Documentation/dynamic-debug-howto.txt: convert it to ReST markup
- use a quote blocks where needed; - fix the chapter/section/subsection markups; - use ``foo`` for monotonic; - use .. note:: for the line-range note; - cleanup whitespaces; - add it to the user's book. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This commit is contained in:
Mauro Carvalho Chehab
parent
d9f92f9f9d
commit
7d4e3517bd
|
|
@ -1,3 +1,6 @@
|
|||
Dynamic debug
|
||||
+++++++++++++
|
||||
|
||||
|
||||
Introduction
|
||||
============
|
||||
|
|
@ -6,16 +9,16 @@ This document describes how to use the dynamic debug (dyndbg) 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_dbg() and
|
||||
print_hex_dump_debug()/print_hex_dump_bytes() calls can be dynamically
|
||||
``CONFIG_DYNAMIC_DEBUG`` is set, then all ``pr_debug()``/``dev_dbg()`` and
|
||||
``print_hex_dump_debug()``/``print_hex_dump_bytes()`` calls can be dynamically
|
||||
enabled per-callsite.
|
||||
|
||||
If CONFIG_DYNAMIC_DEBUG is not set, print_hex_dump_debug() is just
|
||||
shortcut for print_hex_dump(KERN_DEBUG).
|
||||
If ``CONFIG_DYNAMIC_DEBUG`` is not set, ``print_hex_dump_debug()`` is just
|
||||
shortcut for ``print_hex_dump(KERN_DEBUG)``.
|
||||
|
||||
For print_hex_dump_debug()/print_hex_dump_bytes(), format string is
|
||||
its 'prefix_str' argument, if it is constant string; or "hexdump"
|
||||
in case 'prefix_str' is build dynamically.
|
||||
For ``print_hex_dump_debug()``/``print_hex_dump_bytes()``, format string is
|
||||
its ``prefix_str`` argument, if it is constant string; or ``hexdump``
|
||||
in case ``prefix_str`` is build dynamically.
|
||||
|
||||
Dynamic debug has even more useful features:
|
||||
|
||||
|
|
@ -28,96 +31,95 @@ Dynamic debug has even more useful features:
|
|||
- module name
|
||||
- format string
|
||||
|
||||
* Provides a debugfs control file: <debugfs>/dynamic_debug/control
|
||||
* Provides a debugfs control file: ``<debugfs>/dynamic_debug/control``
|
||||
which can be read to display the complete list of known debug
|
||||
statements, to help guide you
|
||||
|
||||
Controlling dynamic debug Behaviour
|
||||
===================================
|
||||
|
||||
The behaviour of pr_debug()/dev_dbg()s are controlled via writing to a
|
||||
The behaviour of ``pr_debug()``/``dev_dbg()`` 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 enable
|
||||
printing from source file 'svcsock.c', line 1603 you simply do:
|
||||
``<debugfs>/dynamic_debug/control``. For example, if you want to enable
|
||||
printing from source file ``svcsock.c``, line 1603 you simply do::
|
||||
|
||||
nullarbor:~ # echo 'file svcsock.c line 1603 +p' >
|
||||
nullarbor:~ # echo 'file svcsock.c line 1603 +p' >
|
||||
<debugfs>/dynamic_debug/control
|
||||
|
||||
If you make a mistake with the syntax, the write will fail thus:
|
||||
If you make a mistake with the syntax, the write will fail thus::
|
||||
|
||||
nullarbor:~ # echo 'file svcsock.c wtf 1 +p' >
|
||||
nullarbor:~ # echo 'file svcsock.c wtf 1 +p' >
|
||||
<debugfs>/dynamic_debug/control
|
||||
-bash: echo: write error: Invalid argument
|
||||
-bash: echo: write error: Invalid argument
|
||||
|
||||
Viewing Dynamic Debug Behaviour
|
||||
===========================
|
||||
===============================
|
||||
|
||||
You can view the currently configured behaviour of all the debug
|
||||
statements via:
|
||||
statements via::
|
||||
|
||||
nullarbor:~ # cat <debugfs>/dynamic_debug/control
|
||||
# filename:lineno [module]function flags format
|
||||
/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svc_rdma.c:323 [svcxprt_rdma]svc_rdma_cleanup =_ "SVCRDMA Module Removed, deregister RPC RDMA transport\012"
|
||||
/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svc_rdma.c:341 [svcxprt_rdma]svc_rdma_init =_ "\011max_inline : %d\012"
|
||||
/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svc_rdma.c:340 [svcxprt_rdma]svc_rdma_init =_ "\011sq_depth : %d\012"
|
||||
/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svc_rdma.c:338 [svcxprt_rdma]svc_rdma_init =_ "\011max_requests : %d\012"
|
||||
...
