On Mon, Nov 17, 2025 at 8:22 AM Leon Hwang <[email protected]> wrote: > > Add test coverage for the new BPF_F_CPU and BPF_F_ALL_CPUS flags support > in percpu maps. The following APIs are exercised: > > * bpf_map_update_batch() > * bpf_map_lookup_batch() > * bpf_map_update_elem() > * bpf_map__update_elem() > * bpf_map_lookup_elem_flags() > * bpf_map__lookup_elem() > > Add tests to verify that array and hash maps do not support BPF_F_CPU > and BPF_F_ALL_CPUS flags. > > Signed-off-by: Leon Hwang <[email protected]> > --- > .../selftests/bpf/prog_tests/percpu_alloc.c | 312 ++++++++++++++++++ > .../selftests/bpf/progs/percpu_alloc_array.c | 32 ++ > 2 files changed, 344 insertions(+) > > diff --git a/tools/testing/selftests/bpf/prog_tests/percpu_alloc.c > b/tools/testing/selftests/bpf/prog_tests/percpu_alloc.c > index 343da65864d6d..b9c3f5f6cd9c3 100644 > --- a/tools/testing/selftests/bpf/prog_tests/percpu_alloc.c > +++ b/tools/testing/selftests/bpf/prog_tests/percpu_alloc.c > @@ -1,5 +1,6 @@ > // SPDX-License-Identifier: GPL-2.0 > #include <test_progs.h> > +#include "cgroup_helpers.h" > #include "percpu_alloc_array.skel.h" > #include "percpu_alloc_cgrp_local_storage.skel.h" > #include "percpu_alloc_fail.skel.h" > @@ -115,6 +116,305 @@ static void test_failure(void) { > RUN_TESTS(percpu_alloc_fail); > } > > +static void test_percpu_map_op_cpu_flag(struct bpf_map *map, void *keys, > size_t key_sz, > + u32 max_entries, bool test_batch) > +{ > + size_t value_sz = sizeof(u32), value_sz_cpus, value_sz_total; > + u32 *values = NULL, *values_percpu = NULL; > + int i, j, cpu, map_fd, nr_cpus, err; > + const u32 value = 0xDEADC0DE; > + u32 count = max_entries, v; > + u64 batch = 0, flags; > + void *values_row; > + LIBBPF_OPTS(bpf_map_batch_opts, batch_opts); > + > + nr_cpus = libbpf_num_possible_cpus(); > + if (!ASSERT_GT(nr_cpus, 0, "libbpf_num_possible_cpus")) > + return; > + > + value_sz_cpus = value_sz * nr_cpus; > + values = calloc(max_entries, value_sz_cpus); > + if (!ASSERT_OK_PTR(values, "calloc values")) > + return; > + > + values_percpu = calloc(max_entries, roundup(value_sz, 8) * nr_cpus); > + if (!ASSERT_OK_PTR(values_percpu, "calloc values_percpu")) { > + free(values); > + return; > + } > + > + value_sz_total = value_sz_cpus * max_entries; > + memset(values, 0, value_sz_total); > + > + map_fd = bpf_map__fd(map); > + flags = BPF_F_CPU | BPF_F_ALL_CPUS; > + err = bpf_map_lookup_elem_flags(map_fd, keys, values, flags); > + if (!ASSERT_ERR(err, "bpf_map_lookup_elem_flags cpu|all_cpus")) > + goto out; > + > + err = bpf_map_update_elem(map_fd, keys, values, flags); > + if (!ASSERT_ERR(err, "bpf_map_update_elem cpu|all_cpus")) > + goto out; > + > + flags = BPF_F_ALL_CPUS; > + err = bpf_map_lookup_elem_flags(map_fd, keys, values, flags); > + if (!ASSERT_ERR(err, "bpf_map_lookup_elem_flags all_cpus")) > + goto out; > + > + flags = BPF_F_LOCK | BPF_F_CPU; > + err = bpf_map_lookup_elem_flags(map_fd, keys, values, flags); > + if (!ASSERT_ERR(err, "bpf_map_lookup_elem_flags BPF_F_LOCK")) > + goto out; > + > + flags = BPF_F_LOCK | BPF_F_ALL_CPUS; > + err = bpf_map_update_elem(map_fd, keys, values, flags); > + if (!ASSERT_ERR(err, "bpf_map_update_elem BPF_F_LOCK")) > + goto out; > + > + flags = (u64)nr_cpus << 32 | BPF_F_CPU; > + err = bpf_map_update_elem(map_fd, keys, values, flags); > + if (!ASSERT_EQ(err, -ERANGE, "bpf_map_update_elem -ERANGE")) > + goto out; > + > + err = bpf_map__update_elem(map, keys, key_sz, values, value_sz, > flags); > + if (!ASSERT_EQ(err, -ERANGE, "bpf_map__update_elem -ERANGE")) > + goto out; > + > + err = bpf_map_lookup_elem_flags(map_fd, keys, values, flags); > + if (!ASSERT_EQ(err, -ERANGE, "bpf_map_lookup_elem_flags -ERANGE")) > + goto out; > + > + err = bpf_map__lookup_elem(map, keys, key_sz, values, value_sz, > flags); > + if (!ASSERT_EQ(err, -ERANGE, "bpf_map__lookup_elem -ERANGE")) > + goto out; > + > + for (cpu = 0; cpu < nr_cpus; cpu++) { > + /* clear value on all cpus */ > + values[0] = 0; > + flags = BPF_F_ALL_CPUS; > + for (i = 0; i < max_entries; i++) { > + err = bpf_map__update_elem(map, keys + i * key_sz, > key_sz, values, > + value_sz, flags); > + if (!ASSERT_OK(err, "bpf_map__update_elem all_cpus")) > + goto out; > + } > + > + /* update value on specified cpu */ > + for (i = 0; i < max_entries; i++) { > + values[0] = value; > + flags = (u64)cpu << 32 | BPF_F_CPU; > + err = bpf_map__update_elem(map, keys + i * key_sz, > key_sz, values, > + value_sz, flags); > + if (!ASSERT_OK(err, "bpf_map__update_elem specified > cpu")) > + goto out; > + > + /* lookup then check value on CPUs */ > + for (j = 0; j < nr_cpus; j++) { > + flags = (u64)j << 32 | BPF_F_CPU; > + err = bpf_map__lookup_elem(map, keys + i * > key_sz, key_sz, values, > + value_sz, flags); > + if (!ASSERT_OK(err, "bpf_map__lookup_elem > specified cpu")) > + goto out; > + if (!ASSERT_EQ(values[0], j != cpu ? 0 : > value, > + "bpf_map__lookup_elem value on > specified cpu")) > + goto out;
I was about to apply it, but noticed that the test is unstable. It fails 1 out of 10 for me in the above line. test_percpu_map_op_cpu_flag:PASS:bpf_map_lookup_batch value on specified cpu 0 nsec test_percpu_map_op_cpu_flag:FAIL:bpf_map_lookup_batch value on specified cpu unexpected bpf_map_lookup_batch value on specified cpu: actual 0 != expected 3735929054 #261/15 percpu_alloc/cpu_flag_lru_percpu_hash:FAIL #261 percpu_alloc:FAIL Please investigate what is going on. pw-bot: cr
