Em Fri, Jun 16, 2017 at 02:12:53PM +0200, Jiri Olsa escreveu:
> Ingo reported following warning flooding the report out:
>
> unwind: target platform=x86 is not supported
>
> We trigger this warning when the dwarf unwinder is asked to
> process architecture which wasn't compiled in, like when you
> get 32bit application samples on your 64bit server and you
> don't have the 32bit remote unwind support compiled in.
>
> This patch limits the warning to single message for arch,
> and adds bits info. Above message is changed to:
>
> unwind: target platform=x86 32bit is not supported
Can we have a more informative message telling the user what is
necessary to have this feature supported?
The way you phrased it looks like it is not supported at all, while what
I read in the discussion is that one needs to have specific versions of
support libraries installed to have this working, right?
- Arnaldo
> Cc: He Kuang <heku...@huawei.com>
> Signed-off-by: Jiri Olsa <jo...@kernel.org>
> ---
> tools/perf/util/unwind-libunwind.c | 29 ++++++++++++++++++++++++-----
> 1 file changed, 24 insertions(+), 5 deletions(-)
>
> diff --git a/tools/perf/util/unwind-libunwind.c
> b/tools/perf/util/unwind-libunwind.c
> index 6d542a4e0648..1439a6bcfa07 100644
> --- a/tools/perf/util/unwind-libunwind.c
> +++ b/tools/perf/util/unwind-libunwind.c
> @@ -1,12 +1,24 @@
> +#include <linux/err.h>
> #include "unwind.h"
> #include "thread.h"
> #include "session.h"
> #include "debug.h"
> #include "arch/common.h"
>
> -struct unwind_libunwind_ops __weak *local_unwind_libunwind_ops;
> -struct unwind_libunwind_ops __weak *x86_32_unwind_libunwind_ops;
> -struct unwind_libunwind_ops __weak *arm64_unwind_libunwind_ops;
> +enum {
> + ERR_LOCAL = 0,
> + ERR_X86_32 = 1,
> + ERR_ARM64 = 2,
> +};
> +
> +/*
> + * Set default error values, so we can warn appropriately when
> + * the support is not compiled in. Using negative values so we
> + * can use ERR macros.
> + */
> +struct unwind_libunwind_ops __weak *local_unwind_libunwind_ops = (void *)
> -ERR_LOCAL;
> +struct unwind_libunwind_ops __weak *x86_32_unwind_libunwind_ops = (void *)
> -ERR_X86_32;
> +struct unwind_libunwind_ops __weak *arm64_unwind_libunwind_ops = (void *)
> -ERR_ARM64;
>
> static void unwind__register_ops(struct thread *thread,
> struct unwind_libunwind_ops *ops)
> @@ -48,8 +60,15 @@ int unwind__prepare_access(struct thread *thread, struct
> map *map,
> ops = arm64_unwind_libunwind_ops;
> }
>
> - if (!ops) {
> - pr_err("unwind: target platform=%s is not supported\n", arch);
> + if (IS_ERR(ops)) {
> + static unsigned long warned;
> + long bit = -PTR_ERR(ops);
> +
> + if (!test_and_set_bit(bit, &warned)) {
> + pr_err("unwind: target platform=%s %dbit is not
> supported\n",
> + arch, dso_type == DSO__TYPE_64BIT ? 64 : 32);
> + }
> +
> return -1;
> }
> out_register:
> --
> 2.9.4
