tracing/kprobes: Fix probe offset to be unsigned

[pandora-kernel.git] / Documentation / trace / kprobetrace.txt

diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt
index efff6eb..db55318 100644 (file)
--- a/Documentation/trace/kprobetrace.txt
+++ b/Documentation/trace/kprobetrace.txt
@@ -25,14 +25,15 @@ probe events via /sys/kernel/debug/tracing/events/kprobes/<EVENT>/filter.
 
 Synopsis of kprobe_events
 -------------------------
-  p[:EVENT] SYMBOL[+offs|-offs]|MEMADDR [FETCHARGS]    : Set a probe
-  r[:EVENT] SYMBOL[+0] [FETCHARGS]                     : Set a return probe
+  p[:EVENT] SYMBOL[+offs]|MEMADDR [FETCHARGS]  : Set a probe
+  r[:EVENT] SYMBOL[+0] [FETCHARGS]             : Set a return probe
 
- EVENT                 : Event name.
- SYMBOL[+offs|-offs]   : Symbol+offset where the probe is inserted.
- MEMADDR               : Address where the probe is inserted.
+ EVENT         : Event name. If omitted, the event name is generated
+                 based on SYMBOL+offs or MEMADDR.
+ SYMBOL[+offs] : Symbol+offset where the probe is inserted.
+ MEMADDR       : Address where the probe is inserted.
 
- FETCHARGS             : Arguments.
+ FETCHARGS     : Arguments. Each probe can have up to 128 args.
   %REG : Fetch register REG
   sN   : Fetch Nth entry of stack (N >= 0)
   sa   : Fetch stack address.
@@ -69,6 +70,14 @@ filter:
  names and field names for describing filters.
 
 
+Event Profiling
+---------------
+ You can check the total number of probe hits and probe miss-hits via
+/sys/kernel/debug/tracing/kprobe_profile.
+ The first column is event name, the second is the number of probe hits,
+the third is the number of probe miss-hits.
+
+
 Usage examples
 --------------
 To add a probe as a new event, write a new definition to kprobe_events