mutex.tp.diff

commit 873b53923069d5dc50b0a54348987a48e1b7a7ba
Author: Noah Watkins <noahwatkins@gmail.com>
Date:   Fri May 30 14:13:12 2014 -0700

    tracing: bootstrap lttng-ust with mutex events
    
    See src/tracing/README.md
    
    Signed-off-by: Noah Watkins <noahwatkins@gmail.com>

diff --git a/configure.ac b/configure.ac
index 0703eb9..822bb26 100644
--- a/configure.ac
+++ b/configure.ac
@@ -801,6 +801,7 @@ AC_CONFIG_FILES([Makefile
 	src/ocf/ceph
 	src/ocf/rbd
 	src/java/Makefile
+	src/tracing/Makefile
 	man/Makefile
 	ceph.spec])
 AC_OUTPUT
diff --git a/src/Makefile-env.am b/src/Makefile-env.am
index e33f8cc..9e603bb 100644
--- a/src/Makefile-env.am
+++ b/src/Makefile-env.am
@@ -153,6 +153,7 @@ LIBRBD = librbd.la
 LIBKRBD = libkrbd.la
 LIBCEPHFS = libcephfs.la
 LIBERASURE_CODE = liberasure_code.la
+LIBTRACEPOINTS = tracing/libtracepoints.la
 
 if WITH_LIBAIO
 LIBOS += -laio
diff --git a/src/Makefile.am b/src/Makefile.am
index 3501a7c..b0abf7e 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,7 +1,7 @@
 include Makefile-env.am
 
-SUBDIRS += ocf java
-DIST_SUBDIRS += gtest ocf libs3 java
+SUBDIRS += ocf java tracing
+DIST_SUBDIRS += gtest ocf libs3 java tracing
 
 
 # subdirs
diff --git a/src/common/Makefile.am b/src/common/Makefile.am
index bb5c43f..c0f65d1 100644
--- a/src/common/Makefile.am
+++ b/src/common/Makefile.am
@@ -111,7 +111,8 @@ noinst_HEADERS += \
 LIBCOMMON_DEPS += \
 	$(LIBERASURE_CODE) \
 	$(LIBMSG) $(LIBAUTH) \
-	$(LIBCRUSH) $(LIBJSON_SPIRIT) $(LIBLOG) $(LIBARCH)
+	$(LIBCRUSH) $(LIBJSON_SPIRIT) $(LIBLOG) $(LIBARCH) \
+	$(LIBTRACEPOINTS)
 
 if LINUX
 LIBCOMMON_DEPS += -lrt
diff --git a/src/common/Mutex.cc b/src/common/Mutex.cc
index f1e9a55..0a407f9 100644
--- a/src/common/Mutex.cc
+++ b/src/common/Mutex.cc
@@ -19,6 +19,7 @@
 #include "common/config.h"
 #include "include/utime.h"
 #include "common/Clock.h"
+#include "tracing/mutex.tp.h"
 
 Mutex::Mutex(const char *n, bool r, bool ld,
 	     bool bt,
@@ -77,20 +78,35 @@ Mutex::~Mutex() {
 }
 
 void Mutex::Lock(bool no_lockdep) {
+  utime_t start;
+  int r;
+
+  tracepoint(mutex, lock_enter, this, name);
+
   if (lockdep && g_lockdep && !no_lockdep) _will_lock();
 
   if (TryLock()) {
-    return;
+    goto out;
   }
 
-  utime_t start;
   if (logger && cct && cct->_conf->mutex_perf_counter)
     start = ceph_clock_now(cct);
-  int r = pthread_mutex_lock(&_m);
+  r = pthread_mutex_lock(&_m);
   if (logger && cct && cct->_conf->mutex_perf_counter)
     logger->tinc(l_mutex_wait,
 		 ceph_clock_now(cct) - start);
   assert(r == 0);
   if (lockdep && g_lockdep) _locked();
   _post_lock();
+
+out:
+  tracepoint(mutex, lock_exit, this, name);
+}
+
+void Mutex::Unlock() {
+  _pre_unlock();
+  if (lockdep && g_lockdep) _will_unlock();
+  int r = pthread_mutex_unlock(&_m);
+  assert(r == 0);
+  tracepoint(mutex, unlock, this, name);
 }
diff --git a/src/common/Mutex.h b/src/common/Mutex.h
index e26a090..e2ebe1f 100644
--- a/src/common/Mutex.h
+++ b/src/common/Mutex.h
@@ -101,12 +101,7 @@ public:
       assert(nlock == 0);
     }
   }
-  void Unlock() {
-    _pre_unlock();
-    if (lockdep && g_lockdep) _will_unlock();
-    int r = pthread_mutex_unlock(&_m);
-    assert(r == 0);
-  }
+  void Unlock();
 
