From e162b39a368f0401e41b558f430c354d12a85b37 Mon Sep 17 00:00:00 2001 From: Mandeep Singh Baines Date: Thu, 15 Jan 2009 11:08:40 -0800 Subject: softlockup: decouple hung tasks check from softlockup detection Decoupling allows: * hung tasks check to happen at very low priority * hung tasks check and softlockup to be enabled/disabled independently at compile and/or run-time * individual panic settings to be enabled disabled independently at compile and/or run-time * softlockup threshold to be reduced without increasing hung tasks poll frequency (hung task check is expensive relative to softlock watchdog) * hung task check to be zero over-head when disabled at run-time Signed-off-by: Mandeep Singh Baines Signed-off-by: Ingo Molnar --- lib/Kconfig.debug | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) (limited to 'lib/Kconfig.debug') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 4c9ae6085c75..883ecea22f37 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -186,6 +186,44 @@ config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC default 1 if BOOTPARAM_SOFTLOCKUP_PANIC +config DETECT_HUNG_TASK + bool "Detect Hung Tasks" + depends on DEBUG_KERNEL + default y + help + Say Y here to enable the kernel to detect "hung tasks", + which are bugs that cause the task to be stuck in + uninterruptible "D" state indefinitiley. + + When a hung task is detected, the kernel will print the + current stack trace (which you should report), but the + task will stay in uninterruptible state. If lockdep is + enabled then all held locks will also be reported. This + feature has negligible overhead. + +config BOOTPARAM_HUNG_TASK_PANIC + bool "Panic (Reboot) On Hung Tasks" + depends on DETECT_HUNG_TASK + help + Say Y here to enable the kernel to panic on "hung tasks", + which are bugs that cause the kernel to leave a task stuck + in uninterruptible "D" state. + + The panic can be used in combination with panic_timeout, + to cause the system to reboot automatically after a + hung task has been detected. This feature is useful for + high-availability systems that have uptime guarantees and + where a hung tasks must be resolved ASAP. + + Say N if unsure. + +config BOOTPARAM_HUNG_TASK_PANIC_VALUE + int + depends on DETECT_HUNG_TASK + range 0 1 + default 0 if !BOOTPARAM_HUNG_TASK_PANIC + default 1 if BOOTPARAM_HUNG_TASK_PANIC + config SCHED_DEBUG bool "Collect scheduler debugging info" depends on DEBUG_KERNEL && PROC_FS -- cgit v1.2.3 From adf8b37bafc1495393201a2ae4235846371870d0 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Thu, 12 Feb 2009 13:56:34 +0100 Subject: [ARM] 5386/2: unwind: Add Makefile and Kconfig entries for ARM stack unwinding This patch also makes the frame pointer default to y only if !ARM_UNWIND. LOCKDEP no longer selects FRAME_POINTER if ARM_UNWIND is enabled. Signed-off-by: Catalin Marinas Signed-off-by: Russell King --- lib/Kconfig.debug | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/Kconfig.debug') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 29044f500269..08275a5aa00e 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -402,7 +402,7 @@ config LOCKDEP bool depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT select STACKTRACE - select FRAME_POINTER if !X86 && !MIPS && !PPC + select FRAME_POINTER if !X86 && !MIPS && !PPC && !ARM_UNWIND select KALLSYMS select KALLSYMS_ALL -- cgit v1.2.3 From 5ee00bd4691e7364bb7b62e2068d473cd5cb9320 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 9 Jan 2009 12:14:24 +0100 Subject: dma-debug: add Kconfig entry Impact: add a Kconfig entry for DMA-API debugging Signed-off-by: Joerg Roedel --- lib/Kconfig.debug | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'lib/Kconfig.debug') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 1bcf9cd4baa0..d9cbada7e2f8 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -902,6 +902,17 @@ config DYNAMIC_PRINTK_DEBUG debugging for all modules. This mode can be turned off via the above disable command. +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" -- cgit v1.2.3 From e9d376f0fa66bd630fe27403669c6ae6c22a868f Mon Sep 17 00:00:00 2001 From: Jason Baron Date: Thu, 5 Feb 2009 11:51:38 -0500 Subject: dynamic debug: combine dprintk and dynamic printk This patch combines Greg Bank's dprintk() work with the existing dynamic printk patchset, we are now calling it 'dynamic debug'. The new feature of this patchset is a richer /debugfs control file interface, (an example output from my system is at the bottom), which allows fined grained control over the the debug output. The output can be controlled by function, file, module, format string, and line number. for example, enabled all debug messages in module 'nf_conntrack': echo -n 'module nf_conntrack +p' > /mnt/debugfs/dynamic_debug/control to disable them: echo -n 'module nf_conntrack -p' > /mnt/debugfs/dynamic_debug/control A further explanation can be found in the documentation patch. Signed-off-by: Greg Banks Signed-off-by: Jason Baron Signed-off-by: Greg Kroah-Hartman --- lib/Kconfig.debug | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/Kconfig.debug') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 