From d830020656c5b68ced962ed3cb51a90e0a89d4c4 Mon Sep 17 00:00:00 2001 From: Gaurav Singh Date: Thu, 6 Aug 2020 23:17:25 -0700 Subject: tools/testing/selftests/cgroup/cgroup_util.c: cg_read_strcmp: fix null pointer dereference Haven't reproduced this issue. This PR is does a minor code cleanup. Signed-off-by: Gaurav Singh Signed-off-by: Andrew Morton Reviewed-by: Andrew Morton Cc: Shuah Khan Cc: Tejun Heo Cc: Michal Koutn Cc: Roman Gushchin Cc: Christian Brauner Cc: Chris Down Link: http://lkml.kernel.org/r/20200726013808.22242-1-gaurav1086@gmail.com Signed-off-by: Linus Torvalds --- tools/testing/selftests/cgroup/cgroup_util.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools/testing/selftests') diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c index 8a637ca7d73a..05853b0b8831 100644 --- a/tools/testing/selftests/cgroup/cgroup_util.c +++ b/tools/testing/selftests/cgroup/cgroup_util.c @@ -106,7 +106,7 @@ int cg_read_strcmp(const char *cgroup, const char *control, /* Handle the case of comparing against empty string */ if (!expected) - size = 32; + return -1; else size = strlen(expected) + 1; -- cgit v1.2.3 From 933dc80ec262ed8b1cc2ab463d989e1f59ee05c4 Mon Sep 17 00:00:00 2001 From: Roman Gushchin Date: Thu, 6 Aug 2020 23:21:30 -0700 Subject: kselftests: cgroup: add kernel memory accounting tests Add some tests to cover the kernel memory accounting functionality. These are covering some issues (and changes) we had recently. 1) A test which allocates a lot of negative dentries, checks memcg slab statistics, creates memory pressure by setting memory.max to some low value and checks that some number of slabs was reclaimed. 2) A test which covers side effects of memcg destruction: it creates and destroys a large number of sub-cgroups, each containing a multi-threaded workload which allocates and releases some kernel memory. Then it checks that the charge ans memory.stats do add up on the parent level. 3) A test which reads /proc/kpagecgroup and implicitly checks that it doesn't crash the system. 4) A test which spawns a large number of threads and checks that the kernel stacks accounting works as expected. 5) A test which checks that living charged slab objects are not preventing the memory cgroup from being released after being deleted by a user. Signed-off-by: Roman Gushchin Signed-off-by: Andrew Morton Cc: Christoph Lameter Cc: Johannes Weiner Cc: Michal Hocko Cc: Shakeel Butt Cc: Tejun Heo Cc: Vlastimil Babka Link: http://lkml.kernel.org/r/20200623174037.3951353-19-guro@fb.com Signed-off-by: Linus Torvalds --- tools/testing/selftests/cgroup/.gitignore | 1 + tools/testing/selftests/cgroup/Makefile | 2 + tools/testing/selftests/cgroup/test_kmem.c | 382 +++++++++++++++++++++++++++++ 3 files changed, 385 insertions(+) create mode 100644 tools/testing/selftests/cgroup/test_kmem.c (limited to 'tools/testing/selftests') diff --git a/tools/testing/selftests/cgroup/.gitignore b/tools/testing/selftests/cgroup/.gitignore index aa6de65b0838..84cfcabea838 100644 --- a/tools/testing/selftests/cgroup/.gitignore +++ b/tools/testing/selftests/cgroup/.gitignore @@ -2,3 +2,4 @@ test_memcontrol test_core test_freezer +test_kmem \ No newline at end of file diff --git a/tools/testing/selftests/cgroup/Makefile b/tools/testing/selftests/cgroup/Makefile index 967f268fde74..f027d933595b 100644 --- a/tools/testing/selftests/cgroup/Makefile +++ b/tools/testing/selftests/cgroup/Makefile @@ -6,11 +6,13 @@ all: TEST_FILES := with_stress.sh TEST_PROGS := test_stress.sh TEST_GEN_PROGS = test_memcontrol +TEST_GEN_PROGS += test_kmem TEST_GEN_PROGS += test_core TEST_GEN_PROGS += test_freezer include ../lib.mk $(OUTPUT)/test_memcontrol: cgroup_util.c ../clone3/clone3_selftests.h +$(OUTPUT)/test_kmem: cgroup_util.c ../clone3/clone3_selftests.h $(OUTPUT)/test_core: cgroup_util.c ../clone3/clone3_selftests.h $(OUTPUT)/test_freezer: cgroup_util.c ../clone3/clone3_selftests.h diff --git a/tools/testing/selftests/cgroup/test_kmem.c b/tools/testing/selftests/cgroup/test_kmem.c new file mode 100644 index 000000000000..5224dae216e5 --- /dev/null +++ b/tools/testing/selftests/cgroup/test_kmem.c @@ -0,0 +1,382 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "../kselftest.h" +#include "cgroup_util.h" + + +static int alloc_dcache(const char *cgroup, void *arg) +{ + unsigned long i; + struct stat st; + char buf[128]; + + for (i = 0; i < (unsigned long)arg; i++) { + snprintf(buf, sizeof(buf), + "/something-non-existent-with-a-long-name-%64lu-%d", + i, getpid()); + stat(buf, &st); + } + + return 0; +} + +/* + * This test allocates 100000 of negative dentries with long names. + * Then it checks that "slab" in memory.stat is larger than 1M. + * Then it sets memory.high to 1M and checks that at least 1/2 + * of slab memory has been reclaimed. + */ +static int test_kmem_basic(const char *root) +{ + int ret = KSFT_FAIL; + char *cg = NULL; + long slab0, slab1, current; + + cg = cg_name(root, "kmem_basic_test"); + if (!cg) + goto cleanup; + + if (cg_create(cg)) + goto cleanup; + + if (cg_run(cg, alloc_dcache, (void *)100000)) + goto cleanup; + + slab0 = cg_read_key_long(cg, "memory.stat", "slab "); + if (slab0 < (1 << 20)) + goto cleanup; + + cg_write(cg, "memory.high", "1M"); + slab1 = cg_read_key_long(cg, "memory.stat", "slab "); + if (slab1 <= 0) + goto cleanup; + + current = cg_read_long(cg, "memory.current"); + if (current <= 0) + goto cleanup; + + if (slab1 < slab0 / 2 && current < slab0 / 2) + ret = KSFT_PASS; +cleanup: + cg_destroy(cg); + free(cg); + + return ret; +} + +static void *alloc_kmem_fn(void *arg) +{ + alloc_dcache(NULL, (void *)100); + return NULL; +} + +static int alloc_kmem_smp(const char *cgroup, void *arg) +{ + int nr_threads = 2 * get_nprocs(); + pthread_t *tinfo; + unsigned long i; + int ret = -1; + + tinfo = calloc(nr_threads, sizeof(pthread_t)); + if (tinfo == NULL) + return -1; + + for (i = 0; i < nr_threads; i++) { + if (pthread_create(&tinfo[i], NULL, &alloc_kmem_fn, + (void *)i)) { + free(tinfo); + return -1; + } + } + + for (i = 0; i < nr_threads; i++) { + ret = pthread_join(tinfo[i], NULL); + if (ret) + break; + } + + free(tinfo); + return ret; +} + +static int cg_run_in_subcgroups(const char *parent, + int (*fn)(const char *cgroup, void *arg), + void *arg, int times) +{ + char *child; + int i; + + for (i = 0; i < times; i++) { + child = cg_name_indexed(parent, "child", i); + if (!child) + return -1; + + if (cg_create(child)) { + cg_destroy(child); + free(child); + return -1; + } + + if (cg_run(child, fn, NULL)) { + cg_destroy(child); + free(child); + return -1; + } + + cg_destroy(child); + free(child); + } + + return 0; +} + +/* + * The test creates and destroys a large number of cgroups. In each cgroup it + * allocates some slab memory (mostly negative dentries) using 2 * NR_CPUS + * threads. Then it checks the sanity of numbers on the parent level: + * the total size of the cgroups should be roughly equal to + * anon + file + slab + kernel_stack. + */ +static int test_kmem_memcg_deletion(const char *root) +{ + long current, slab, anon, file, kernel_stack, sum; + int ret = KSFT_FAIL; + char *parent; + + parent = cg_name(root, "kmem_memcg_deletion_test"); + if (!parent) + goto cleanup; + + if (cg_create(parent)) + goto cleanup; + + if (cg_write(parent, "cgroup.subtree_control", "+memory")) + goto cleanup; + + if (cg_run_in_subcgroups(parent, alloc_kmem_smp, NULL, 100)) + goto cleanup; + + current = cg_read_long(parent, "memory.current"); + slab = cg_read_key_long(parent, "memory.stat", "slab "); + anon = cg_read_key_long(parent, "memory.stat", "anon "); + file = cg_read_key_long(parent, "memory.stat", "file "); + kernel_stack = cg_read_key_long(parent, "memory.stat", "kernel_stack "); + if (current < 0 || slab < 0 || anon < 0 || file < 0 || + kernel_stack < 0) + goto cleanup; + + sum = slab + anon + file + kernel_stack; + if (abs(sum - current) < 4096 * 32 * 2 * get_nprocs()) { + ret = KSFT_PASS; + } else { + printf("memory.current = %ld\n", current); + printf("slab + anon + file + kernel_stack = %ld\n", sum); + printf("slab = %ld\n", slab); + printf("anon = %ld\n", anon); + printf("file = %ld\n", file); + printf("kernel_stack = %ld\n", kernel_stack); + } + +cleanup: + cg_destroy(parent); + free(parent); + + return ret; +} + +/* + * The test reads the entire /proc/kpagecgroup. If the operation went + * successfully (and the kernel didn't panic), the test is treated as passed. + */ +static int test_kmem_proc_kpagecgroup(const char *root) +{ + unsigned long buf[128]; + int ret = KSFT_FAIL; + ssize_t len; + int fd; + + fd = open("/proc/kpagecgroup", O_RDONLY); + if (fd < 0) + return ret; + + do { + len = read(fd, buf, sizeof(buf)); + } while (len > 0); + + if (len == 0) + ret = KSFT_PASS; + + close(fd); + return ret; +} + +static void *pthread_wait_fn(void *arg) +{ + sleep(100); + return NULL; +} + +static int spawn_1000_threads(const char *cgroup, void *arg) +{ + int nr_threads = 1000; + pthread_t *tinfo; + unsigned long i; + long stack; + int ret = -1; + + tinfo = calloc(nr_threads, sizeof(pthread_t)); + if (tinfo == NULL) + return -1; + + for (i = 0; i < nr_threads; i++) { + if (pthread_create(&tinfo[i], NULL, &pthread_wait_fn, + (void *)i)) { + free(tinfo); + return(-1); + } + } + + stack = cg_read_key_long(cgroup, "memory.stat", "kernel_stack "); + if (stack >= 4096 * 1000) + ret = 0; + + free(tinfo); + return ret; +} + +/* + * The test spawns a process, which spawns 1000 threads. Then it checks + * that memory.stat's kernel_stack is at least 1000 pages large. + */ +static int test_kmem_kernel_stacks(const char *root) +{ + int ret = KSFT_FAIL; + char *cg = NULL; + + cg = cg_name(root, "kmem_kernel_stacks_test"); + if (!cg) + goto cleanup; + + if (cg_create(cg)) + goto cleanup; + + if (cg_run(cg, spawn_1000_threads, NULL)) + goto cleanup; + + ret = KSFT_PASS; +cleanup: + cg_destroy(cg); + free(cg); + + return ret; +} + +/* + * This test sequentionally creates 30 child cgroups, allocates some + * kernel memory in each of them, and deletes them. Then it checks + * that the number of dying cgroups on the parent level is 0. + */ +static int test_kmem_dead_cgroups(const char *root) +{ + int ret = KSFT_FAIL; + char *parent; + long dead; + int i; + + parent = cg_name(root, "kmem_dead_cgroups_test"); + if (!parent) + goto cleanup; + + if (cg_create(parent)) + goto cleanup; + + if (cg_write(parent, "cgroup.subtree_control", "+memory")) + goto cleanup; + + if (cg_run_in_subcgroups(parent, alloc_dcache, (void *)100, 30)) + goto cleanup; + + for (i = 0; i < 5; i++) { + dead = cg_read_key_long(parent, "cgroup.stat", + "nr_dying_descendants "); + if (dead == 0) { + ret = KSFT_PASS; + break; + } + /* + * Reclaiming cgroups might take some time, + * let's wait a bit and repeat. + */ + sleep(1); + } + +cleanup: + cg_destroy(parent); + free(parent); + + return ret; +} + +#define T(x) { x, #x } +struct kmem_test { + int (*fn)(const char *root); + const char *name; +} tests[] = { + T(test_kmem_basic), + T(test_kmem_memcg_deletion), + T(test_kmem_proc_kpagecgroup), + T(test_kmem_kernel_stacks), + T(test_kmem_dead_cgroups), +}; +#undef T + +int main(int argc, char **argv) +{ + char root[PATH_MAX]; + int i, ret = EXIT_SUCCESS; + + if (cg_find_unified_root(root, sizeof(root))) + ksft_exit_skip("cgroup v2 isn't mounted\n"); + + /* + * Check that memory controller is available: + * memory is listed