Dynamic debug has even more useful features:
* Simple query language allows turning on and off debugging statements by
- matching any combination of:
+ matching any combination of 0 or 1 of:
- source filename
- function name
==========================
At the lexical level, a command comprises a sequence of words separated
-by whitespace characters. Note that newlines are treated as word
-separators and do *not* end a command or allow multiple commands to
-be done together. So these are all equivalent:
+by spaces or tabs. So these are all equivalent:
nullarbor:~ # echo -c 'file svcsock.c line 1603 +p' >
<debugfs>/dynamic_debug/control
nullarbor:~ # echo -c ' file svcsock.c line 1603 +p ' >
<debugfs>/dynamic_debug/control
-nullarbor:~ # echo -c 'file svcsock.c\nline 1603 +p' >
- <debugfs>/dynamic_debug/control
nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
<debugfs>/dynamic_debug/control
-Commands are bounded by a write() system call. If you want to do
-multiple commands you need to do a separate "echo" for each, like:
+Command submissions are bounded by a write() system call.
+Multiple commands can be written together, separated by ';' or '\n'.
-nullarbor:~ # echo 'file svcsock.c line 1603 +p' > /proc/dprintk ;\
-> echo 'file svcsock.c line 1563 +p' > /proc/dprintk
+ ~# echo "func pnpacpi_get_resources +p; func pnp_assign_mem +p" \
+ > <debugfs>/dynamic_debug/control
-or even like:
+If your query set is big, you can batch them too:
-nullarbor:~ # (
-> echo 'file svcsock.c line 1603 +p' ;\
-> echo 'file svcsock.c line 1563 +p' ;\
-> ) > /proc/dprintk
+ ~# cat query-batch-file > <debugfs>/dynamic_debug/control
At the syntactical level, a command comprises a sequence of match
specifications, followed by a flags change specification.