|
||||
nullarbor:~ # cat <debugfs>/dynamic_debug/control
|
||||
# filename:lineno [module]function flags format
|
||||
/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svc_rdma.c:323 [svcxprt_rdma]svc_rdma_cleanup =_ "SVCRDMA Module Removed, deregister RPC RDMA transport\012"
|
||||
/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svc_rdma.c:341 [svcxprt_rdma]svc_rdma_init =_ "\011max_inline : %d\012"
|
||||
/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svc_rdma.c:340 [svcxprt_rdma]svc_rdma_init =_ "\011sq_depth : %d\012"
|
||||
/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svc_rdma.c:338 [svcxprt_rdma]svc_rdma_init =_ "\011max_requests : %d\012"
|
||||
...
|
||||
|
||||
|
||||
You can also apply standard Unix text manipulation filters to this
|
||||
data, e.g.
|
||||
data, e.g.::
|
||||
|
||||
nullarbor:~ # grep -i rdma <debugfs>/dynamic_debug/control | wc -l
|
||||
62
|
||||
nullarbor:~ # grep -i rdma <debugfs>/dynamic_debug/control | wc -l
|
||||
62
|
||||
|
||||
nullarbor:~ # grep -i tcp <debugfs>/dynamic_debug/control | wc -l
|
||||
42
|
||||
nullarbor:~ # grep -i tcp <debugfs>/dynamic_debug/control | wc -l
|
||||
42
|
||||
|
||||
The third column shows the currently enabled flags for each debug
|
||||
statement callsite (see below for definitions of the flags). The
|
||||
default value, with no flags enabled, is "=_". So you can view all
|
||||
the debug statement callsites with any non-default flags:
|
||||
|
||||
nullarbor:~ # awk '$3 != "=_"' <debugfs>/dynamic_debug/control
|
||||
# filename:lineno [module]function flags format
|
||||
/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svcsock.c:1603 [sunrpc]svc_send p "svc_process: st_sendto returned %d\012"
|
||||
default value, with no flags enabled, is ``=_``. So you can view all
|
||||
the debug statement callsites with any non-default flags::
|
||||
|
||||
nullarbor:~ # awk '$3 != "=_"' <debugfs>/dynamic_debug/control
|
||||
# filename:lineno [module]function flags format
|
||||
/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svcsock.c:1603 [sunrpc]svc_send p "svc_process: st_sendto returned %d\012"
|
||||
|
||||
Command Language Reference
|
||||
==========================
|
||||
|
||||
At the lexical level, a command comprises a sequence of words separated
|
||||
by spaces or tabs. So these are all equivalent:
|
||||
by spaces or tabs. So these are all equivalent::
|
||||
|
||||
nullarbor:~ # echo -c 'file svcsock.c line 1603 +p' >
|
||||
nullarbor:~ # echo -c 'file svcsock.c line 1603 +p' >
|
||||
<debugfs>/dynamic_debug/control
|
||||
nullarbor:~ # echo -c ' file svcsock.c line 1603 +p ' >
|
||||
nullarbor:~ # echo -c ' file svcsock.c line 1603 +p ' >
|
||||
<debugfs>/dynamic_debug/control
|
||||
nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
|
||||
nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
|
||||
<debugfs>/dynamic_debug/control
|
||||
|
||||
Command submissions are bounded by a write() system call.
|
||||
Multiple commands can be written together, separated by ';' or '\n'.
|
||||
Multiple commands can be written together, separated by ``;`` or ``\n``::
|
||||
|
||||
~# echo "func pnpacpi_get_resources +p; func pnp_assign_mem +p" \
|
||||
> <debugfs>/dynamic_debug/control
|
||||
|
||||
If your query set is big, you can batch them too:
|
||||
If your query set is big, you can batch them too::
|
||||
|
||||
~# 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:
|
||||
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.
|
||||
specifications, followed by a flags change specification::
|
||||
|
||||
command ::= match-spec* flags-spec
|
||||
command ::= match-spec* flags-spec
|
||||
|
||||
The match-spec's are used to choose a subset of the known pr_debug()
|
||||
callsites to which to apply the flags-spec. Think of them as a query
|
||||
|
|
@ -126,88 +128,92 @@ match-specs will select all debug statement callsites.
|
|||
|
||||
A match specification comprises a keyword, which controls the
|
||||
attribute of the callsite to be compared, and a value to compare
|
||||
against. Possible keywords are:
|
||||
against. Possible keywords are:::
|
||||
|
||||
match-spec ::= 'func' string |
|
||||
'file' string |
|
||||
'module' string |
|
||||
'format' string |
|
||||
'line' line-range
|
||||
match-spec ::= 'func' string |
|
||||
'file' string |
|
||||
'module' string |
|
||||
'format' string |
|
||||
'line' line-range
|
||||
|
||||
line-range ::= lineno |
|
||||
'-'lineno |
|
||||
lineno'-' |
|
||||
lineno'-'lineno
|
||||
// Note: line-range cannot contain space, e.g.
|
||||
// "1-30" is valid range but "1 - 30" is not.
|
||||
line-range ::= lineno |
|
||||
'-'lineno |
|
||||
lineno'-' |
|
||||
lineno'-'lineno
|
||||
|
||||
lineno ::= unsigned-int
|
||||
|
||||
.. note::
|
||||
|
||||
``line-range`` cannot contain space, e.g.
|
||||
"1-30" is valid range but "1 - 30" is not.
|
||||
|
||||
lineno ::= unsigned-int
|
||||
|
||||
The meanings of each keyword are:
|
||||
|
||||
func
|
||||
The given string is compared against the function name
|
||||
of each callsite. Example:
|
||||
of each callsite. Example::
|
||||
|
||||
func svc_tcp_accept
|
||||
func svc_tcp_accept
|
||||
|
||||
file
|
||||
The given string is compared against either the full pathname, the
|
||||
src-root relative pathname, or the basename of the source file of
|
||||
each callsite. Examples:
|
||||
each callsite. Examples::
|
||||
|
||||
file svcsock.c
|
||||
file kernel/freezer.c
|
||||
file /usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svcsock.c
|
||||
file svcsock.c
|
||||
file kernel/freezer.c
|
||||
file /usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svcsock.c
|
||||
|
||||
module
|
||||
The given string is compared against the module name
|
||||
of each callsite. The module name is the string as
|
||||
seen in "lsmod", i.e. without the directory or the .ko
|
||||
suffix and with '-' changed to '_'. Examples:
|
||||
seen in ``lsmod``, i.e. without the directory or the ``.ko``
|
||||
suffix and with ``-`` changed to ``_``. Examples::
|
||||
|
||||
module sunrpc
|
||||
module nfsd
|
||||
module sunrpc
|
||||
module nfsd
|
||||
|
||||
format
|
||||
The given string is searched for in the dynamic debug format
|
||||
string. Note that the string does not need to match the
|
||||
entire format, only some part. Whitespace and other
|
||||
special characters can be escaped using C octal character
|
||||
escape \ooo notation, e.g. the space character is \040.
|
||||
escape ``\ooo`` notation, e.g. the space character is ``\040``.
|
||||
Alternatively, the string can be enclosed in double quote
|
||||
characters (") or single quote characters (').
|
||||
Examples:
|
||||
characters (``"``) or single quote characters (``'``).
