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Diffstat (limited to 'Documentation/dynamic-debug-howto.txt')
| -rw-r--r-- | Documentation/dynamic-debug-howto.txt | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/Documentation/dynamic-debug-howto.txt b/Documentation/dynamic-debug-howto.txt index 58ea64a96165..f959909d7154 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. Dynamic debug is designed to allow you to dynamically enable/disable kernel code to obtain additional kernel information. Currently, if -CONFIG_DYNAMIC_DEBUG is set, then all pr_debug()/dev_debug() calls can be +CONFIG_DYNAMIC_DEBUG is set, then all pr_debug()/dev_dbg() calls can be dynamically enabled per-callsite. Dynamic debug has even more useful features: @@ -26,7 +26,7 @@ Dynamic debug has even more useful features: Controlling dynamic debug Behaviour =================================== -The behaviour of pr_debug()/dev_debug()s are controlled via writing to a +The behaviour of pr_debug()/dev_dbg()s are controlled via writing to a control file in the 'debugfs' filesystem. Thus, you must first mount the debugfs filesystem, in order to make use of this feature. Subsequently, we refer to the control file as: <debugfs>/dynamic_debug/control. For example, if you want to @@ -205,12 +205,20 @@ of the characters: The flags are: +f + Include the function name in the printed message +l + Include line number in the printed message +m + Include module name in the printed message p Causes a printk() message to be emitted to dmesg +t + Include thread ID in messages not generated from interrupt context -Note the regexp ^[-+=][scp]+$ matches a flags specification. +Note the regexp ^[-+=][flmpt]+$ matches a flags specification. Note also that there is no convenient syntax to remove all -the flags at once, you need to use "-psc". +the flags at once, you need to use "-flmpt". Debug messages during boot process |
