Add a psi struct ops test. The test creates a cgroup with two child sub-cgroups, sets up memory.high for one of those and puts there a memory hungry process (initially frozen). Then it creates 2 psi triggers from within a init() bpf callback and attaches them to these cgroups. Then it deletes the first cgroup and runs the memory hungry task. The task is creating a high memory pressure, which triggers the psi event. The psi bpf handler declares a memcg oom in the corresponding cgroup. Finally the checks that both handle_cgroup_free() and handle_psi_event() handlers were executed, the correct process was killed and oom counters were updated. Signed-off-by: Roman Gushchin --- .../selftests/bpf/prog_tests/test_psi.c | 224 ++++++++++++++++++ tools/testing/selftests/bpf/progs/test_psi.c | 76 ++++++ 2 files changed, 300 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/test_psi.c create mode 100644 tools/testing/selftests/bpf/progs/test_psi.c diff --git a/tools/testing/selftests/bpf/prog_tests/test_psi.c b/tools/testing/selftests/bpf/prog_tests/test_psi.c new file mode 100644 index 000000000000..4f3c91bd6606 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/test_psi.c @@ -0,0 +1,224 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include + +#include "cgroup_helpers.h" +#include "test_psi.skel.h" + +enum psi_res { + PSI_IO, + PSI_MEM, + PSI_CPU, + PSI_IRQ, + NR_PSI_RESOURCES, +}; + +struct cgroup_desc { + const char *path; + unsigned long long id; + int pid; + int fd; + size_t target; + size_t high; + bool victim; +}; + +#define MB (1024 * 1024) + +static struct cgroup_desc cgroups[] = { + { .path = "/oom_test" }, + { .path = "/oom_test/cg1" }, + { .path = "/oom_test/cg2", .target = 500 * MB, + .high = 40 * MB, .victim = true }, +}; + +static int spawn_task(struct cgroup_desc *desc) +{ + char *ptr; + int pid; + + pid = fork(); + if (pid < 0) + return pid; + + if (pid > 0) { + /* parent */ + desc->pid = pid; + return 0; + } + + /* child */ + ptr = (char *)malloc(desc->target); + if (!ptr) + return -ENOMEM; + + memset(ptr, 'a', desc->target); + + while (1) + sleep(1000); + + return 0; +} + +static void setup_environment(void) +{ + int i, err; + + err = setup_cgroup_environment(); + if (!ASSERT_OK(err, "setup_cgroup_environment")) + goto cleanup; + + for (i = 0; i < ARRAY_SIZE(cgroups); i++) { + cgroups[i].fd = create_and_get_cgroup(cgroups[i].path); + if (!ASSERT_GE(cgroups[i].fd, 0, "create_and_get_cgroup")) + goto cleanup; + + cgroups[i].id = get_cgroup_id(cgroups[i].path); + if (!ASSERT_GT(cgroups[i].id, 0, "get_cgroup_id")) + goto cleanup; + + /* Freeze the top-level cgroup and enable the memory controller */ + if (i == 0) { + err = write_cgroup_file(cgroups[i].path, "cgroup.freeze", "1"); + if (!ASSERT_OK(err, "freeze cgroup")) + goto cleanup; + + err = write_cgroup_file(cgroups[i].path, "cgroup.subtree_control", + "+memory"); + if (!ASSERT_OK(err, "enable memory controller")) + goto cleanup; + } + + /* Set memory.high */ + if (cgroups[i].high) { + char buf[256]; + + snprintf(buf, sizeof(buf), "%lu", cgroups[i].high); + err = write_cgroup_file(cgroups[i].path, "memory.high", buf); + if (!ASSERT_OK(err, "set memory.high")) + goto cleanup; + + snprintf(buf, sizeof(buf), "0"); + write_cgroup_file(cgroups[i].path, "memory.swap.max", buf); + } + + /* Spawn tasks creating memory pressure */ + if (cgroups[i].target) { + char buf[256]; + + err = spawn_task(&cgroups[i]); + if (!ASSERT_OK(err, "spawn task")) + goto cleanup; + + snprintf(buf, sizeof(buf), "%d", cgroups[i].pid); + err = write_cgroup_file(cgroups[i].path, "cgroup.procs", buf); + if (!ASSERT_OK(err, "put child into a cgroup")) + goto cleanup; + } + } + + return; + +cleanup: + cleanup_cgroup_environment(); +} + +static int run_and_wait_for_oom(void) +{ + int ret = -1; + bool first = true; + char buf[4096] = {}; + size_t size; + + /* Unfreeze the top-level cgroup */ + ret = write_cgroup_file(cgroups[0].path, "cgroup.freeze", "0"); + if (!ASSERT_OK(ret, "unfreeze cgroup")) + return -1; + + for (;;) { + int i, status; + pid_t pid = wait(&status); + + if (pid == -1) { + if (errno == EINTR) + continue; + /* ECHILD */ + break; + } + + if (!first) + continue; + first = false; + + /* Check which process was terminated first */ + for (i = 0; i < ARRAY_SIZE(cgroups); i++) { + if (!ASSERT_OK(cgroups[i].victim != + (pid == cgroups[i].pid), + "correct process was killed")) { + ret = -1; + break; + } + + if (!cgroups[i].victim) + continue; + + /* Check the memcg oom counter */ + size = read_cgroup_file(cgroups[i].path, "memory.events", + buf, sizeof(buf)); + if (!ASSERT_OK(size <= 0, "read memory.events")) { + ret = -1; + break; + } + + if (!ASSERT_OK(strstr(buf, "oom_kill 1") == NULL, + "oom_kill count check")) { + ret = -1; + break; + } + } + + /* Kill all remaining tasks */ + for (i = 0; i < ARRAY_SIZE(cgroups); i++) + if (cgroups[i].pid && cgroups[i].pid != pid) + kill(cgroups[i].pid, SIGKILL); + } + + return ret; +} + +void test_psi(void) +{ + struct test_psi *skel; + u64 freed_cgroup_id; + int err; + + setup_environment(); + + skel = test_psi__open_and_load(); + err = libbpf_get_error(skel); + if (CHECK_FAIL(err)) + goto cleanup; + + skel->bss->deleted_cgroup_id = cgroups[1].id; + skel->bss->high_pressure_cgroup_id = cgroups[2].id; + + err = test_psi__attach(skel); + if (CHECK_FAIL(err)) + goto cleanup; + + /* Delete the first cgroup, it should trigger handle_cgroup_free() */ + remove_cgroup(cgroups[1].path); + + /* Unfreeze all child tasks and create the memory pressure */ + err = run_and_wait_for_oom(); + CHECK_FAIL(err); + + /* Check the result of the handle_cgroup_free() handler */ + freed_cgroup_id = skel->bss->deleted_cgroup_id; + ASSERT_EQ(freed_cgroup_id, cgroups[1].id, "freed cgroup id"); + +cleanup: + cleanup_cgroup_environment(); + test_psi__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_psi.c b/tools/testing/selftests/bpf/progs/test_psi.c new file mode 100644 index 000000000000..2c36c05a3065 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_psi.c @@ -0,0 +1,76 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include "vmlinux.h" +#include +#include + +char _license[] SEC("license") = "GPL"; + +struct mem_cgroup *bpf_get_mem_cgroup(struct cgroup_subsys_state *css) __ksym; +void bpf_put_mem_cgroup(struct mem_cgroup *memcg) __ksym; +int bpf_out_of_memory(struct mem_cgroup *memcg, int order, bool wait_on_oom_lock, + const char *constraint_text__nullable) __ksym; +int bpf_psi_create_trigger(struct bpf_psi *bpf_psi, u64 cgroup_id, + u32 res, u32 threshold_us, u32 window_us) __ksym; + +#define PSI_FULL 0x80000000 + +/* cgroup which will experience the high memory pressure */ +u64 high_pressure_cgroup_id; + +/* cgroup which will be deleted */ +u64 deleted_cgroup_id; + +/* cgroup which was actually freed */ +u64 freed_cgroup_id; + +char constraint_name[] = "CONSTRAINT_BPF_PSI_MEM"; + +SEC("struct_ops.s/init") +int BPF_PROG(psi_init, struct bpf_psi *bpf_psi) +{ + int ret; + + ret = bpf_psi_create_trigger(bpf_psi, high_pressure_cgroup_id, + PSI_MEM | PSI_FULL, 100000, 1000000); + if (ret) + return ret; + + return bpf_psi_create_trigger(bpf_psi, deleted_cgroup_id, + PSI_IO, 100000, 1000000); +} + +SEC("struct_ops.s/handle_psi_event") +void BPF_PROG(handle_psi_event, struct psi_trigger *t) +{ + u64 cgroup_id = t->cgroup_id; + struct mem_cgroup *memcg; + struct cgroup *cgroup; + + cgroup = bpf_cgroup_from_id(cgroup_id); + if (!cgroup) + return; + + memcg = bpf_get_mem_cgroup(&cgroup->self); + if (!memcg) { + bpf_cgroup_release(cgroup); + return; + } + + bpf_out_of_memory(memcg, 0, true, constraint_name); + + bpf_put_mem_cgroup(memcg); + bpf_cgroup_release(cgroup); +} + +SEC("struct_ops.s/handle_cgroup_free") +void BPF_PROG(handle_cgroup_free, u64 cgroup_id) +{ + freed_cgroup_id = cgroup_id; +} + +SEC(".struct_ops.link") +struct bpf_psi_ops test_bpf_psi = { + .init = (void *)psi_init, + .handle_psi_event = (void *)handle_psi_event, + .handle_cgroup_free = (void *)handle_cgroup_free, +}; -- 2.50.1