Range: 0 - 8192
Default: 64
+ dma_debug=off If the kernel is compiled with DMA_API_DEBUG support
+ this option disables the debugging code at boot.
+
+ dma_debug_entries=<number>
+ This option allows to tune the number of preallocated
+ entries for DMA-API debugging code. One entry is
+ required per DMA-API allocation. Use this if the
+ DMA-API debugging code disables itself because the
+ architectural default is too low.
+
hpet= [X86-32,HPET] option to control HPET usage
- Format: { enable (default) | disable | force }
+ Format: { enable (default) | disable | force |
+ verbose }
disable: disable HPET and use PIT instead
force: allow force enabled of undocumented chips (ICH4,
VIA, nVidia)
From a live system:
- snd_hda_intel enabled=0
- fixup enabled=0
- driver enabled=0
+ nullarbor:~ # cat <debugfs>/dynamic_debug/ddebug
+ # 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"
- Enable a module:
+ Example usage:
- $echo "set enabled=1 <module_name>" > dynamic_printk/modules
+ // enable the message at line 1603 of file svcsock.c
+ nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
+ <debugfs>/dynamic_debug/ddebug
- Disable a module:
+ // enable all the messages in file svcsock.c
+ nullarbor:~ # echo -n 'file svcsock.c +p' >
+ <debugfs>/dynamic_debug/ddebug
- $echo "set enabled=0 <module_name>" > dynamic_printk/modules
+ // enable all the messages in the NFS server module
+ nullarbor:~ # echo -n 'module nfsd +p' >
+ <debugfs>/dynamic_debug/ddebug
- Enable all modules:
+ // enable all 12 messages in the function svc_process()
+ nullarbor:~ # echo -n 'func svc_process +p' >
+ <debugfs>/dynamic_debug/ddebug
- $echo "set enabled=1 all" > dynamic_printk/modules
+ // disable all 12 messages in the function svc_process()
+ nullarbor:~ # echo -n 'func svc_process -p' >
+ <debugfs>/dynamic_debug/ddebug
- Disable all modules:
-
- $echo "set enabled=0 all" > dynamic_printk/modules
-
- Finally, passing "dynamic_printk" at the command line enables
- debugging for all modules. This mode can be turned off via the above
- disable command.
+ See Documentation/dynamic-debug-howto.txt for additional information.
+config DMA_API_DEBUG
+ bool "Enable debugging of DMA-API usage"
+ depends on HAVE_DMA_API_DEBUG
+ help
+ Enable this option to debug the use of the DMA API by device drivers.
+ With this option you will be able to detect common bugs in device
+ drivers like double-freeing of DMA mappings or freeing mappings that
+ were never allocated.
+ This option causes a performance degredation. Use only if you want
+ to debug device drivers. If unsure, say N.
+
source "samples/Kconfig"
source "lib/Kconfig.kgdb"
obj-$(CONFIG_HAVE_ARCH_TRACEHOOK) += syscall.o
- obj-$(CONFIG_DYNAMIC_PRINTK_DEBUG) += dynamic_printk.o
+ obj-$(CONFIG_DYNAMIC_DEBUG) += dynamic_debug.o
+
+ obj-$(CONFIG_NLATTR) += nlattr.o
+obj-$(CONFIG_DMA_API_DEBUG) += dma-debug.o
+
hostprogs-y := gen_crc32table
clean-files := crc32table.h