path: root/samples
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authorLinus Torvalds <torvalds@linux-foundation.org>2009-06-20 10:56:46 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-20 10:56:46 -0700
commitb0b7065b64fe517b4a50915a1555e8ee98890d64 (patch)
tree950e7735585a83f5b4efe7a9473b5b42d5ca4f57 /samples
parent38df92b8cee936334f686c06df0e5fbb92e252df (diff)
parentd4c4038343510d83727ea922de4435996c26c0c8 (diff)
Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits) tracing/urgent: warn in case of ftrace_start_up inbalance tracing/urgent: fix unbalanced ftrace_start_up function-graph: add stack frame test function-graph: disable when both x86_32 and optimize for size are configured ring-buffer: have benchmark test print to trace buffer ring-buffer: do not grab locks in nmi ring-buffer: add locks around rb_per_cpu_empty ring-buffer: check for less than two in size allocation ring-buffer: remove useless compile check for buffer_page size ring-buffer: remove useless warn on check ring-buffer: use BUF_PAGE_HDR_SIZE in calculating index tracing: update sample event documentation tracing/filters: fix race between filter setting and module unload tracing/filters: free filter_string in destroy_preds() ring-buffer: use commit counters for commit pointer accounting ring-buffer: remove unused variable ring-buffer: have benchmark test handle discarded events ring-buffer: prevent adding write in discarded area tracing/filters: strloc should be unsigned short tracing/filters: operand can be negative ... Fix up kmemcheck-induced conflict in kernel/trace/ring_buffer.c manually
Diffstat (limited to 'samples')
2 files changed, 24 insertions, 11 deletions
diff --git a/samples/trace_events/Makefile b/samples/trace_events/Makefile
index 0d428dc6728..0f8d92120c4 100644
--- a/samples/trace_events/Makefile
+++ b/samples/trace_events/Makefile
@@ -1,6 +1,14 @@
# builds the trace events example kernel modules;
# then to use one (as root): insmod <module_name.ko>
+# If you include a trace header outside of include/trace/events
+# then the file that does the #define CREATE_TRACE_POINTS must
+# have that tracer file in its main search path. This is because
+# define_trace.h will include it, and must be able to find it from
+# the include/trace directory.
+# Here trace-events-sample.c does the CREATE_TRACE_POINTS.
CFLAGS_trace-events-sample.o := -I$(src)
obj-$(CONFIG_SAMPLE_TRACE_EVENTS) += trace-events-sample.o
diff --git a/samples/trace_events/trace-events-sample.h b/samples/trace_events/trace-events-sample.h
index 128a897687c..9977a756fb3 100644
--- a/samples/trace_events/trace-events-sample.h
+++ b/samples/trace_events/trace-events-sample.h
@@ -19,16 +19,21 @@
* If TRACE_SYSTEM is defined, that will be the directory created
* in the ftrace directory under /debugfs/tracing/events/<system>
- * The define_trace.h belowe will also look for a file name of
+ * The define_trace.h below will also look for a file name of
* TRACE_SYSTEM.h where TRACE_SYSTEM is what is defined here.
+ * In this case, it would look for sample.h
- * If you want a different system than file name, you can override
- * the header name by defining TRACE_INCLUDE_FILE
+ * If the header name will be different than the system name
+ * (as in this case), then you can override the header name that
+ * define_trace.h will look up by defining TRACE_INCLUDE_FILE
- * If this file was called, goofy.h, then we would define:
+ * This file is called trace-events-sample.h but we want the system
+ * to be called "sample". Therefore we must define the name of this
+ * file:
- * #define TRACE_INCLUDE_FILE goofy
+ * #define TRACE_INCLUDE_FILE trace-events-sample
+ * As we do an the bottom of this file.
#define TRACE_SYSTEM sample
@@ -99,13 +104,13 @@ TRACE_EVENT(foo_bar,
* #define TRACE_INCLUDE_PATH ../../samples/trace_events
- * But I chose to simply make it use the current directory and then in
- * the Makefile I added:
+ * But the safest and easiest way to simply make it use the directory
+ * that the file is in is to add in the Makefile:
- * CFLAGS_trace-events-sample.o := -I$(PWD)/samples/trace_events/
+ * CFLAGS_trace-events-sample.o := -I$(src)
* This will make sure the current path is part of the include
- * structure for our file so that we can find it.
+ * structure for our file so that define_trace.h can find it.
* I could have made only the top level directory the include:
@@ -115,8 +120,8 @@ TRACE_EVENT(foo_bar,
* #define TRACE_INCLUDE_PATH samples/trace_events
- * But then if something defines "samples" or "trace_events" then we
- * could risk that being converted too, and give us an unexpected
+ * But then if something defines "samples" or "trace_events" as a macro
+ * then we could risk that being converted too, and give us an unexpected
* result.