On Tue, Aug 18, 2026 at 6:44 PM Leon Hwang <[email protected]> wrote: > > On 19/8/26 00:15, [email protected] wrote: > >> diff --git a/tools/testing/selftests/bpf/prog_tests/global_data_init.c > >> b/tools/testing/selftests/bpf/prog_tests/global_data_init.c > >> index 5671c31085cd..2b69290bcc3e 100644 > >> --- a/tools/testing/selftests/bpf/prog_tests/global_data_init.c > >> +++ b/tools/testing/selftests/bpf/prog_tests/global_data_init.c > > > > [ ... ] > > > >> @@ -236,6 +223,57 @@ static void test_global_percpu_data_lskel(void) > >> test_global_percpu_data_lskel__destroy(lskel); > >> } > >> > >> +#define PAGE_SIZE 4096 > >> + > >> +static void test_global_percpu_data_map_resize(void) > >> +{ > >> + const __u32 desired_sz = sysconf(_SC_PAGE_SIZE) * 2; > >> + struct test_global_percpu_data *skel; > >> + const int arr_value = -1; > >> + struct bpf_map *map; > >> + int err, prog_fd; > >> + size_t data_sz; > >> + > >> + if (sysconf(_SC_PAGE_SIZE) != PAGE_SIZE) { > >> + test__skip(); > >> + return; > >> + } > >> + > >> + skel = test_global_percpu_data__open(); > >> + if (!ASSERT_OK_PTR(skel, "test_global_percpu_data__open")) > >> + return; > >> + > >> + map = skel->maps.percpu_arr; > >> + skel->percpu_arr->arr[0] = arr_value; > >> + err = bpf_map__set_value_size(map, desired_sz); > > > > This isn't a bug, but since the guard above already pins the page size to > > 4096, would `const __u32 desired_sz = PAGE_SIZE * 2;` read more directly > > Will change to 'PAGE_SIZE * 2' if the next revision is needed. > > > here - and is the unguarded `#define PAGE_SIZE 4096` preferable to the > > `#ifndef PAGE_SIZE` form used in sockopt.c? > > No. PAGE_SIZE must be 4096 here. >
can you please elaborate why do we care about specific PAGE_SIZE value? it's a bit weird to guard test based on page size... > > > >> + if (!ASSERT_OK(err, "bpf_map__set_value_size")) > >> + goto out; > >> + if (!ASSERT_EQ(bpf_map__value_size(map), desired_sz, > >> "bpf_map__value_size")) > >> + goto out; > >> + if (!ASSERT_NEQ(bpf_map__btf_value_type_id(map), 0, > >> "bpf_map__btf_value_type_id")) > >> + goto out; > >> + > >> + skel->percpu_arr = bpf_map__initial_value(map, &data_sz); > >> + if (!ASSERT_EQ(data_sz, desired_sz, "data_sz")) > >> + goto out; > >> + if (!ASSERT_OK_PTR(skel->percpu_arr, "skel->percpu_arr")) > >> + goto out; > > > > This isn't a bug, but would it read more consistently with > > test_global_percpu_data_init() to check ASSERT_OK_PTR(skel->percpu_arr) > > before ASSERT_EQ(data_sz, desired_sz)? The block this replaces checked > > pointer-then-size, and the surviving test_global_percpu_data_init() at the > > same file still does pointer-then-size. > > Unnecessary to keep consistent for their order. This is a really minor > readability concern. > > Thanks, > Leon >
