Em Wed, Dec 04, 2013 at 07:41:42PM -0700, David Ahern escreveu:
> Perhaps there is a better way to do this; I could not think of one and
> I don't see any field in the tracepoint that can be leveraged. So ...
>
> perf-trace autodetects the machine type (e.g., i386, x86_64, etc) via
> libaudit.
And that means that using perf.data files from another machine, say,
ARM, will produce completely bogus results :-\
We need a way to store this info in the perf.data header, i.e. use the
same algorithm that libaudit uses in audit_detect_machine() (and set the
open_id as well, btw) at 'perf record' time and store it somewhere.
What we have now that could be used?
Lets see:
[acme@zoo linux]$ perf report | grep 'arch'
# arch : x86_64
[acme@zoo linux]$
Would that be enough? Stephane?
- Arnaldo
> When running 32-bit apps on a 64-bit kernel the wrong machine
> type is used to convert syscall numbers to names leading to wrong information
> getting displayed to the user. This option allows the user to override
> the machine type to use.
>
> Signed-off-by: David Ahern <dsah...@gmail.com>
> Cc: Ingo Molnar <mi...@kernel.org>
> Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
> Cc: Frederic Weisbecker <fweis...@gmail.com>
> Cc: Jiri Olsa <jo...@redhat.com>
> Cc: Namhyung Kim <namhy...@kernel.org>
> ---
> tools/perf/builtin-trace.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
> index 0203324fe585..4a78a39b684a 100644
> --- a/tools/perf/builtin-trace.c
> +++ b/tools/perf/builtin-trace.c
> @@ -2274,6 +2274,7 @@ int cmd_trace(int argc, const char **argv, const char
> *prefix __maybe_unused)
> };
> const char *output_name = NULL;
> const char *ev_qualifier_str = NULL;
> + const char *machine_str = NULL;
> const struct option trace_options[] = {
> OPT_BOOLEAN(0, "comm", &trace.show_comm,
> "show the thread COMM next to its id"),
> @@ -2308,6 +2309,8 @@ int cmd_trace(int argc, const char **argv, const char
> *prefix __maybe_unused)
> "Show only syscall summary with statistics"),
> OPT_BOOLEAN('S', "with-summary", &trace.summary,
> "Show all syscalls and summary with statistics"),
> + OPT_STRING('M', NULL, &machine_str, "x86|x86_64",
> + "Advanced: machine type for converting system calls: x86,
> x86_64"),
> OPT_END()
> };
> int err;
> @@ -2318,6 +2321,17 @@ int cmd_trace(int argc, const char **argv, const char
> *prefix __maybe_unused)
>
> argc = parse_options(argc, argv, trace_options, trace_usage, 0);
>
> + if (machine_str) {
> + if (strcmp(machine_str, "x86") == 0)
> + trace.audit.machine = MACH_X86;
> + else if (strcmp(machine_str, "x86_64") == 0)
> + trace.audit.machine = MACH_86_64;
> + else {
> + pr_err("Invalid machine type\n");
> + return -EINVAL;
> + }
> + }
> +
> /* summary_only implies summary option, but don't overwrite summary if
> set */
> if (trace.summary_only)
> trace.summary = trace.summary_only;
> --
> 1.8.3.4 (Apple Git-47)
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