tracing: Update documentation on tracepoint glob matching
b0f1a59a "tracing/filters: Use a different op for glob match" added
glob matching to tracepoint filter strings. It uses the ftrace function
tracing glob matching facility that allows for the wild card character (*)
to be used at the start and/or end of the matching string.
But the documentation still states that the filtering only allows for
exact string matches.
Cc: Li Zefan <lizefan@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/Documentation/trace/events.txt b/Documentation/trace/events.txt
index 4191124..37732a2 100644
--- a/Documentation/trace/events.txt
+++ b/Documentation/trace/events.txt
@@ -187,9 +187,18 @@
And for string fields they are:
-==, !=
+==, !=, ~
-Currently, only exact string matches are supported.
+The glob (~) only accepts a wild card character (*) at the start and or
+end of the string. For example:
+
+ prev_comm ~ "*sh"
+ prev_comm ~ "sh*"
+ prev_comm ~ "*sh*"
+
+But does not allow for it to be within the string:
+
+ prev_comm ~ "ba*sh" <-- is invalid
5.2 Setting filters
-------------------