From 6e766410c4babd37bc7cd5e25009c179781742c8 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Mon, 12 May 2008 21:20:41 +0200 Subject: ftrace: annotate core code that should not be traced Mark with "notrace" functions in core code that should not be traced. The "notrace" attribute will prevent gcc from adding a call to ftrace on the annotated funtions. Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- lib/smp_processor_id.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c index 6c90fb90e19..e555ab62fba 100644 --- a/lib/smp_processor_id.c +++ b/lib/smp_processor_id.c @@ -7,7 +7,7 @@ #include #include -unsigned int debug_smp_processor_id(void) +notrace unsigned int debug_smp_processor_id(void) { unsigned long preempt_count = preempt_count(); int this_cpu = raw_smp_processor_id(); -- cgit v1.2.3-18-g5258 From 16444a8a40d4c7b4f6de34af0cae1f76a4f6c901 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Mon, 12 May 2008 21:20:42 +0200 Subject: ftrace: add basic support for gcc profiler instrumentation If CONFIG_FTRACE is selected and /proc/sys/kernel/ftrace_enabled is set to a non-zero value the ftrace routine will be called everytime we enter a kernel function that is not marked with the "notrace" attribute. The ftrace routine will then call a registered function if a function happens to be registered. [ This code has been highly hacked by Steven Rostedt and Ingo Molnar, so don't blame Arnaldo for all of this ;-) ] Update: It is now possible to register more than one ftrace function. If only one ftrace function is registered, that will be the function that ftrace calls directly. If more than one function is registered, then ftrace will call a function that will loop through the functions to call. Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- lib/Kconfig.debug | 2 ++ 1 file changed, 2 insertions(+) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index d2099f41aa1..d8b6279a9b4 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -634,6 +634,8 @@ config LATENCYTOP Enable this option if you want to use the LatencyTOP tool to find out which userspace is blocking on what kernel operations. +source kernel/trace/Kconfig + config PROVIDE_OHCI1394_DMA_INIT bool "Remote debugging over FireWire early on boot" depends on PCI && X86 -- cgit v1.2.3-18-g5258 From 5568b139f4d196273958ae2947a736fdf1ffeece Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 12 May 2008 21:20:44 +0200 Subject: ftrace: debug smp_processor_id, use notrace preempt disable The debug smp_processor_id caused a recursive fault in debugging the irqsoff tracer. The tracer used a smp_processor_id in the ftrace callback, and this function called preempt_disable which also is traced. This caused a recursive fault (stack overload). Since using smp_processor_id without debugging on does not cause faults with the tracer (even when the tracer is wrong), the debug version should not cause a system reboot. This changes the debug_smp_processor_id to use the notrace versions of preempt_disable and enable. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- lib/smp_processor_id.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c index e555ab62fba..3b4dc098181 100644 --- a/lib/smp_processor_id.c +++ b/lib/smp_processor_id.c @@ -37,7 +37,7 @@ notrace unsigned int debug_smp_processor_id(void) /* * Avoid recursion: */ - preempt_disable(); + preempt_disable_notrace(); if (!printk_ratelimit()) goto out_enable; @@ -49,7 +49,7 @@ notrace unsigned int debug_smp_processor_id(void) dump_stack(); out_enable: - preempt_enable_no_resched(); + preempt_enable_no_resched_notrace(); out: return this_cpu; } -- cgit v1.2.3-18-g5258 From 3594136ad67a54d77bcb2547e70011754a2f91d5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 12 May 2008 21:20:50 +0200 Subject: ftrace: do not profile lib/string.o Most archs define the string and memory compare functions in assembly. Some do not. But these functions may be used in some archs at early boot up. Since most archs define this code in assembly and they are not usually traced, there's no need to trace them when they are not defined in assembly. This patch removes the -pg from the CFLAGS for lib/string.o. This prevents the string functions use in either vdso or early bootup from crashing the system. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- lib/Makefile | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'lib') diff --git a/lib/Makefile b/lib/Makefile index 74b0cfb1fcc..6ca9e6ee1e3 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -8,6 +8,14 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ sha1.o irq_regs.o reciprocal_div.o argv_split.o \ proportions.o prio_heap.o ratelimit.o +ifdef CONFIG_FTRACE +# Do not profile string.o, since it may be used in early boot or vdso +ORIG_CFLAGS := $(KBUILD_CFLAGS) +KBUILD_CFLAGS = $(if $(subst string,,$(basename $(notdir $@))), \ + $(ORIG_CFLAGS), \ + $(subst -pg,,$(ORIG_CFLAGS))) +endif + lib-$(CONFIG_MMU) += ioremap.o lib-$(CONFIG_SMP) += cpumask.o -- cgit v1.2.3-18-g5258 From 9d0a420b737f72d84fabebf29634d800cbf54538 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 12 May 2008 21:20:55 +0200 Subject: ftrace: remove function tracing from spinlock debug The debug functions in spin_lock debugging pollute the output of the function tracer. This patch adds the debug files in the lib director to those that should not be compiled with mcount tracing. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- lib/Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/Makefile b/lib/Makefile index 6ca9e6ee1e3..d97ad1100b6 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -10,8 +10,9 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ ifdef CONFIG_FTRACE # Do not profile string.o, since it may be used in early boot or vdso +# Also do not profile any debug utilities ORIG_CFLAGS := $(KBUILD_CFLAGS) -KBUILD_CFLAGS = $(if $(subst string,,$(basename $(notdir $@))), \ +KBUILD_CFLAGS = $(if $(filter-out %debug debug% string%,$(basename $(notdir $@))), \ $(ORIG_CFLAGS), \ $(subst -pg,,$(ORIG_CFLAGS))) endif -- cgit v1.2.3-18-g5258 From 654e4787689faffdd2137fe91f59fd3ef3363ad2 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 14 May 2008 21:30:31 -0400 Subject: ftrace: use the new kbuild CFLAGS_REMOVE for lib directory This patch removes the Makefile turd and uses the nice CFLAGS_REMOVE macro in the lib directory. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- lib/Makefile | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'lib') diff --git a/lib/Makefile b/lib/Makefile index d97ad1100b6..4b836a53c08 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -10,11 +10,11 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ ifdef CONFIG_FTRACE # Do not profile string.o, since it may be used in early boot or vdso +CFLAGS_REMOVE_string.o = -pg # Also do not profile any debug utilities -ORIG_CFLAGS := $(KBUILD_CFLAGS) -KBUILD_CFLAGS = $(if $(filter-out %debug debug% string%,$(basename $(notdir $@))), \ - $(ORIG_CFLAGS), \ - $(subst -pg,,$(ORIG_CFLAGS))) +CFLAGS_REMOVE_spinlock_debug.o = -pg +CFLAGS_REMOVE_list_debug.o = -pg +CFLAGS_REMOVE_debugobjects.o = -pg endif lib-$(CONFIG_MMU) += ioremap.o -- cgit v1.2.3-18-g5258