perf tools: Document parameterized and symbolic events

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Cody P Schafer <dev@codyps.com>
Cc: Haren Myneni <hbabu@us.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1420679633-28856-5-git-send-email-sukadev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 29ee857..04e150d 100644
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -25,10 +25,22 @@
 
 -e::
 --event=::
-	Select the PMU event. Selection can be a symbolic event name
-	(use 'perf list' to list all events) or a raw PMU
-	event (eventsel+umask) in the form of rNNN where NNN is a
-	 hexadecimal event descriptor.
+	Select the PMU event. Selection can be:
+
+	- a symbolic event name (use 'perf list' to list all events)
+
+	- a raw PMU event (eventsel+umask) in the form of rNNN where NNN is a
+	  hexadecimal event descriptor.
+
+	- a symbolically formed event like 'pmu/param1=0x3,param2/' where
+	  param1 and param2 are defined as formats for the PMU in
+	  /sys/bus/event_sources/devices/<pmu>/format/*
+
+	- a symbolically formed event like 'pmu/config=M,config1=N,config2=K/'
+	  where M, N, K are numbers (in decimal, hex, octal format).
+	  Acceptable values for each of 'config', 'config1' and 'config2'
+	  parameters are defined by corresponding entries in
+	  /sys/bus/event_sources/devices/<pmu>/format/*
 
 -i::
 --no-inherit::