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8741db532e
linux/kernel/trace
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Steven Rostedt 8741db532e tracing/fgraph: Add max_graph_depth to limit function_graph depth 
Add the file max_graph_depth to the debug tracing directory that lets
the user define the depth of the function graph.

A very useful operation is to set the depth to 1. Then it traces only
the first function that is called when entering the kernel. This can
be used to determine what system operations interrupt a process.

For example, to work on NOHZ processes (single tasks running without
a timer tick), if any interrupt goes off and preempts that task, this
code will show it happening.

  # cd /sys/kernel/debug/tracing
  # echo 1 > max_graph_depth
  # echo function_graph > current_tracer
  # cat per_cpu/cpu/<cpu-of-process>/trace

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-01-21 13:22:34 -05:00
..
blktrace.c tracing: Use this_cpu_ptr per-cpu helper 2013-01-21 13:22:30 -05:00
ftrace.c ftrace: Be first to run code modification on modules 2013-01-21 13:21:50 -05:00
Kconfig tracing: Use irq_work for wake ups and remove *_nowake_*() functions 2012-11-02 10:21:52 -04:00
Makefile trace: Stop compiling in trace_clock unconditionally 2012-09-13 22:52:08 -04:00
power-traces.c perf: Clean up power events by introducing new, more generic ones 2011-01-04 08:16:54 +01:00
ring_buffer_benchmark.c tracing: Use NUMA allocation for per-cpu ring buffer pages 2011-06-14 22:04:39 -04:00
ring_buffer.c ring-buffer: Remove unnecessary recusive call in rb_advance_iter() 2013-01-21 13:22:29 -05:00
rpm-traces.c PM / Runtime: Introduce trace points for tracing rpm_* functions 2011-09-27 22:53:27 +02:00
trace_branch.c tracing: Cache comms only after an event occurred 2012-10-31 16:45:31 -04:00
trace_clock.c tracing: Add a counter clock for those that do not trust clocks 2011-09-19 11:35:58 -04:00
trace_entries.h Merge branch 'tip/perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/urgent 2012-03-24 08:19:09 +01:00
trace_event_perf.c perf/core improvements and fixes: 2012-08-21 11:27:00 +02:00
trace_events_filter_test.h tracing/filter: Add startup tests for events filter 2011-08-19 14:35:59 -04:00
trace_events_filter.c tracing: Replace strict_strto* with kstrto* 2012-10-31 16:45:23 -04:00
trace_events.c tracing: Use irq_work for wake ups and remove *_nowake_*() functions 2012-11-02 10:21:52 -04:00
trace_export.c tracing: Do not enable function event with enable 2012-05-10 15:55:43 -04:00
trace_functions_graph.c tracing/fgraph: Add max_graph_depth to limit function_graph depth 2013-01-21 13:22:34 -05:00
trace_functions.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-12-13 12:00:02 -08:00
trace_irqsoff.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-12-13 12:00:02 -08:00
trace_kdb.c kdb,ftdump: Remove reference to internal kdb include 2010-10-22 15:34:11 -05:00
trace_kprobe.c tracing: Use irq_work for wake ups and remove *_nowake_*() functions 2012-11-02 10:21:52 -04:00
trace_mmiotrace.c atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
trace_nop.c
trace_output.c tracing: Format non-nanosec times from tsc clock without a decimal point. 2012-11-13 15:48:40 -05:00
trace_output.h tracing: Allow events to share their print functions 2010-05-14 14:20:32 -04:00
trace_printk.c tracing: Add percpu buffers for trace_printk() 2012-04-23 21:15:55 -04:00
trace_probe.c tracing: Replace strict_strto* with kstrto* 2012-10-31 16:45:23 -04:00
trace_probe.h tracing: Provide trace events interface for uprobes 2012-05-07 14:30:17 +02:00
trace_sched_switch.c tracing: Use irq_work for wake ups and remove *_nowake_*() functions 2012-11-02 10:21:52 -04:00
trace_sched_wakeup.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-12-13 12:00:02 -08:00
trace_selftest_dynamic.c ftrace: Add self-tests for multiple function trace users 2011-05-18 19:24:51 -04:00
trace_selftest.c tracing: Use irq_work for wake ups and remove *_nowake_*() functions 2012-11-02 10:21:52 -04:00
trace_stack.c tracing: Remove unneeded checks from the stack tracer 2012-11-19 15:07:13 -05:00
trace_stat.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
trace_stat.h
trace_syscalls.c tracing/syscalls: Make local functions static 2013-01-21 13:22:31 -05:00
trace_uprobe.c tracing: Verify target file before registering a uprobe event 2013-01-21 13:22:31 -05:00
trace.c tracing: Remove unneeded check of max_tr->buffer before tracing_reset 2013-01-21 13:22:33 -05:00
trace.h tracing: Format non-nanosec times from tsc clock without a decimal point. 2012-11-13 15:48:40 -05:00