[ltt-dev] [PATCH 1/2] Import TRACE_EVENT macro from the kernel
Nils Carlson
nils.carlson at ericsson.com
Tue Aug 24 07:04:43 EDT 2010
This is a slightly modified version of the TRACE_EVENT
macro from the kernel, TP_printf has replaced TP_printk.
The TRACE_EVENT macro expansion is currently a dummy which
only expands to a printf probe, connected in a constructor.
All copyright holders have approved, any contributions for which
approval is lacking are trivial.
---
include/ust/define_trace.h | 98 ++++++++++++++++++++++++++++++++
include/ust/kcompat/compiler.h | 1 +
include/ust/kcompat/stringify.h | 12 ++++
include/ust/tracepoint.h | 119 +++++++++++++++++++++++++++++++++++++++
include/ust/ust_trace.h | 56 ++++++++++++++++++
5 files changed, 286 insertions(+), 0 deletions(-)
create mode 100644 include/ust/define_trace.h
create mode 100644 include/ust/kcompat/stringify.h
create mode 100644 include/ust/ust_trace.h
diff --git a/include/ust/define_trace.h b/include/ust/define_trace.h
new file mode 100644
index 0000000..ec709a9
--- /dev/null
+++ b/include/ust/define_trace.h
@@ -0,0 +1,98 @@
+/*
+ * Trace files that want to automate creationg of all tracepoints defined
+ * in their file should include this file. The following are macros that the
+ * trace file may define:
+ *
+ * TRACE_SYSTEM defines the system the tracepoint is for
+ *
+ * TRACE_INCLUDE_FILE if the file name is something other than TRACE_SYSTEM.h
+ * This macro may be defined to tell define_trace.h what file to include.
+ * Note, leave off the ".h".
+ *
+ * TRACE_INCLUDE_PATH if the path is something other than core kernel include/trace
+ * then this macro can define the path to use. Note, the path is relative to
+ * define_trace.h, not the file including it. Full path names for out of tree
+ * modules must be used.
+ */
+
+#ifdef CREATE_TRACE_POINTS
+
+/* Prevent recursion */
+#undef CREATE_TRACE_POINTS
+
+#include <ust/kcompat/stringify.h>
+
+#undef TRACE_EVENT
+#define TRACE_EVENT(name, proto, args, tstruct, assign, print) \
+ DEFINE_TRACE(name)
+
+#undef TRACE_EVENT_FN
+#define TRACE_EVENT_FN(name, proto, args, tstruct, \
+ assign, print, reg, unreg) \
+ DEFINE_TRACE_FN(name, reg, unreg)
+
+#undef DEFINE_EVENT
+#define DEFINE_EVENT(template, name, proto, args) \
+ DEFINE_TRACE(name)
+
+#undef DEFINE_EVENT_PRINT
+#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
+ DEFINE_TRACE(name)
+
+#undef DECLARE_TRACE
+#define DECLARE_TRACE(name, proto, args) \
+ DEFINE_TRACE(name)
+
+#undef TRACE_INCLUDE
+#undef __TRACE_INCLUDE
+
+#ifndef TRACE_INCLUDE_FILE
+# define TRACE_INCLUDE_FILE TRACE_SYSTEM
+# define UNDEF_TRACE_INCLUDE_FILE
+#endif
+
+#ifndef TRACE_INCLUDE_PATH
+# define __TRACE_INCLUDE(system) <trace/events/system.h>
+# define UNDEF_TRACE_INCLUDE_PATH
+#else
+# define __TRACE_INCLUDE(system) __stringify(TRACE_INCLUDE_PATH/system.h)
+#endif
+
+# define TRACE_INCLUDE(system) __TRACE_INCLUDE(system)
+
+/* Let the trace headers be reread */
+#define TRACE_HEADER_MULTI_READ
+
+#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
+
+/* Make all open coded DECLARE_TRACE nops */
+#undef DECLARE_TRACE
+#define DECLARE_TRACE(name, proto, args)
+
+#ifndef CONFIG_NO_EVENT_TRACING
+#include <ust/ust_trace.h>