1bcf9cd4baa0..0dd1c04c7323 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -847,7 +847,7 @@ config BUILD_DOCSRC Say N if you are unsure. -config DYNAMIC_PRINTK_DEBUG +config DYNAMIC_DEBUG bool "Enable dynamic printk() call support" default n depends on PRINTK -- cgit v1.2.3 From 86151fdf38b3795f292b39defbff39d2684b9c8c Mon Sep 17 00:00:00 2001 From: Jason Baron Date: Thu, 5 Feb 2009 11:53:15 -0500 Subject: dynamic debug: update docs updates the documentation for 'dynamic debug' feature. Signed-off-by: Greg Banks Signed-off-by: Jason Baron Signed-off-by: Greg Kroah-Hartman --- lib/Kconfig.debug | 72 +++++++++++++++++++++++++++++++------------------------ 1 file changed, 41 insertions(+), 31 deletions(-) (limited to 'lib/Kconfig.debug') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 0dd1c04c7323..8fee0a13ac58 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -848,59 +848,69 @@ config BUILD_DOCSRC Say N if you are unsure. config DYNAMIC_DEBUG - bool "Enable dynamic printk() call support" + bool "Enable dynamic printk() support" default n depends on PRINTK + depends on DEBUG_FS select PRINTK_DEBUG help Compiles debug level messages into the kernel, which would not otherwise be available at runtime. These messages can then be - enabled/disabled on a per module basis. 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%. + 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%. Usage: - Dynamic debugging is controlled by the debugfs file, - dynamic_printk/modules. This file contains a list of the modules that - can be enabled. The format of the file is the module name, followed - by a set of flags that can be enabled. The first flag is always the - 'enabled' flag. For example: + Dynamic debugging is controlled via the 'dynamic_debug/ddebug' 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: /dynamic_debug/ddebug. 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 - : Name of the module in which the debug call resides - : whether the messages are enabled or not + 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: - snd_hda_intel enabled=0 - fixup enabled=0 - driver enabled=0 + nullarbor:~ # cat /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 " > dynamic_printk/modules + // enable the message at line 1603 of file svcsock.c + nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' > + /dynamic_debug/ddebug - Disable a module: + // enable all the messages in file svcsock.c + nullarbor:~ # echo -n 'file svcsock.c +p' > + /dynamic_debug/ddebug - $echo "set enabled=0 " > dynamic_printk/modules + // enable all the messages in the NFS server module + nullarbor:~ # echo -n 'module nfsd +p' > + /dynamic_debug/ddebug - Enable all modules: + // enable all 12 messages in the function svc_process() + nullarbor:~ # echo -n 'func svc_process +p' > + /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' > + /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. source "samples/Kconfig" -- cgit v1.2.3 From 6a11f75b6a17b5d9ac5025f8d048382fd1f47377 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Tue, 31 Mar 2009 15:23:17 -0700 Subject: generic debug pagealloc CONFIG_DEBUG_PAGEALLOC is now supported by x86, powerpc, sparc64, and s390. This patch implements it for the rest of the architectures by filling the pages with poison byte patterns after free_pages() and verifying the poison patterns before alloc_pages(). This generic one cannot detect invalid page accesses immediately but invalid read access may cause invalid dereference by poisoned memory and invalid write access can be detected after a long delay. Signed-off-by: Akinobu Mita Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 1 + 1 file changed, 1 insertion(+) (limited to 'lib/Kconfig.debug') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 58bfe7e8faba..9638d99644af 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -796,6 +796,7 @@ config SYSCTL_SYSCALL_CHECK to properly maintain and use. This enables checks that help you to keep things correct. +source mm/Kconfig.debug source kernel/trace/Kconfig config PROVIDE_OHCI1394_DMA_INIT -- cgit v1.2.3 From 77d05632baee21b1cef8730d7c06aa69601e4dca Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 7 Apr 2009 08:55:36 +0200 Subject: softlockup: make DETECT_HUNG_TASK default depend on DETECT_SOFTLOCKUP Don't offer a default-y option when the user has turned off CONFIG_DETECT_SOFTLOCKUP already. Do offer it as 'y' only if DETECT_SOFTLOCKUP is on already. This makes it match previous behavior - where the hung-task check was embedded i CONFIG_DETECT_SOFTLOCKUP code. Cc: Linus Torvalds Signed-off-by: Ingo Molnar --- lib/Kconfig.debug | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/Kconfig.debug') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 4934eaa21e1e..898e07c33c3c 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -189,7 +189,7 @@ config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE config DETECT_HUNG_TASK bool "Detect Hung Tasks" depends on DEBUG_KERNEL - default y + default DETECT_SOFTLOCKUP help Say Y here to enable the kernel to detect "hung tasks", which are bugs that cause the task to be stuck in -- cgit v1.2.3