perf probe: Add variable filter support

Add filters support for available variable list.

Default filter is "!__k???tab_*&!__crc_*" for filtering out
automatically generated symbols.

The format of filter rule is "[!]GLOBPATTERN", so you can use wild
cards. If the filter rule starts with '!', matched variables are filter
out.

e.g.:
 # perf probe -V schedule --externs --filter=cpu*
Available variables at schedule
        @<schedule+0>
                cpumask_var_t   cpu_callout_mask
                cpumask_var_t   cpu_core_map
                cpumask_var_t   cpu_isolated_map
                cpumask_var_t   cpu_sibling_map
                int     cpu_number
                long unsigned int*      cpu_bit_bitmap
		...

Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Chase Douglas <chase.douglas@canonical.com>
Cc: Franck Bui-Huu <fbuihuu@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20110120141539.25915.43401.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
[ committer note: Removed the elf.h include as it was fixed up in e80711c]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt
index fcc51fe0195..32fb18f1695 100644
--- a/tools/perf/Documentation/perf-probe.txt
+++ b/tools/perf/Documentation/perf-probe.txt
@@ -77,6 +77,12 @@ OPTIONS
 --funcs::
 	Show available functions in given module or kernel.
 
+--filter=FILTER::
+	(Only for --vars) Set filter for variables. FILTER is a combination of
+	glob pattern, see FILTER PATTERN for details.
+	Default FILTER is "!__k???tab_* & !__crc_*".
+	If several filters are specified, only the last filter is valid.
+
 -f::
 --force::
 	Forcibly add events with existing name.
@@ -139,6 +145,14 @@ e.g.
 
 This provides some sort of flexibility and robustness to probe point definitions against minor code changes. For example, actual 10th line of schedule() can be moved easily by modifying schedule(), but the same line matching 'rq=cpu_rq*' may still exist in the function.)
 
+FILTER PATTERN
+--------------
+ The filter pattern is a glob matching pattern(s) to filter variables.
+ In addition, you can use "!" for specifying filter-out rule. You also can give several rules combined with "&" or "|", and fold those rules as one rule by using "(" ")".
+
+e.g.
+ With --filter "foo* | bar*", perf probe -V shows variables which start with "foo" or "bar".
+ With --filter "!foo* & *bar", perf probe -V shows variables which don't start with "foo" and end with "bar", like "fizzbar". But "foobar" is filtered out.
 
 EXAMPLES
 --------