|
||||
Examples::
|
||||
|
||||
format svcrdma: // many of the NFS/RDMA server pr_debugs
|
||||
format readahead // some pr_debugs in the readahead cache
|
||||
format nfsd:\040SETATTR // one way to match a format with whitespace
|
||||
format "nfsd: SETATTR" // a neater way to match a format with whitespace
|
||||
format 'nfsd: SETATTR' // yet another way to match a format with whitespace
|
||||
format svcrdma: // many of the NFS/RDMA server pr_debugs
|
||||
format readahead // some pr_debugs in the readahead cache
|
||||
format nfsd:\040SETATTR // one way to match a format with whitespace
|
||||
format "nfsd: SETATTR" // a neater way to match a format with whitespace
|
||||
format 'nfsd: SETATTR' // yet another way to match a format with whitespace
|
||||
|
||||
line
|
||||
The given line number or range of line numbers is compared
|
||||
against the line number of each pr_debug() callsite. A single
|
||||
against the line number of each ``pr_debug()`` callsite. A single
|
||||
line number matches the callsite line number exactly. A
|
||||
range of line numbers matches any callsite between the first
|
||||
and last line number inclusive. An empty first number means
|
||||
the first line in the file, an empty line number means the
|
||||
last number in the file. Examples:
|
||||
last number in the file. Examples::
|
||||
|
||||
line 1603 // exactly line 1603
|
||||
line 1600-1605 // the six lines from line 1600 to line 1605
|
||||
line -1605 // the 1605 lines from line 1 to line 1605
|
||||
line 1600- // all lines from line 1600 to the end of the file
|
||||
line 1603 // exactly line 1603
|
||||
line 1600-1605 // the six lines from line 1600 to line 1605
|
||||
line -1605 // the 1605 lines from line 1 to line 1605
|
||||
line 1600- // all lines from line 1600 to the end of the file
|
||||
|
||||
The flags specification comprises a change operation followed
|
||||
by one or more flag characters. The change operation is one
|
||||
of the characters:
|
||||
of the characters::
|
||||
|
||||
- remove the given flags
|
||||
+ add the given flags
|
||||
= set the flags to the given flags
|
||||
|
||||
The flags are:
|
||||
The flags are::
|
||||
|
||||
p enables the pr_debug() callsite.
|
||||
f Include the function name in the printed message
|
||||
|
|
@ -216,14 +222,14 @@ The flags are:
|
|||
t Include thread ID in messages not generated from interrupt context
|
||||
_ No flags are set. (Or'd with others on input)
|
||||
|
||||
For print_hex_dump_debug() and print_hex_dump_bytes(), only 'p' flag
|
||||
For ``print_hex_dump_debug()`` and ``print_hex_dump_bytes()``, only ``p`` flag
|
||||
have meaning, other flags ignored.
|
||||
|
||||
For display, the flags are preceded by '='
|
||||
For display, the flags are preceded by ``=``
|
||||
(mnemonic: what the flags are currently equal to).
|
||||
|
||||
Note the regexp ^[-+=][flmpt_]+$ matches a flags specification.
|
||||
To clear all flags at once, use "=_" or "-flmpt".
|
||||
Note the regexp ``^[-+=][flmpt_]+$`` matches a flags specification.
|
||||
To clear all flags at once, use ``=_`` or ``-flmpt``.
|
||||
|
||||
|
||||
Debug messages during Boot Process
|
||||
|
|
@ -231,110 +237,117 @@ Debug messages during Boot Process
|
|||
|
||||
To activate debug messages for core code and built-in modules during
|
||||
the boot process, even before userspace and debugfs exists, use
|
||||
dyndbg="QUERY", module.dyndbg="QUERY", or ddebug_query="QUERY"
|
||||
(ddebug_query is obsoleted by dyndbg, and deprecated). QUERY follows
|
||||
``dyndbg="QUERY"``, ``module.dyndbg="QUERY"``, or ``ddebug_query="QUERY"``
|
||||
(``ddebug_query`` is obsoleted by ``dyndbg``, and deprecated). QUERY follows
|
||||
the syntax described above, but must not exceed 1023 characters. Your
|
||||
bootloader may impose lower limits.
|
||||
|
||||
These dyndbg params are processed just after the ddebug tables are
|
||||
These ``dyndbg`` params are processed just after the ddebug tables are
|
||||
processed, as part of the arch_initcall. Thus you can enable debug
|
||||
messages in all code run after this arch_initcall via this boot
|
||||
parameter.
|
||||
|
||||
On an x86 system for example ACPI enablement is a subsys_initcall and
|
||||
On an x86 system for example ACPI enablement is a subsys_initcall and::
|
||||
|
||||
dyndbg="file ec.c +p"
|
||||
|
||||
will show early Embedded Controller transactions during ACPI setup if
|
||||
your machine (typically a laptop) has an Embedded Controller.
