf("\nRun test: " #t " (%s:%s)\n", c->name, o->name); \ + t(c, o); \ + } \ + } while (0) + + TEST(collapse_full, khugepaged_context, anon_ops); + TEST(collapse_full, khugepaged_context, file_ops); + TEST(collapse_full, madvise_context, anon_ops); + TEST(collapse_full, madvise_context, file_ops); + + TEST(collapse_empty, khugepaged_context, anon_ops); + TEST(collapse_empty, madvise_context, anon_ops); + + TEST(collapse_single_pte_entry, khugepaged_context, anon_ops); + TEST(collapse_single_pte_entry, khugepaged_context, file_ops); + TEST(collapse_single_pte_entry, madvise_context, anon_ops); + TEST(collapse_single_pte_entry, madvise_context, file_ops); + + TEST(collapse_max_ptes_none, khugepaged_context, anon_ops); + TEST(collapse_max_ptes_none, khugepaged_context, file_ops); + TEST(collapse_max_ptes_none, madvise_context, anon_ops); + TEST(collapse_max_ptes_none, madvise_context, file_ops); + + TEST(collapse_single_pte_entry_compound, khugepaged_context, anon_ops); + TEST(collapse_single_pte_entry_compound, khugepaged_context, file_ops); + TEST(collapse_single_pte_entry_compound, madvise_context, anon_ops); + TEST(collapse_single_pte_entry_compound, madvise_context, file_ops); + + TEST(collapse_full_of_compound, khugepaged_context, anon_ops); + TEST(collapse_full_of_compound, khugepaged_context, file_ops); + TEST(collapse_full_of_compound, madvise_context, anon_ops); + TEST(collapse_full_of_compound, madvise_context, file_ops); + + TEST(collapse_compound_extreme, khugepaged_context, anon_ops); + TEST(collapse_compound_extreme, madvise_context, anon_ops); + + TEST(collapse_swapin_single_pte, khugepaged_context, anon_ops); + TEST(collapse_swapin_single_pte, madvise_context, anon_ops); + + TEST(collapse_max_ptes_swap, khugepaged_context, anon_ops); + TEST(collapse_max_ptes_swap, madvise_context, anon_ops); + + TEST(collapse_fork, khugepaged_context, anon_ops); + TEST(collapse_fork, madvise_context, anon_ops); + + TEST(collapse_fork_compound, khugepaged_context, anon_ops); + TEST(collapse_fork_compound, madvise_context, anon_ops); + + TEST(collapse_max_ptes_shared, khugepaged_context, anon_ops); + TEST(collapse_max_ptes_shared, madvise_context, anon_ops); + + TEST(madvise_collapse_existing_thps, madvise_context, anon_ops); + TEST(madvise_collapse_existing_thps, madvise_context, file_ops); restore_settings(0); } diff --git a/tools/testing/selftests/vm/vm_util.c b/tools/testing/selftests/vm/vm_util.c index 9dae51b8219f..f11f8adda521 100644 --- a/tools/testing/selftests/vm/vm_util.c +++ b/tools/testing/selftests/vm/vm_util.c @@ -114,3 +114,13 @@ bool check_huge_anon(void *addr, int nr_hpages, uint64_t hpage_size) { return __check_huge(addr, "AnonHugePages: ", nr_hpages, hpage_size); } + +bool check_huge_file(void *addr, int nr_hpages, uint64_t hpage_size) +{ + return __check_huge(addr, "FilePmdMapped:", nr_hpages, hpage_size); +} + +bool check_huge_shmem(void *addr, int nr_hpages, uint64_t hpage_size) +{ + return __check_huge(addr, "ShmemPmdMapped:", nr_hpages, hpage_size); +} diff --git a/tools/testing/selftests/vm/vm_util.h b/tools/testing/selftests/vm/vm_util.h index 8434ea0c95cd..5c35de454e08 100644 --- a/tools/testing/selftests/vm/vm_util.h +++ b/tools/testing/selftests/vm/vm_util.h @@ -8,3 +8,5 @@ void clear_softdirty(void); bool check_for_pattern(FILE *fp, const char *pattern, char *buf, size_t len); uint64_t read_pmd_pagesize(void); bool check_huge_anon(void *addr, int nr_hpages, uint64_t hpage_size); +bool check_huge_file(void *addr, int nr_hpages, uint64_t hpage_size); +bool check_huge_shmem(void *addr, int nr_hpages, uint64_t hpage_size); -- 2.37.2.672.g94769d06f0-goog