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-rw-r--r--Documentation/dynamic-debug-howto.txt16
1 files changed, 12 insertions, 4 deletions
diff --git a/Documentation/dynamic-debug-howto.txt b/Documentation/dynamic-debug-howto.txt
index 58ea64a9616..f959909d715 100644
--- a/Documentation/dynamic-debug-howto.txt
+++ b/Documentation/dynamic-debug-howto.txt
@@ -6,7 +6,7 @@ This document describes how to use the dynamic debug (ddebug) feature.
6 6
7Dynamic debug is designed to allow you to dynamically enable/disable kernel 7Dynamic debug is designed to allow you to dynamically enable/disable kernel
8code to obtain additional kernel information. Currently, if 8code to obtain additional kernel information. Currently, if
9CONFIG_DYNAMIC_DEBUG is set, then all pr_debug()/dev_debug() calls can be 9CONFIG_DYNAMIC_DEBUG is set, then all pr_debug()/dev_dbg() calls can be
10dynamically enabled per-callsite. 10dynamically enabled per-callsite.
11 11
12Dynamic debug has even more useful features: 12Dynamic debug has even more useful features:
@@ -26,7 +26,7 @@ Dynamic debug has even more useful features:
26Controlling dynamic debug Behaviour 26Controlling dynamic debug Behaviour
27=================================== 27===================================
28 28
29The behaviour of pr_debug()/dev_debug()s are controlled via writing to a 29The behaviour of pr_debug()/dev_dbg()s are controlled via writing to a
30control file in the 'debugfs' filesystem. Thus, you must first mount the debugfs 30control file in the 'debugfs' filesystem. Thus, you must first mount the debugfs
31filesystem, in order to make use of this feature. Subsequently, we refer to the 31filesystem, in order to make use of this feature. Subsequently, we refer to the
32control file as: <debugfs>/dynamic_debug/control. For example, if you want to 32control file as: <debugfs>/dynamic_debug/control. For example, if you want to
@@ -205,12 +205,20 @@ of the characters:
205 205
206The flags are: 206The flags are:
207 207
208f
209 Include the function name in the printed message
210l
211 Include line number in the printed message
212m
213 Include module name in the printed message
208p 214p
209 Causes a printk() message to be emitted to dmesg 215 Causes a printk() message to be emitted to dmesg
216t
217 Include thread ID in messages not generated from interrupt context
210 218
211Note the regexp ^[-+=][scp]+$ matches a flags specification. 219Note the regexp ^[-+=][flmpt]+$ matches a flags specification.
212Note also that there is no convenient syntax to remove all 220Note also that there is no convenient syntax to remove all
213the flags at once, you need to use "-psc". 221the flags at once, you need to use "-flmpt".
214 222
215 223
216Debug messages during boot process 224Debug messages during boot process