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DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1769481975; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VXv6g7uPf7qxRkkIiMBqCwgrrYFAEGJ5DOUNMycRfvU=; b=GKEdwOF6C3Mk469brs7wCG8M6vexvZC8GeGdIk5y8J9fSliXRiLQvf9qXcrBfqw+shmBOi sCo4oW3bBHSkLZnwIhro3QagwKL9z04keACu+/jphZ7u4EVEKzJk4fE0C8CYat8xniqq5S smCemBHDBexxL9q8cWq06X2bDN8qSkM= From: Roman Gushchin To: bpf@vger.kernel.org Cc: Michal Hocko , Alexei Starovoitov , Matt Bobrowski , Shakeel Butt , JP Kobryn , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Suren Baghdasaryan , Johannes Weiner , Andrew Morton , Roman Gushchin Subject: [PATCH bpf-next v3 17/17] bpf: selftests: PSI struct ops test Date: Mon, 26 Jan 2026 18:46:04 -0800 Message-ID: <20260127024604.495018-2-roman.gushchin@linux.dev> In-Reply-To: <20260127024604.495018-1-roman.gushchin@linux.dev> References: <20260127024604.495018-1-roman.gushchin@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 5D0E020002 X-Stat-Signature: yahnuokdix67pmhfkn4tdqg5hkqu5d1h X-HE-Tag: 1769481976-279647 X-HE-Meta: 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 oEpJ9zcW 2kcnJaV0NurgpxKJGhq6nywI5txxhRMpiElLHPg0MOx4qhdsP9Fg5blA0+OlmXzCLV+9s5tsN4qDa9pThvgck9z0L1IgOeQHKOQqbde+GSKgom/VnXjmUbo+07D27yRfbSSzqz9Swz2Rx58mtjZ3x4DaMJ4kaoBLQoGgEcoEjd5pwStT0qTqLIakZz+MZaIZpGRv3UcodppgckxA= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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). The memory hungry task is creating a high memory pressure in one memory cgroup, which triggers a PSI event. The PSI BPF handler declares a memcg oom in the corresponding cgroup. Signed-off-by: Roman Gushchin --- .../selftests/bpf/prog_tests/test_psi.c | 225 ++++++++++++++++++ tools/testing/selftests/bpf/progs/test_psi.c | 90 +++++++ 2 files changed, 315 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..170c6f6a1a35 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/test_psi.c @@ -0,0 +1,225 @@ +// 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 = "/psi_test" }, + { .path = "/psi_test/cg1" }, + { .path = "/psi_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) + _exit(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] = {}; + ssize_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; + int cgroup_fd; + int err; + + setup_environment(); + + skel = test_psi__open_and_load(); + if (!ASSERT_OK_PTR(skel, "open_and_load")) + goto cleanup; + + skel->bss->high_pressure_cgroup_id = cgroups[2].id; + skel->bss->my_pid = getpid(); + + err = test_psi__attach(skel); + if (CHECK_FAIL(err)) + goto cleanup; + + /* Delete the first cgroup, it used to trigger offline handler */ + remove_cgroup(cgroups[1].path); + + /* Create new cgroup */ + cgroup_fd = create_and_get_cgroup("/psi_test_new"); + if (!ASSERT_GT(cgroup_fd, 0, "create_and_get_cgroup")) + goto cleanup; + + /* Unfreeze all child tasks and create the memory pressure */ + err = run_and_wait_for_oom(); + CHECK_FAIL(err); + + close(cgroup_fd); +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..6efd5c995ce0 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_psi.c @@ -0,0 +1,90 @@ +#include "vmlinux.h" +#include "bpf_experimental.h" +#include +#include +#include + +char _license[] SEC("license") = "GPL"; + +/* cgroup which will experience the high memory pressure */ +u64 high_pressure_cgroup_id; +u32 my_pid = 0; + +/* last total full memory pressure value */ +u64 last_mem_full_total = 0; + +extern struct task_struct *bpf_task_from_pid(s32 pid) __ksym; +extern void bpf_task_release(struct task_struct *p) __ksym; + +struct elem { + struct bpf_task_work tw; +}; + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, int); + __type(value, struct elem); +} tw_map SEC(".maps"); + +static int psi_oom_work(struct bpf_map *map, void *key, void *value) +{ + struct cgroup *cgrp; + struct mem_cgroup *memcg; + + cgrp = bpf_cgroup_from_id(high_pressure_cgroup_id); + if (!cgrp) + return 0; + + memcg = bpf_get_mem_cgroup(&cgrp->self); + if (memcg) { + bpf_out_of_memory(memcg, 0, BPF_OOM_FLAGS_WAIT_ON_OOM_LOCK); + bpf_put_mem_cgroup(memcg); + } + + bpf_cgroup_release(cgrp); + return 0; +} + +static void schedule_oom_work(void) +{ + struct task_struct *task; + struct elem *val; + int key = 0; + + task = bpf_task_from_pid(my_pid); + if (task) { + val = bpf_map_lookup_elem(&tw_map, &key); + if (val) + bpf_task_work_schedule_signal(task, &val->tw, + &tw_map, psi_oom_work); + bpf_task_release(task); + } +} + +SEC("tp_btf/psi_avgs_work") +int BPF_PROG(psi_avgs, struct psi_group *group) +{ + u64 current_total; + u64 growth; + + /* Monitor only a single target cgroup */ + if (group->cgroup_id != high_pressure_cgroup_id) + return 0; + + /* Check for memory pressure */ + current_total = BPF_CORE_READ(group, total[PSI_MEM_FULL]); + if (last_mem_full_total == 0) { + last_mem_full_total = current_total; + return 0; + } + + growth = current_total - last_mem_full_total; + last_mem_full_total = current_total; + + /* Declare an OOM if growth > 50ms within the update period */ + if (growth > 50000000) + schedule_oom_work(); + + return 0; +} -- 2.52.0