dynamic-debug-howto.txt: update since new wildcard support
Add the usage of using new feature wildcard support.
Signed-off-by: Du, Changbin <changbin.du@gmail.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/dynamic-debug-howto.txt b/Documentation/dynamic-debug-howto.txt
index 1bbdcfc..46325eb 100644
--- a/Documentation/dynamic-debug-howto.txt
+++ b/Documentation/dynamic-debug-howto.txt
@@ -108,6 +108,12 @@
~# cat query-batch-file > <debugfs>/dynamic_debug/control
+A another way is to use wildcard. The match rule support '*' (matches
+zero or more characters) and '?' (matches exactly one character).For
+example, you can match all usb drivers:
+
+ ~# echo "file drivers/usb/* +p" > <debugfs>/dynamic_debug/control
+
At the syntactical level, a command comprises a sequence of match
specifications, followed by a flags change specification.
@@ -315,6 +321,9 @@
nullarbor:~ # echo -n 'format "nfsd: READ" +p' >
<debugfs>/dynamic_debug/control
+// enable messages in files of which the pathes include string "usb"
+nullarbor:~ # echo -n '*usb* +p' > <debugfs>/dynamic_debug/control
+
// enable all messages
nullarbor:~ # echo -n '+p' > <debugfs>/dynamic_debug/control