Messages in this thread Patch in this message |  | | Date | Thu, 5 Dec 2013 10:50:39 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 4/4] perf trace: Add option to specify machine type |
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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 <dsahern@gmail.com> > Cc: Ingo Molnar <mingo@kernel.org> > Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> > Cc: Frederic Weisbecker <fweisbec@gmail.com> > Cc: Jiri Olsa <jolsa@redhat.com> > Cc: Namhyung Kim <namhyung@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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