+#endif
+
+#undef TRACE_EVENT
+#undef TRACE_EVENT_FN
+#undef DECLARE_EVENT_CLASS
+#undef DEFINE_EVENT
+#undef DEFINE_EVENT_PRINT
+#undef TRACE_HEADER_MULTI_READ
+#undef DECLARE_TRACE
+
+/* Only undef what we defined in this file */
+#ifdef UNDEF_TRACE_INCLUDE_FILE
+# undef TRACE_INCLUDE_FILE
+# undef UNDEF_TRACE_INCLUDE_FILE
+#endif
+
+#ifdef UNDEF_TRACE_INCLUDE_PATH
+# undef TRACE_INCLUDE_PATH
+# undef UNDEF_TRACE_INCLUDE_PATH
+#endif
+
+/* We may be processing more files */
+#define CREATE_TRACE_POINTS
+
+#endif /* CREATE_TRACE_POINTS */
diff --git a/include/ust/kcompat/compiler.h b/include/ust/kcompat/compiler.h
index d3ef8a1..f2fbd3e 100644
--- a/include/ust/kcompat/compiler.h
+++ b/include/ust/kcompat/compiler.h
@@ -34,6 +34,7 @@
#define __printf(a,b) __attribute__((format(printf,a,b)))
#define noinline __attribute__((noinline))
#define __attribute_const__ __attribute__((__const__))
+#define __used __attribute__((used))
#define __maybe_unused __attribute__((unused))
#define notrace __attribute__((no_instrument_function))
diff --git a/include/ust/kcompat/stringify.h b/include/ust/kcompat/stringify.h
new file mode 100644
index 0000000..841cec8
--- /dev/null
+++ b/include/ust/kcompat/stringify.h
@@ -0,0 +1,12 @@
+#ifndef __LINUX_STRINGIFY_H
+#define __LINUX_STRINGIFY_H
+
+/* Indirect stringification. Doing two levels allows the parameter to be a
+ * macro itself. For example, compile with -DFOO=bar, __stringify(FOO)
+ * converts to "bar".
+ */
+
+#define __stringify_1(x...) #x
+#define __stringify(x...) __stringify_1(x)
+
+#endif /* !__LINUX_STRINGIFY_H */
diff --git a/include/ust/tracepoint.h b/include/ust/tracepoint.h
index be35f92..3409585 100644
--- a/include/ust/tracepoint.h
+++ b/include/ust/tracepoint.h
@@ -43,6 +43,8 @@ struct tracepoint {
* Keep in sync with vmlinux.lds.h.
*/
+#define PARAMS(args...) args
+
#define TP_PROTO(args...) args
#define TP_ARGS(args...) args
@@ -206,4 +208,121 @@ extern int tracepoint_unregister_lib(struct tracepoint *tracepoints_start);
tracepoint_unregister_lib(__start___tracepoints); \
}
+
+#ifndef TRACE_EVENT
+/*
+ * For use with the TRACE_EVENT macro:
+ *
+ * We define a tracepoint, its arguments, its printf format
+ * and its 'fast binary record' layout.
+ *
+ * Firstly, name your tracepoint via TRACE_EVENT(name : the
+ * 'subsystem_event' notation is fine.
+ *
+ * Think about this whole construct as the
+ * 'trace_sched_switch() function' from now on.
+ *
+ *
+ * TRACE_EVENT(sched_switch,
+ *
+ * *
+ * * A function has a regular function arguments
+ * * prototype, declare it via TP_PROTO():
+ * *
+ *
+ * TP_PROTO(struct rq *rq, struct task_struct *prev,
+ * struct task_struct *next),
+ *
+ * *
+ * * Define the call signature of the 'function'.
+ * * (Design sidenote: we use this instead of a
+ * * TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.)
+ * *
+ *
+ * TP_ARGS(rq, prev, next),
+ *
+ * *
+ * * Fast binary tracing: define the trace record via
+ * * TP_STRUCT__entry(). You can think about it like a
+ * * regular C structure local variable definition.
+ * *
+ * * This is how the trace record is structured and will
+ * * be saved into the ring buffer. These are the fields
+ * * that will be exposed to readers.
