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Commit 763122ad authored by Avi Kivity's avatar Avi Kivity Committed by Arnaldo Carvalho de Melo
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perf tools: Disable kernel symbol demangling by default 



Some Linux symbols (for example __vt_event_wait) are interpreted by the
demangler as C++ mangled names, which of course they aren't.

Disable kernel symbol demangling by default to avoid this, and allow
enabling it with a new option --demangle-kernel for those who wish it.

Reported-by: default avatarJiri Olsa <jolsa@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@cloudius-systems.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1410581705-26968-1-git-send-email-avi@cloudius-systems.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 29a3ce31

tools/perf/Documentation/perf-probe.txt

+3 −0
Original line number Diff line number Diff line
@@ -104,6 +104,9 @@ OPTIONS 
	Specify path to the executable or shared library file for user

	space tracing. Can also be used with --funcs option.



--demangle-kernel::

	Demangle kernel symbols.



In absence of -m/-x options, perf probe checks if the first argument after

the options is an absolute path name. If its an absolute path, perf probe

uses it as a target module/target user space binary to probe.

tools/perf/Documentation/perf-report.txt

+3 −0
Original line number Diff line number Diff line
@@ -276,6 +276,9 @@ OPTIONS 
	Demangle symbol names to human readable form. It's enabled by default,

	disable with --no-demangle.



--demangle-kernel::

	Demangle kernel symbol names to human readable form (for C++ kernels).



--mem-mode::

	Use the data addresses of samples in addition to instruction addresses

	to build the histograms.  To generate meaningful output, the perf.data

tools/perf/Documentation/perf-top.txt

+3 −0
Original line number Diff line number Diff line
@@ -98,6 +98,9 @@ Default is to monitor all CPUS. 
--hide_user_symbols::

        Hide user symbols.



--demangle-kernel::

        Demangle kernel symbols.



-D::

--dump-symtab::

        Dump the symbol table used for profiling.

tools/perf/builtin-probe.c

+2 −0
Original line number Diff line number Diff line
@@ -376,6 +376,8 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused) 
			"target executable name or path", opt_set_target),

	OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,

		    "Disable symbol demangling"),

	OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,

		    "Enable kernel symbol demangling"),

	OPT_END()

	};

	int ret;

tools/perf/builtin-report.c

+2 −0
Original line number Diff line number Diff line
@@ -680,6 +680,8 @@ int cmd_report(int argc, const char **argv, const char *prefix __maybe_unused) 
		   "objdump binary to use for disassembly and annotations"),

	OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,

		    "Disable symbol demangling"),

	OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,

		    "Enable kernel symbol demangling"),

	OPT_BOOLEAN(0, "mem-mode", &report.mem_mode, "mem access profile"),

	OPT_CALLBACK(0, "percent-limit", &report, "percent",

		     "Don't show entries under that percent", parse_percent_limit),