summaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2009-03-26 19:17:04 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2009-03-26 19:17:04 +0100
commit0c93ea4064a209cdc36de8a9a3003d43d08f46f7 (patch)
treeff19952407c523a1349ef56c05993416dd28437e /Documentation
parentMerge git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6 (diff)
parentDynamic debug: fix pr_fmt() build error (diff)
downloadlinux-0c93ea4064a209cdc36de8a9a3003d43d08f46f7.tar.xz
linux-0c93ea4064a209cdc36de8a9a3003d43d08f46f7.zip
Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (61 commits) Dynamic debug: fix pr_fmt() build error Dynamic debug: allow simple quoting of words dynamic debug: update docs dynamic debug: combine dprintk and dynamic printk sysfs: fix some bin_vm_ops errors kobject: don't block for each kobject_uevent sysfs: only allow one scheduled removal callback per kobj Driver core: Fix device_move() vs. dpm list ordering, v2 Driver core: some cleanup on drivers/base/sys.c Driver core: implement uevent suppress in kobject vcs: hook sysfs devices into object lifetime instead of "binding" driver core: fix passing platform_data driver core: move platform_data into platform_device sysfs: don't block indefinitely for unmapped files. driver core: move knode_bus into private structure driver core: move knode_driver into private structure driver core: move klist_children into private structure driver core: create a private portion of struct device driver core: remove polling for driver_probe_done(v5) sysfs: reference sysfs_dirent from sysfs inodes ... Fixed conflicts in drivers/sh/maple/maple.c manually
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/DocBook/uio-howto.tmpl29
-rw-r--r--Documentation/dynamic-debug-howto.txt240
-rw-r--r--Documentation/kernel-parameters.txt5
3 files changed, 265 insertions, 9 deletions
diff --git a/Documentation/DocBook/uio-howto.tmpl b/Documentation/DocBook/uio-howto.tmpl
index 52e1b79ce0e6..8f6e3b2403c7 100644
--- a/Documentation/DocBook/uio-howto.tmpl
+++ b/Documentation/DocBook/uio-howto.tmpl
@@ -42,6 +42,13 @@ GPL version 2.
<revhistory>
<revision>
+ <revnumber>0.8</revnumber>
+ <date>2008-12-24</date>
+ <authorinitials>hjk</authorinitials>
+ <revremark>Added name attributes in mem and portio sysfs directories.
+ </revremark>
+ </revision>
+ <revision>
<revnumber>0.7</revnumber>
<date>2008-12-23</date>
<authorinitials>hjk</authorinitials>
@@ -303,12 +310,19 @@ interested in translating it, please email me
appear if the size of the mapping is not 0.
</para>
<para>
- Each <filename>mapX/</filename> directory contains two read-only files
- that show start address and size of the memory:
+ Each <filename>mapX/</filename> directory contains four read-only files
+ that show attributes of the memory:
</para>
<itemizedlist>
<listitem>
<para>
+ <filename>name</filename>: A string identifier for this mapping. This
+ is optional, the string can be empty. Drivers can set this to make it
+ easier for userspace to find the correct mapping.
+ </para>
+</listitem>
+<listitem>
+ <para>
<filename>addr</filename>: The address of memory that can be mapped.
</para>
</listitem>
@@ -366,12 +380,19 @@ offset = N * getpagesize();
<filename>/sys/class/uio/uioX/portio/</filename>.
</para>
<para>
- Each <filename>portX/</filename> directory contains three read-only
- files that show start, size, and type of the port region:
+ Each <filename>portX/</filename> directory contains four read-only
+ files that show name, start, size, and type of the port region:
</para>
<itemizedlist>
<listitem>
<para>
+ <filename>name</filename>: A string identifier for this port region.
+ The string is optional and can be empty. Drivers can set it to make it
+ easier for userspace to find a certain port region.
+ </para>
+</listitem>
+<listitem>
+ <para>
<filename>start</filename>: The first port of this region.
