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authorSteven Rostedt <rostedt@goodmis.org>2008-11-12 05:14:40 (GMT)
committerIngo Molnar <mingo@elte.hu>2008-11-12 10:52:02 (GMT)
commit52f232cb720a7babb752849cbc2cab2d24021209 (patch)
tree47c7e800549457bd5ab9b54f47729acac6e10780 /kernel/trace/Makefile
parent1f0d69a9fc815db82f15722bf05227190b1d714d (diff)
downloadlinux-52f232cb720a7babb752849cbc2cab2d24021209.tar.xz
tracing: likely/unlikely branch annotation tracer
Impact: new likely/unlikely branch tracer This patch adds a way to record the instances of the likely() and unlikely() branch condition annotations. When "unlikely" is set in /debugfs/tracing/iter_ctrl the unlikely conditions will be added to any of the ftrace tracers. The change takes effect when a new tracer is passed into the current_tracer file. For example: bash-3471 [003] 357.014755: [INCORRECT] sched_info_dequeued:sched_stats.h:177 bash-3471 [003] 357.014756: [correct] update_curr:sched_fair.c:489 bash-3471 [003] 357.014758: [correct] calc_delta_fair:sched_fair.c:411 bash-3471 [003] 357.014759: [correct] account_group_exec_runtime:sched_stats.h:356 bash-3471 [003] 357.014761: [correct] update_curr:sched_fair.c:489 bash-3471 [003] 357.014763: [INCORRECT] calc_delta_fair:sched_fair.c:411 bash-3471 [003] 357.014765: [correct] calc_delta_mine:sched.c:1279 Which shows the normal tracer heading, as well as whether the condition was correct "[correct]" or was mistaken "[INCORRECT]", followed by the function, file name and line number. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace/Makefile')
-rw-r--r--kernel/trace/Makefile6
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 98e70ee..c938d03 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -10,6 +10,12 @@ CFLAGS_trace_selftest_dynamic.o = -pg
obj-y += trace_selftest_dynamic.o
endif
+# If unlikely tracing is enabled, do not trace these files
+ifdef CONFIG_TRACING_UNLIKELY
+KBUILD_CFLAGS += '-Dlikely(x)=likely_notrace(x)'
+KBUILD_CFLAGS += '-Dunlikely(x)=unlikely_notrace(x)'
+endif
+
obj-$(CONFIG_FUNCTION_TRACER) += libftrace.o
obj-$(CONFIG_RING_BUFFER) += ring_buffer.o