in cgroup.controllers + */ + if (cg_read_strstr(root, "cgroup.controllers", "memory")) + ksft_exit_skip("memory controller isn't available\n"); + + if (cg_read_strstr(root, "cgroup.subtree_control", "memory")) + if (cg_write(root, "cgroup.subtree_control", "+memory")) + ksft_exit_skip("Failed to set memory controller\n"); + + for (i = 0; i < ARRAY_SIZE(tests); i++) { + switch (tests[i].fn(root)) { + case KSFT_PASS: + ksft_test_result_pass("%s\n", tests[i].name); + break; + case KSFT_SKIP: + ksft_test_result_skip("%s\n", tests[i].name); + break; + default: + ret = EXIT_FAILURE; + ksft_test_result_fail("%s\n", tests[i].name); + break; + } + } + + return ret; +} -- cgit v1.2.3 From 7a309195d11cde854eb75559fbd6b48f9e518f25 Mon Sep 17 00:00:00 2001 From: Ricardo Cañuelo Date: Thu, 6 Aug 2020 23:23:51 -0700 Subject: selftests: add mincore() tests MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add a test suite for the mincore() syscall. It tests most of its use cases as well as its interface. Tests implemented: - basic interface test - behavior on anonymous mappings - behavior on anonymous mappings with huge tlb pages - file-backed mapping with a regular file - file-backed mapping with a tmpfs file Signed-off-by: Ricardo Cañuelo Signed-off-by: Andrew Morton Link: http://lkml.kernel.org/r/20200728100450.4065-1-ricardo.canuelo@collabora.com Signed-off-by: Linus Torvalds --- tools/testing/selftests/Makefile | 1 + tools/testing/selftests/mincore/.gitignore | 2 + tools/testing/selftests/mincore/Makefile | 6 + tools/testing/selftests/mincore/mincore_selftest.c | 361 +++++++++++++++++++++ 4 files changed, 370 insertions(+) create mode 100644 tools/testing/selftests/mincore/.gitignore create mode 100644 tools/testing/selftests/mincore/Makefile create mode 100644 tools/testing/selftests/mincore/mincore_selftest.c (limited to 'tools/testing/selftests') diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index e03bc15ce731..9018f45d631d 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -32,6 +32,7 @@ TARGETS += lkdtm TARGETS += membarrier TARGETS += memfd TARGETS += memory-hotplug +TARGETS += mincore TARGETS += mount TARGETS += mqueue TARGETS += net diff --git a/tools/testing/selftests/mincore/.gitignore b/tools/testing/selftests/mincore/.gitignore new file mode 100644 index 000000000000..15c4dfc2df00 --- /dev/null +++ b/tools/testing/selftests/mincore/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0+ +mincore_selftest diff --git a/tools/testing/selftests/mincore/Makefile b/tools/testing/selftests/mincore/Makefile new file mode 100644 index 000000000000..38c7db1e8926 --- /dev/null +++ b/tools/testing/selftests/mincore/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0+ + +CFLAGS += -Wall + +TEST_GEN_PROGS := mincore_selftest +include ../lib.mk diff --git a/tools/testing/selftests/mincore/mincore_selftest.c b/tools/testing/selftests/mincore/mincore_selftest.c new file mode 100644 index 000000000000..5a1e85ff5d32 --- /dev/null +++ b/tools/testing/selftests/mincore/mincore_selftest.c @@ -0,0 +1,361 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * kselftest suite for mincore(). + * + * Copyright (C) 2020 Collabora, Ltd. + */ + +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "../kselftest.h" +#include "../kselftest_harness.h" + +/* Default test file size: 4MB */ +#define MB (1UL << 20) +#define FILE_SIZE (4 * MB) + + +/* + * Tests the user interface. This test triggers most of the documented + * error conditions in mincore(). + */ +TEST(basic_interface) +{ + int retval; + int page_size; + unsigned char vec[1]; + char *addr; + + page_size = sysconf(_SC_PAGESIZE); + + /* Query a 0 byte sized range */ + retval = mincore(0, 0, vec); + EXPECT_EQ(0, retval); + + /* Addresses in the specified range are invalid or unmapped */ + errno = 0; + retval = mincore(NULL, page_size, vec); + EXPECT_EQ(-1, retval); + EXPECT_EQ(ENOMEM, errno); + + errno = 0; + addr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_ANONYMOUS, -1, 0); + ASSERT_NE(MAP_FAILED, addr) { + TH_LOG("mmap error: %s", strerror(errno)); + } + + /* argument is not page-aligned */ + errno = 0; + retval = mincore(addr + 1, page_size, vec); + EXPECT_EQ(-1, retval); + EXPECT_EQ(EINVAL, errno); + + /* argument is too large */ + errno = 0; + retval = mincore(addr, -1, vec); + EXPECT_EQ(-1, retval); + EXPECT_EQ(ENOMEM, errno); + + /* argument points to an illegal address */ + errno = 0; + retval = mincore(addr, page_size, NULL); + EXPECT_EQ(-1, retval); + EXPECT_EQ(EFAULT, errno); + munmap(addr, page_size); +} + + +/* + * Test mincore() behavior on a private anonymous page mapping. + * Check that the page is not loaded into memory right after the mapping + * but after accessing it (on-demand allocation). + * Then free the page and check that it's not memory-resident. + */ +TEST(check_anonymous_locked_pages) +{ + unsigned char vec[1]; + char *addr; + int retval; + int page_size; + + page_size = sysconf(_SC_PAGESIZE); + + /* Map one page and check it's not memory-resident */ + errno = 0; + addr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + ASSERT_NE(MAP_FAILED, addr) { + TH_LOG("mmap error: %s", strerror(errno)); + } + retval = mincore(addr, page_size, vec); + ASSERT_EQ(0, retval); + ASSERT_EQ(0, vec[0]) { + TH_LOG("Page found in memory before use"); + } + + /* Touch the page and check again. It should now be in memory */ + addr[0] = 1; + mlock(addr, page_size); + retval = mincore(addr, page_size, vec); + ASSERT_EQ(0, retval); + ASSERT_EQ(1, vec[0]) { + TH_LOG("Page not found in memory after use"); + } + + /* + * It shouldn't be memory-resident after unlocking it and + * marking it as unneeded. + */ + munlock(addr, page_size); + madvise(addr, page_size, MADV_DONTNEED); + retval = mincore(addr, page_size, vec); + ASSERT_EQ(0, retval); + ASSERT_EQ(0, vec[0]) { + TH_LOG("Page in memory after being zapped"); + } + munmap(addr, page_size); +} + + +/* + * Check mincore() behavior on huge pages. + * This test will be skipped if the mapping fails (ie. if there are no + * huge pages available). + * + * Make sure the system has at least one free huge page, check + * "HugePages_Free" in /proc/meminfo. + * Increment /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages if + * needed. + */ +TEST(check_huge_pages) +{ + unsigned char vec[1]; + char *addr; + int retval; + int page_size; + + page_size = sysconf(_SC_PAGESIZE); + + errno = 0; + addr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, + -1, 0); + if (addr == MAP_FAILED) { + if (errno == ENOMEM) + SKIP(return, "No huge pages available."); + else + TH_LOG("mmap error: %s", strerror(errno)); + } + retval = mincore(addr, page_size, vec); + ASSERT_EQ(0, retval); + ASSERT_EQ(0, vec[0]) { + TH_LOG("Page found in memory before use"); + } + + addr[0] = 1; + mlock(addr, page_size); + retval = mincore(addr, page_size, vec); + ASSERT_EQ(0, retval); + ASSERT_EQ(1, vec[0]) { + TH_LOG("Page not found in memory after use"); + } + + munlock(addr, page_size); + munmap(addr, page_size); +} + + +/* + * Test mincore() behavior on a file-backed page. + * No pages should be loaded into memory right after the mapping. Then, + * accessing any address in the mapping range should load the page + * containing the address and a number of subsequent pages (readahead). + * + * The actual readahead settings depend on the test environment, so we + * can't make a lot of assumptions about that. This test covers the most + * general cases. + */ +TEST(check_file_mmap) +{ + unsigned char *vec; + int vec_size; + char *addr; + int retval; + int page_size; + int