</para>
</listitem>
diff --git a/Documentation/dynamic-debug-howto.txt b/Documentation/dynamic-debug-howto.txt
new file mode 100644
index 000000000000..674c5663d346
--- /dev/null
+++ b/Documentation/dynamic-debug-howto.txt
@@ -0,0 +1,240 @@
+
+Introduction
+============
+
+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
+dynamically enabled per-callsite.
+
+Dynamic debug has even more useful features:
+
+ * Simple query language allows turning on and off debugging statements by
+ matching any combination of:
+
+ - source filename
+ - function name
+ - line number (including ranges of line numbers)
+ - module name
+ - format string
+
+ * 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_debug()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
+enable printing from source file 'svcsock.c', line 1603 you simply do:
+
+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:
+
+nullarbor:~ # echo 'file svcsock.c wtf 1 +p' >
+ <debugfs>/dynamic_debug/control
+-bash: echo: write error: Invalid argument
+
+Viewing Dynamic Debug Behaviour
+===========================
+
+You can view the currently configured behaviour of all the debug 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"
+...
+
+
+You can also apply standard Unix text manipulation filters to this
+data, e.g.
+
+nullarbor:~ # grep -i rdma <debugfs>/dynamic_debug/control | wc -l
+62
+
+nullarbor:~ # grep -i tcp <debugfs>/dynamic_debug/control | wc -l
+42
+
+Note in particular that the third column shows the enabled behaviour
+flags for each debug statement callsite (see below for definitions of the
+flags). The default value, no extra behaviour 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 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:
+
+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:
+
+nullarbor:~ # echo 'file svcsock.c line 1603 +p' > /proc/dprintk ;\
+> echo 'file svcsock.c line 1563 +p' > /proc/dprintk
+
+or even like:
+
+nullarbor:~ # (
+> echo 'file svcsock.c line 1603 +p' ;\
+> echo 'file svcsock.c line 1563 +p' ;\
+> ) > /proc/dprintk
+
+At the syntactical level, a command comprises a sequence of match
+specifications, followed by a flags change specification.
+
+command ::= match-spec* flags-spec
+
+The match-spec's are used to choose a subset of the known dprintk()
+callsites to which to apply the flags-spec. Think of them as a query
+with implicit ANDs between each pair. Note that an empty list of
+match-specs is possible, but is not very useful because it will not
+match any 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:
+
+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.
+
+lineno ::= unsigned-int
+
+The meanings of each keyword are:
+
+func
+ The given string is compared against the function name
+ of each callsite. Example:
+
+ func svc_tcp_accept
+
+file
+ The given string is compared against either the full
+ pathname or the basename of the source file of each
+ callsite. Examples:
+
+ file svcsock.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:
+
+ 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.
+ Alternatively, the string can be enclosed in double quote
+ characters (") or single quote characters (').
+ Examples:
+
+ format svcrdma: // many of the NFS/RDMA server dprintks
+ format readahead // some dprintks 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 dprintk() 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:
+
+ 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:
+
+-
+ remove the given flags
+
++
+ add the given flags
+
+=
+ set the flags to the given flags
+
+The flags are:
+
+p
+ Causes a printk() message to be emitted to dmesg
+
+Note the regexp ^[-+=][scp]+$ matches a flags specification.
+Note also that there is no convenient syntax to remove all
+the flags at once, you need to use "-psc".
+
+Examples
+========
+
+// 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' >
+ <debugfs>/dynamic_debug/control
+
+// 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' >
+ <debugfs>/dynamic_debug/control
+
+// 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' >
+ <debugfs>/dynamic_debug/control
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 224263e7711f..1a29ff3df3c5 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1826,11 +1826,6 @@ and is between 256 and 4096 characters. It is defined in the file
autoconfiguration.
Ranges are in pairs (memory base and size).
- dynamic_printk Enables pr_debug()/dev_dbg() calls if
- CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled.
- These can also be switched on/off via
- <debugfs>/dynamic_printk/modules
-
print-fatal-signals=
[KNL] debug: print fatal signals
print-fatal-signals=1: print segfault info to