Merge branches 'x86-asm-for-linus', 'x86-cleanups-for-linus', 'x86-cpu-for-linus...

[cascardo/linux.git] / lib / Kconfig.debug

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 6777153..a42d3ae 100644 (file)
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -3,12 +3,16 @@ config PRINTK_TIME
        bool "Show timing information on printks"
        depends on PRINTK
        help
-         Selecting this option causes timing information to be
-         included in printk output.  This allows you to measure
-         the interval between kernel operations, including bootup
-         operations.  This is useful for identifying long delays
-         in kernel startup.  Or add printk.time=1 at boot-time.
-         See Documentation/kernel-parameters.txt
+         Selecting this option causes time stamps of the printk()
+         messages to be added to the output of the syslog() system
+         call and at the console.
+
+         The timestamp is always recorded internally, and exported
+         to /dev/kmsg. This flag just specifies if the timestamp should
+         be included, not that the timestamp is recorded.
+
+         The behavior is also controlled by the kernel command line
+         parameter printk.time=1. See Documentation/kernel-parameters.txt
 
 config DEFAULT_MESSAGE_LOGLEVEL
        int "Default message log level (1-7)"
@@ -70,6 +74,15 @@ config STRIP_ASM_SYMS
          that look like '.Lxxx') so they don't pollute the output of
          get_wchan() and suchlike.
 
+config READABLE_ASM
+        bool "Generate readable assembler code"
+        depends on DEBUG_KERNEL
+        help
+          Disable some compiler optimizations that tend to generate human unreadable
+          assembler output. This may make the kernel slightly slower, but it helps
+          to keep kernel developers who have to stare a lot at assembler listings
+          sane.
+
 config UNUSED_SYMBOLS
        bool "Enable unused/obsolete exported symbols"
        default y if X86
@@ -1205,8 +1218,13 @@ config DYNAMIC_DEBUG
          otherwise be available at runtime. These messages can then be
          enabled/disabled based on various levels of scope - per source file,
          function, module, format string, and line number. This mechanism
-         implicitly enables all pr_debug() and dev_dbg() calls. The impact of
-         this compile option is a larger kernel text size of about 2%.
+         implicitly compiles in all pr_debug() and dev_dbg() calls, which
+         enlarges the kernel text size by about 2%.
+
+         If a source file is compiled with DEBUG flag set, any
+         pr_debug() calls in it are enabled by default, but can be
+         disabled at runtime as below.  Note that DEBUG flag is
+         turned on by many CONFIG_*DEBUG* options.
 
          Usage:
 
@@ -1223,16 +1241,16 @@ config DYNAMIC_DEBUG
          lineno : line number of the debug statement
          module : module that contains the debug statement
          function : function that contains the debug statement
-          flags : 'p' means the line is turned 'on' for printing
+          flags : '=p' means the line is turned 'on' for printing
           format : the format used for the debug statement
 
          From a live system:
 
                nullarbor:~ # cat <debugfs>/dynamic_debug/control
                # filename:lineno [module]function flags format
-               fs/aio.c:222 [aio]__put_ioctx - "__put_ioctx:\040freeing\040%p\012"
-               fs/aio.c:248 [aio]ioctx_alloc - "ENOMEM:\040nr_events\040too\040high\012"
-               fs/aio.c:1770 [aio]sys_io_cancel - "calling\040cancel\012"
+               fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
+               fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
+               fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
 
          Example usage: