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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-07 21:39:33 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-07 21:39:33 +0300 |
commit | 81e11336d97e7a4c25a65c302ef2bf9cd9808ed4 (patch) | |
tree | 44e069e0bb26068137a1bda7ca5125c5b068b4ab /tools/testing/selftests/cgroup/test_kmem.c | |
parent | 5631c5e0eb9035d92ceb20fcd9cdb7779a3f5cc7 (diff) | |
parent | 912c05720f00d039103d356a59c37dc7c3995e01 (diff) | |
download | linux-81e11336d97e7a4c25a65c302ef2bf9cd9808ed4.tar.xz |
Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
- a few MM hotfixes
- kthread, tools, scripts, ntfs and ocfs2
- some of MM
Subsystems affected by this patch series: kthread, tools, scripts, ntfs,
ocfs2 and mm (hofixes, pagealloc, slab-generic, slab, slub, kcsan,
debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, mincore,
sparsemem, vmalloc, kasan, pagealloc, hugetlb and vmscan).
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits)
mm: vmscan: consistent update to pgrefill
mm/vmscan.c: fix typo
khugepaged: khugepaged_test_exit() check mmget_still_valid()
khugepaged: retract_page_tables() remember to test exit
khugepaged: collapse_pte_mapped_thp() protect the pmd lock
khugepaged: collapse_pte_mapped_thp() flush the right range
mm/hugetlb: fix calculation of adjust_range_if_pmd_sharing_possible
mm: thp: replace HTTP links with HTTPS ones
mm/page_alloc: fix memalloc_nocma_{save/restore} APIs
mm/page_alloc.c: skip setting nodemask when we are in interrupt
mm/page_alloc: fallbacks at most has 3 elements
mm/page_alloc: silence a KASAN false positive
mm/page_alloc.c: remove unnecessary end_bitidx for [set|get]_pfnblock_flags_mask()
mm/page_alloc.c: simplify pageblock bitmap access
mm/page_alloc.c: extract the common part in pfn_to_bitidx()
mm/page_alloc.c: replace the definition of NR_MIGRATETYPE_BITS with PB_migratetype_bits
mm/shuffle: remove dynamic reconfiguration
mm/memory_hotplug: document why shuffle_zone() is relevant
mm/page_alloc: remove nr_free_pagecache_pages()
mm: remove vm_total_pages
...
Diffstat (limited to 'tools/testing/selftests/cgroup/test_kmem.c')
-rw-r--r-- | tools/testing/selftests/cgroup/test_kmem.c | 382 |
1 files changed, 382 insertions, 0 deletions
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 <linux/limits.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> +#include <sys/wait.h> +#include <errno.h> +#include <sys/sysinfo.h> +#include <pthread.h> + +#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; +} |