+ * *
+ * * The declared 'local variable' is called '__entry'
+ * *
+ * * __field(pid_t, prev_prid) is equivalent to a standard declariton:
+ * *
+ * * pid_t prev_pid;
+ * *
+ * * __array(char, prev_comm, TASK_COMM_LEN) is equivalent to:
+ * *
+ * * char prev_comm[TASK_COMM_LEN];
+ * *
+ *
+ * TP_STRUCT__entry(
+ * __array( char, prev_comm, TASK_COMM_LEN )
+ * __field( pid_t, prev_pid )
+ * __field( int, prev_prio )
+ * __array( char, next_comm, TASK_COMM_LEN )
+ * __field( pid_t, next_pid )
+ * __field( int, next_prio )
+ * ),
+ *
+ * *
+ * * Assign the entry into the trace record, by embedding
+ * * a full C statement block into TP_fast_assign(). You
+ * * can refer to the trace record as '__entry' -
+ * * otherwise you can put arbitrary C code in here.
+ * *
+ * * Note: this C code will execute every time a trace event
+ * * happens, on an active tracepoint.
+ * *
+ *
+ * TP_fast_assign(
+ * memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
+ * __entry->prev_pid = prev->pid;
+ * __entry->prev_prio = prev->prio;
+ * memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
+ * __entry->next_pid = next->pid;
+ * __entry->next_prio = next->prio;
+ * )
+ *
+ * *
+ * * Formatted output of a trace record via TP_printf().
+ * * This is how the tracepoint will appear under debugging
+ * * of tracepoints.
+ * *
+ * * (raw-binary tracing wont actually perform this step.)
+ * *
+ *
+ * TP_printf("task %s:%d [%d] ==> %s:%d [%d]",
+ * __entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
+ * __entry->next_comm, __entry->next_pid, __entry->next_prio),
+ *
+ * );
+ *
+ * This macro construct is thus used for the regular printf format
+ * tracing setup.
+ *
+ * A set of (un)registration functions can be passed to the variant
+ * TRACE_EVENT_FN to perform any (un)registration work.
+ */
+
+#define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
+#define DEFINE_EVENT(template, name, proto, args) \
+ DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
+ DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+
+#define TRACE_EVENT(name, proto, args, struct, assign, print) \
+ DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+#define TRACE_EVENT_FN(name, proto, args, struct, \
+ assign, print, reg, unreg) \
+ DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+
+#endif /* ifdef TRACE_EVENT (see note above) */
+
+
#endif /* _UST_TRACEPOINT_H */
diff --git a/include/ust/ust_trace.h b/include/ust/ust_trace.h
new file mode 100644
index 0000000..d1a0e17
--- /dev/null
+++ b/include/ust/ust_trace.h
@@ -0,0 +1,56 @@
+/*
+ * This whole file is currently a dummy, mapping a TRACE_EVENT
+ * to a printf
+ */
+
+/*
+ * Stage 1. Create a struct and a printf calling function
+ * that is connected to the tracepoint at load time.
+ */
+#undef TRACE_EVENT
+#define TRACE_EVENT(name, proto, args, tstruct, assign, print) \
+ DECLARE_EVENT_CLASS(name, \
+ PARAMS(proto), \
+ PARAMS(args), \
+ PARAMS(tstruct), \
+ PARAMS(assign), \
+ PARAMS(print)); \
+ DEFINE_EVENT(name, name, PARAMS(proto), PARAMS(args));
+
+#undef __field
+#define __field(type, item) type item;
+
+#undef TP_STRUCT__entry
+#define TP_STRUCT__entry(args...) args
+
+#undef TP_printf
+#define TP_printf(fmt, args...) fmt "\n", args
+
+#undef TP_fast_assign
+#define TP_fast_assign(args...) args
+
+#undef DEFINE_EVENT
+#define DEFINE_EVENT(template, name, proto, args)
+
+
+#undef DECLARE_EVENT_CLASS
+#define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print) \
+ struct trace_raw_##name { \
+ tstruct \
+ }; \
+ static void trace_printf_##name(proto) \
+ { \
+ struct trace_raw_##name entry_struct, *__entry; \
+ __entry = &entry_struct; \
+ { assign }; \
+ \
+ printf(print); \
+ } \
+ static void __attribute__((constructor)) init_##name() \
+ { \
+ printf("connecting tracepoint " #name "\n"); \
+ register_trace_##name(trace_printf_##name); \
+ }
+
+
+#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
--
1.7.1
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