|
||||
PCI (or other devices) initialization also is a hot candidate for using
|
||||
this boot parameter for debugging purposes.
|
||||
|
||||
If foo module is not built-in, foo.dyndbg will still be processed at
|
||||
If ``foo`` module is not built-in, ``foo.dyndbg`` will still be processed at
|
||||
boot time, without effect, but will be reprocessed when module is
|
||||
loaded later. dyndbg_query= and bare dyndbg= are only processed at
|
||||
loaded later. ``dyndbg_query=`` and bare ``dyndbg=`` are only processed at
|
||||
boot.
|
||||
|
||||
|
||||
Debug Messages at Module Initialization Time
|
||||
============================================
|
||||
|
||||
When "modprobe foo" is called, modprobe scans /proc/cmdline for
|
||||
foo.params, strips "foo.", and passes them to the kernel along with
|
||||
params given in modprobe args or /etc/modprob.d/*.conf files,
|
||||
When ``modprobe foo`` is called, modprobe scans ``/proc/cmdline`` for
|
||||
``foo.params``, strips ``foo.``, and passes them to the kernel along with
|
||||
params given in modprobe args or ``/etc/modprob.d/*.conf`` files,
|
||||
in the following order:
|
||||
|
||||
1. # parameters given via /etc/modprobe.d/*.conf
|
||||
options foo dyndbg=+pt
|
||||
options foo dyndbg # defaults to +p
|
||||
1. parameters given via ``/etc/modprobe.d/*.conf``::
|
||||
|
||||
2. # foo.dyndbg as given in boot args, "foo." is stripped and passed
|
||||
foo.dyndbg=" func bar +p; func buz +mp"
|
||||
options foo dyndbg=+pt
|
||||
options foo dyndbg # defaults to +p
|
||||
|
||||
3. # args to modprobe
|
||||
modprobe foo dyndbg==pmf # override previous settings
|
||||
2. ``foo.dyndbg`` as given in boot args, ``foo.`` is stripped and passed::
|
||||
|
||||
These dyndbg queries are applied in order, with last having final say.
|
||||
This allows boot args to override or modify those from /etc/modprobe.d
|
||||
foo.dyndbg=" func bar +p; func buz +mp"
|
||||
|
||||
3. args to modprobe::
|
||||
|
||||
modprobe foo dyndbg==pmf # override previous settings
|
||||
|
||||
These ``dyndbg`` queries are applied in order, with last having final say.
|
||||
This allows boot args to override or modify those from ``/etc/modprobe.d``
|
||||
(sensible, since 1 is system wide, 2 is kernel or boot specific), and
|
||||
modprobe args to override both.
|
||||
|
||||
In the foo.dyndbg="QUERY" form, the query must exclude "module foo".
|
||||
"foo" is extracted from the param-name, and applied to each query in
|
||||
"QUERY", and only 1 match-spec of each type is allowed.
|
||||
In the ``foo.dyndbg="QUERY"`` form, the query must exclude ``module foo``.
|
||||
``foo`` is extracted from the param-name, and applied to each query in
|
||||
``QUERY``, and only 1 match-spec of each type is allowed.
|
||||
|
||||
The dyndbg option is a "fake" module parameter, which means:
|
||||
The ``dyndbg`` option is a "fake" module parameter, which means:
|
||||
|
||||
- modules do not need to define it explicitly
|
||||
- every module gets it tacitly, whether they use pr_debug or not
|
||||
- it doesn't appear in /sys/module/$module/parameters/
|
||||
To see it, grep the control file, or inspect /proc/cmdline.
