Re: [PATCH bpf-next v9 9/9] selftests/bpf: Add tests to verify map create failure log

[Alexei Starovoitov]

On Wed, Feb 4, 2026 at 7:54 PM Leon Hwang <leon.hwang@xxxxxxxxx> wrote:
>
>
>
> On 5/2/26 04:14, Alexei Starovoitov wrote:
> > On Mon, Feb 2, 2026 at 6:43 AM Leon Hwang <leon.hwang@xxxxxxxxx> wrote:
> >>
> >> +
> >> +#define BPF_LOG_FIXED  8
> >> +
> >> +static void test_map_create(enum bpf_map_type map_type, const char *map_name,
> >> +                           struct bpf_map_create_opts *opts, const char *exp_msg)
> >> +{
> >> +       const int key_size = 4, value_size = 4, max_entries = 1;
> >> +       char log_buf[128];
> >> +       int fd;
> >> +       LIBBPF_OPTS(bpf_log_opts, log_opts);
> >> +
> >> +       log_buf[0] = '\0';
> >> +       log_opts.log_buf = log_buf;
> >> +       log_opts.log_size = sizeof(log_buf);
> >> +       log_opts.log_level = BPF_LOG_FIXED;
> >
> > Why? Which part of the test needs the log with this flag?
>
> BPF_LOG_FIXED looks odd here.
>
> This test sets 'log_level = BPF_LOG_FIXED' to match the behavior of
> bpf_vlog_init() as initialized by bpf_log_attr_create_vlog() in
> patch #7. BPF_LOG_FIXED is intended to be the default log_level
> there.

I don't think you answered my question.
bpf_vlog_init() is using whatever log_level user space provided.
Why do you pass BPF_LOG_FIXED ?