fd; + int i; + int ra_pages = 0; + + page_size = sysconf(_SC_PAGESIZE); + vec_size = FILE_SIZE / page_size; + if (FILE_SIZE % page_size) + vec_size++; + + vec = calloc(vec_size, sizeof(unsigned char)); + ASSERT_NE(NULL, vec) { + TH_LOG("Can't allocate array"); + } + + errno = 0; + fd = open(".", O_TMPFILE | O_RDWR, 0600); + ASSERT_NE(-1, fd) { + TH_LOG("Can't create temporary file: %s", + strerror(errno)); + } + errno = 0; + retval = fallocate(fd, 0, 0, FILE_SIZE); + ASSERT_EQ(0, retval) { + TH_LOG("Error allocating space for the temporary file: %s", + strerror(errno)); + } + + /* + * Map the whole file, the pages shouldn't be fetched yet. + */ + errno = 0; + addr = mmap(NULL, FILE_SIZE, PROT_READ | PROT_WRITE, + MAP_SHARED, fd, 0); + ASSERT_NE(MAP_FAILED, addr) { + TH_LOG("mmap error: %s", strerror(errno)); + } + retval = mincore(addr, FILE_SIZE, vec); + ASSERT_EQ(0, retval); + for (i = 0; i < vec_size; i++) { + ASSERT_EQ(0, vec[i]) { + TH_LOG("Unexpected page in memory"); + } + } + + /* + * Touch a page in the middle of the mapping. We expect the next + * few pages (the readahead window) to be populated too. + */ + addr[FILE_SIZE / 2] = 1; + retval = mincore(addr, FILE_SIZE, vec); + ASSERT_EQ(0, retval); + ASSERT_EQ(1, vec[FILE_SIZE / 2 / page_size]) { + TH_LOG("Page not found in memory after use"); + } + + i = FILE_SIZE / 2 / page_size + 1; + while (i < vec_size && vec[i]) { + ra_pages++; + i++; + } + EXPECT_GT(ra_pages, 0) { + TH_LOG("No read-ahead pages found in memory"); + } + + EXPECT_LT(i, vec_size) { + TH_LOG("Read-ahead pages reached the end of the file"); + } + /* + * End of the readahead window. The rest of the pages shouldn't + * be in memory. + */ + if (i < vec_size) { + while (i < vec_size && !vec[i]) + i++; + EXPECT_EQ(vec_size, i) { + TH_LOG("Unexpected page in memory beyond readahead window"); + } + } + + munmap(addr, FILE_SIZE); + close(fd); + free(vec); +} + + +/* + * Test mincore() behavior on a page backed by a tmpfs file. This test + * performs the same steps as the previous one. However, we don't expect + * any readahead in this case. + */ +TEST(check_tmpfs_mmap) +{ + unsigned char *vec; + int vec_size; + char *addr; + int retval; + int page_size; + int fd; + int i; + int ra_pages = 0; + + page_size = sysconf(_SC_PAGESIZE); + vec_size = FILE_SIZE / page_size; + if (FILE_SIZE % page_size) + vec_size++; + + vec = calloc(vec_size, sizeof(unsigned char)); + ASSERT_NE(NULL, vec) { + TH_LOG("Can't allocate array"); + } + + errno = 0; + fd = open("/dev/shm", O_TMPFILE | O_RDWR, 0600); + ASSERT_NE(-1, fd) { + TH_LOG("Can't create temporary file: %s", + strerror(errno)); + } + errno = 0; + retval = fallocate(fd, 0, 0, FILE_SIZE); + ASSERT_EQ(0, retval) { + TH_LOG("Error allocating space for the temporary file: %s", + strerror(errno)); + } + + /* + * Map the whole file, the pages shouldn't be fetched yet. + */ + errno = 0; + addr = mmap(NULL, FILE_SIZE, PROT_READ | PROT_WRITE, + MAP_SHARED, fd, 0); + ASSERT_NE(MAP_FAILED, addr) { + TH_LOG("mmap error: %s", strerror(errno)); + } + retval = mincore(addr, FILE_SIZE, vec); + ASSERT_EQ(0, retval); + for (i = 0; i < vec_size; i++) { + ASSERT_EQ(0, vec[i]) { + TH_LOG("Unexpected page in memory"); + } + } + + /* + * Touch a page in the middle of the mapping. We expect only + * that page to be fetched into memory. + */ + addr[FILE_SIZE / 2] = 1; + retval = mincore(addr, FILE_SIZE, vec); + ASSERT_EQ(0, retval); + ASSERT_EQ(1, vec[FILE_SIZE / 2 / page_size]) { + TH_LOG("Page not found in memory after use"); + } + + i = FILE_SIZE / 2 / page_size + 1; + while (i < vec_size && vec[i]) { + ra_pages++; + i++; + } + ASSERT_EQ(ra_pages, 0) { + TH_LOG("Read-ahead pages found in memory"); + } + + munmap(addr, FILE_SIZE); + close(fd); + free(vec); +} + +TEST_HARNESS_MAIN -- cgit v1.2.3