|
||||
- it doesn't appear in ``/sys/module/$module/parameters/``
|
||||
To see it, grep the control file, or inspect ``/proc/cmdline.``
|
||||
|
||||
For CONFIG_DYNAMIC_DEBUG kernels, any settings given at boot-time (or
|
||||
enabled by -DDEBUG flag during compilation) can be disabled later via
|
||||
the sysfs interface if the debug messages are no longer needed:
|
||||
For ``CONFIG_DYNAMIC_DEBUG`` kernels, any settings given at boot-time (or
|
||||
enabled by ``-DDEBUG`` flag during compilation) can be disabled later via
|
||||
the sysfs interface if the debug messages are no longer needed::
|
||||
|
||||
echo "module module_name -p" > <debugfs>/dynamic_debug/control
|
||||
|
||||
Examples
|
||||
========
|
||||
|
||||
// enable the message at line 1603 of file svcsock.c
|
||||
nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
|
||||
::
|
||||
|
||||
// enable the message at line 1603 of file svcsock.c
|
||||
nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
|
||||
<debugfs>/dynamic_debug/control
|
||||
|
||||
// enable all the messages in file svcsock.c
|
||||
nullarbor:~ # echo -n 'file svcsock.c +p' >
|
||||
// enable all the messages in file svcsock.c
|
||||
nullarbor:~ # echo -n 'file svcsock.c +p' >
|
||||
<debugfs>/dynamic_debug/control
|
||||
|
||||
// enable all the messages in the NFS server module
|
||||
nullarbor:~ # echo -n 'module nfsd +p' >
|
||||
// enable all the messages in the NFS server module
|
||||
nullarbor:~ # echo -n 'module nfsd +p' >
|
||||
<debugfs>/dynamic_debug/control
|
||||
|
||||
// enable all 12 messages in the function svc_process()
|
||||
nullarbor:~ # echo -n 'func svc_process +p' >
|
||||
// enable all 12 messages in the function svc_process()
|
||||
nullarbor:~ # echo -n 'func svc_process +p' >
|
||||
<debugfs>/dynamic_debug/control
|
||||
|
||||
// disable all 12 messages in the function svc_process()
|
||||
nullarbor:~ # echo -n 'func svc_process -p' >
|
||||
// disable all 12 messages in the function svc_process()
|
||||
nullarbor:~ # echo -n 'func svc_process -p' >
|
||||
<debugfs>/dynamic_debug/control
|
||||
|
||||
// enable messages for NFS calls READ, READLINK, READDIR and READDIR+.
|
||||
nullarbor:~ # echo -n 'format "nfsd: READ" +p' >
|
||||
// enable messages for NFS calls READ, READLINK, READDIR and READDIR+.
|
||||
nullarbor:~ # echo -n 'format "nfsd: READ" +p' >
|
||||
<debugfs>/dynamic_debug/control
|
||||
|
||||
// enable messages in files of which the paths include string "usb"
|
||||
nullarbor:~ # echo -n '*usb* +p' > <debugfs>/dynamic_debug/control
|
||||
// enable messages in files of which the paths include string "usb"
|
||||
nullarbor:~ # echo -n '*usb* +p' > <debugfs>/dynamic_debug/control
|
||||
|
||||
// enable all messages
|
||||
nullarbor:~ # echo -n '+p' > <debugfs>/dynamic_debug/control
|
||||
// enable all messages
|
||||
nullarbor:~ # echo -n '+p' > <debugfs>/dynamic_debug/control
|
||||
|
||||
// add module, function to all enabled messages
|
||||
nullarbor:~ # echo -n '+mf' > <debugfs>/dynamic_debug/control
|
||||
// add module, function to all enabled messages
|
||||
nullarbor:~ # echo -n '+mf' > <debugfs>/dynamic_debug/control
|
||||
|
||||
// boot-args example, with newlines and comments for readability
|
||||
Kernel command line: ...
|
||||
// see whats going on in dyndbg=value processing
|
||||
dynamic_debug.verbose=1
|
||||
// enable pr_debugs in 2 builtins, #cmt is stripped
|
||||
dyndbg="module params +p #cmt ; module sys +p"
|
||||
// enable pr_debugs in 2 functions in a module loaded later
|
||||
pc87360.dyndbg="func pc87360_init_device +p; func pc87360_find +p"
|
||||
// boot-args example, with newlines and comments for readability
|
||||
Kernel command line: ...
|
||||
// see whats going on in dyndbg=value processing
|
||||
dynamic_debug.verbose=1
|
||||
// enable pr_debugs in 2 builtins, #cmt is stripped
|
||||
dyndbg="module params +p #cmt ; module sys +p"
|
||||
// enable pr_debugs in 2 functions in a module loaded later
|
||||
pc87360.dyndbg="func pc87360_init_device +p; func pc87360_find +p"
|
||||
|
|
|
|||
Loading…
Reference in New Issue