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author | 2020-01-29 16:19:10 -0500 | |
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committer | 2020-01-30 09:46:29 -0500 | |
commit | 61778cd70c1dcef082e5ee6781c7c0c4d7d5b576 (patch) | |
tree | e8429a22c0b5fbe21f92dd96acf85aee649d6078 | |
parent | tracing: Documentation for in-kernel synthetic event API (diff) | |
download | linux-61778cd70c1dcef082e5ee6781c7c0c4d7d5b576.tar.gz linux-61778cd70c1dcef082e5ee6781c7c0c4d7d5b576.tar.bz2 linux-61778cd70c1dcef082e5ee6781c7c0c4d7d5b576.zip |
tracing: Move all function tracing configs together
The features that depend on the function tracer were spread out through the
tracing menu, pull them together as it is easier to manage.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-rw-r--r-- | kernel/trace/Kconfig | 142 |
1 files changed, 71 insertions, 71 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 4484e783f68d..32fcbc00753b 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -172,6 +172,77 @@ config FUNCTION_GRAPH_TRACER the return value. This is done by setting the current return address on the current task structure into a stack of calls. +config DYNAMIC_FTRACE + bool "enable/disable function tracing dynamically" + depends on FUNCTION_TRACER + depends on HAVE_DYNAMIC_FTRACE + default y + help + This option will modify all the calls to function tracing + dynamically (will patch them out of the binary image and + replace them with a No-Op instruction) on boot up. During + compile time, a table is made of all the locations that ftrace + can function trace, and this table is linked into the kernel + image. When this is enabled, functions can be individually + enabled, and the functions not enabled will not affect + performance of the system. + + See the files in /sys/kernel/debug/tracing: + available_filter_functions + set_ftrace_filter + set_ftrace_notrace + + This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but + otherwise has native performance as long as no tracing is active. + +config DYNAMIC_FTRACE_WITH_REGS + def_bool y + depends on DYNAMIC_FTRACE + depends on HAVE_DYNAMIC_FTRACE_WITH_REGS + +config DYNAMIC_FTRACE_WITH_DIRECT_CALLS + def_bool y + depends on DYNAMIC_FTRACE + depends on HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + +config FUNCTION_PROFILER + bool "Kernel function profiler" + depends on FUNCTION_TRACER + default n + help + This option enables the kernel function profiler. A file is created + in debugfs called function_profile_enabled which defaults to zero. + When a 1 is echoed into this file profiling begins, and when a + zero is entered, profiling stops. A "functions" file is created in + the trace_stat directory; this file shows the list of functions that + have been hit and their counters. + + If in doubt, say N. + +config STACK_TRACER + bool "Trace max stack" + depends on HAVE_FUNCTION_TRACER + select FUNCTION_TRACER + select STACKTRACE + select KALLSYMS + help + This special tracer records the maximum stack footprint of the + kernel and displays it in /sys/kernel/debug/tracing/stack_trace. + + This tracer works by hooking into every function call that the + kernel executes, and keeping a maximum stack depth value and + stack-trace saved. If this is configured with DYNAMIC_FTRACE + then it will not have any overhead while the stack tracer + is disabled. + + To enable the stack tracer on bootup, pass in 'stacktrace' + on the kernel command line. + + The stack tracer can also be enabled or disabled via the + sysctl kernel.stack_tracer_enabled + + Say N if unsure. + config TRACE_PREEMPT_TOGGLE bool help @@ -410,30 +481,6 @@ config BRANCH_TRACER Say N if unsure. -config STACK_TRACER - bool "Trace max stack" - depends on HAVE_FUNCTION_TRACER - select FUNCTION_TRACER - select STACKTRACE - select KALLSYMS - help - This special tracer records the maximum stack footprint of the - kernel and displays it in /sys/kernel/debug/tracing/stack_trace. - - This tracer works by hooking into every function call that the - kernel executes, and keeping a maximum stack depth value and - stack-trace saved. If this is configured with DYNAMIC_FTRACE - then it will not have any overhead while the stack tracer - is disabled. - - To enable the stack tracer on bootup, pass in 'stacktrace' - on the kernel command line. - - The stack tracer can also be enabled or disabled via the - sysctl kernel.stack_tracer_enabled - - Say N if unsure. - config BLK_DEV_IO_TRACE bool "Support for tracing block IO actions" depends on SYSFS @@ -531,53 +578,6 @@ config DYNAMIC_EVENTS config PROBE_EVENTS def_bool n -config DYNAMIC_FTRACE - bool "enable/disable function tracing dynamically" - depends on FUNCTION_TRACER - depends on HAVE_DYNAMIC_FTRACE - default y - help - This option will modify all the calls to function tracing - dynamically (will patch them out of the binary image and - replace them with a No-Op instruction) on boot up. During - compile time, a table is made of all the locations that ftrace - can function trace, and this table is linked into the kernel - image. When this is enabled, functions can be individually - enabled, and the functions not enabled will not affect - performance of the system. - - See the files in /sys/kernel/debug/tracing: - available_filter_functions - set_ftrace_filter - set_ftrace_notrace - - This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but - otherwise has native performance as long as no tracing is active. - -config DYNAMIC_FTRACE_WITH_REGS - def_bool y - depends on DYNAMIC_FTRACE - depends on HAVE_DYNAMIC_FTRACE_WITH_REGS - -config DYNAMIC_FTRACE_WITH_DIRECT_CALLS - def_bool y - depends on DYNAMIC_FTRACE - depends on HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS - -config FUNCTION_PROFILER - bool "Kernel function profiler" - depends on FUNCTION_TRACER - default n - help - This option enables the kernel function profiler. A file is created - in debugfs called function_profile_enabled which defaults to zero. - When a 1 is echoed into this file profiling begins, and when a - zero is entered, profiling stops. A "functions" file is created in - the trace_stat directory; this file shows the list of functions that - have been hit and their counters. - - If in doubt, say N. - config BPF_KPROBE_OVERRIDE bool "Enable BPF programs to override a kprobed function" depends on BPF_EVENTS |