diff options
| -rw-r--r-- | lib/Kconfig.debug | 177 |
1 files changed, 90 insertions, 87 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c0d41df..a6c2c5c 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1,3 +1,4 @@ +menu "printk and dmesg options" config PRINTK_TIME bool "Show timing information on printks" @@ -25,6 +26,95 @@ config DEFAULT_MESSAGE_LOGLEVEL that are auditing their logs closely may want to set it to a lower priority. +config BOOT_PRINTK_DELAY + bool "Delay each boot printk message by N milliseconds" + depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY + help + This build option allows you to read kernel boot messages + by inserting a short delay after each one. The delay is + specified in milliseconds on the kernel command line, + using "boot_delay=N". + + It is likely that you would also need to use "lpj=M" to preset + the "loops per jiffie" value. + See a previous boot log for the "lpj" value to use for your + system, and then set "lpj=M" before setting "boot_delay=N". + NOTE: Using this option may adversely affect SMP systems. + I.e., processors other than the first one may not boot up. + BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect + what it believes to be lockup conditions. + +config DYNAMIC_DEBUG + bool "Enable dynamic printk() support" + default n + depends on PRINTK + depends on DEBUG_FS + help + + Compiles debug level messages into the kernel, which would not + 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 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: + + Dynamic debugging is controlled via the 'dynamic_debug/control' file, + which is contained in the 'debugfs' filesystem. Thus, the debugfs + filesystem must first be mounted before making use of this feature. + We refer the control file as: <debugfs>/dynamic_debug/control. This + file contains a list of the debug statements that can be enabled. The + format for each line of the file is: + + filename:lineno [module]function flags format + + filename : source file of the debug statement + 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 + 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" + + Example usage: + + // 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 + + See Documentation/dynamic-debug-howto.txt for additional information. + +endmenu # "printk and dmesg options" + menu "Compile-time checks and compiler options" config DEBUG_INFO @@ -940,24 +1030,6 @@ config DEBUG_CREDENTIALS If unsure, say N. -config BOOT_PRINTK_DELAY - bool "Delay each boot printk message by N milliseconds" - depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY - help - This build option allows you to read kernel boot messages - by inserting a short delay after each one. The delay is - specified in milliseconds on the kernel command line, - using "boot_delay=N". - - It is likely that you would also need to use "lpj=M" to preset - the "loops per jiffie" value. - See a previous boot log for the "lpj" value to use for your - system, and then set "lpj=M" before setting "boot_delay=N". - NOTE: Using this option may adversely affect SMP systems. - I.e., processors other than the first one may not boot up. - BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect - what it believes to be lockup conditions. - menu "RCU Debugging" config PROVE_RCU @@ -1441,75 +1513,6 @@ config BUILD_DOCSRC Say N if you are unsure. -config DYNAMIC_DEBUG - bool "Enable dynamic printk() support" - default n - depends on PRINTK - depends on DEBUG_FS - help - - Compiles debug level messages into the kernel, which would not - 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 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: - - Dynamic debugging is controlled via the 'dynamic_debug/control' file, - which is contained in the 'debugfs' filesystem. Thus, the debugfs - filesystem must first be mounted before making use of this feature. - We refer the control file as: <debugfs>/dynamic_debug/control. This - file contains a list of the debug statements that can be enabled. The - format for each line of the file is: - - filename:lineno [module]function flags format - - filename : source file of the debug statement - 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 - 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" - - Example usage: - - // 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 - - See Documentation/dynamic-debug-howto.txt for additional information. - config DMA_API_DEBUG bool "Enable debugging of DMA-API usage" depends on HAVE_DMA_API_DEBUG |