Em Mon, Jan 25, 2016 at 09:56:15AM +0000, Wang Nan escreveu:
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
>
> +static int record__synthesize(struct record *rec)
> +{
> + struct perf_session *session = rec->session;
> + struct machine *machine = &session->machines.host;
> + struct perf_data_file *file = &rec->file;
> + struct record_opts *opts = &rec->opts;
> + struct perf_tool *tool = &rec->tool;
> + int fd = perf_data_file__fd(file);
> + int err = 0;
> + static bool warned_kmaps = false, warned_modules = false;
snip
> + err = perf_event__synthesize_kernel_mmap(tool,
> process_synthesized_event,
> + machine);
> + if (err < 0 && !warned_kmaps) {
Please use WARN_ONCE, there are lots of examples in tools/perf and in
the kernel proper, from where this idiom was adopted, this way these
static variables will be auto-created.
- Arnaldo
> + warned_kmaps = true;
> + pr_err("Couldn't record kernel reference relocation symbol\n"
> + "Symbol resolution may be skewed if relocation was used
> (e.g. kexec).\n"
> + "Check /proc/kallsyms permission or run as root.\n");
> + }
> +
> + err = perf_event__synthesize_modules(tool, process_synthesized_event,
> + machine);
> + if (err < 0 && !warned_modules) {
> + warned_modules = true;
> + pr_err("Couldn't record kernel module information.\n"
> + "Symbol resolution may be skewed if relocation was used
> (e.g. kexec).\n"
> + "Check /proc/modules permission or run as root.\n");