   friend class Cond;
 
diff --git a/src/tracing/Makefile.am b/src/tracing/Makefile.am
new file mode 100644
index 0000000..f759a6a
--- /dev/null
+++ b/src/tracing/Makefile.am
@@ -0,0 +1,8 @@
+libtracepoints_la_SOURCES = \
+	mutex.tp.c \
+	mutex.tp.h
+
+libtracepoints_la_LIBADD = -llttng-ust -ldl
+libtracepoints_la_CPPFLAGS = -DTRACEPOINT_PROBE_DYNAMIC_LINKAGE
+libtracepoints_la_LDFLAGS =
+noinst_LTLIBRARIES = libtracepoints.la
diff --git a/src/tracing/README.md b/src/tracing/README.md
new file mode 100644
index 0000000..1c86eb3
--- /dev/null
+++ b/src/tracing/README.md
@@ -0,0 +1,32 @@
+Add New Provider
+================
+
+## Create tracepoint definition file
+
+Add tracepoint definitions for the provider into a `.tp` file. Documentation
+on defining a tracepoint can be found in `man lttng-ust`. By convention files
+are named according to the logical sub-system they correspond to (e.g.
+`mutex.tp`, `pg.tp`).
+
+## Generate tracepoint source files
+
+The `.tp` file is converted into source files using the `lttng-gen-tp` tool.
+
+    lttng-gen-tp mutex.tp -o mutex.tp.h -o mutex.tp.c
+
+## Add source files to libtracepoints.la
+
+Modify Makefile.am to include the generated source files from the previous
+step.
+
+## Commit changes to Git
+
+Commit both the source `.tp` file as well as the generated sources, and the
+changes to Makefile.am.
+
+Add Tracepoint to Existing Provider
+===================================
+
+New tracepoints can be added to an existing provider by updating the
+corresponding `.tp` file and re-generating the source files. Make sure to
+commit the updated files back into Git.
diff --git a/src/tracing/mutex.tp b/src/tracing/mutex.tp
new file mode 100644
index 0000000..7cdfdb3
--- /dev/null
+++ b/src/tracing/mutex.tp
@@ -0,0 +1,29 @@
+TRACEPOINT_EVENT(mutex, lock_enter,
+    TP_ARGS(
+        const void *, addr,
+        const char *, name),
+    TP_FIELDS(
+        ctf_integer_hex(unsigned long, addr, addr)
+        ctf_string(name, name)
+    )
+)
+
+TRACEPOINT_EVENT(mutex, lock_exit,
+    TP_ARGS(
+        const void *, addr,
+        const char *, name),
+    TP_FIELDS(
+        ctf_integer_hex(unsigned long, addr, addr)
+        ctf_string(name, name)
+    )
+)
+
+TRACEPOINT_EVENT(mutex, unlock,
+    TP_ARGS(
+        const void *, addr,
+        const char *, name),
+    TP_FIELDS(
+        ctf_integer_hex(unsigned long, addr, addr)
+        ctf_string(name, name)
+    )
+)
diff --git a/src/tracing/mutex.tp.c b/src/tracing/mutex.tp.c
new file mode 100644
index 0000000..1727e80
--- /dev/null
+++ b/src/tracing/mutex.tp.c
@@ -0,0 +1,7 @@
+
+#define TRACEPOINT_CREATE_PROBES
+/*
+ * The header containing our TRACEPOINT_EVENTs.
+ */
+#define TRACEPOINT_DEFINE
+#include "mutex.tp.h"
diff --git a/src/tracing/mutex.tp.h b/src/tracing/mutex.tp.h
new file mode 100644
index 0000000..e26e86d
--- /dev/null
+++ b/src/tracing/mutex.tp.h
@@ -0,0 +1,45 @@
+
+#undef TRACEPOINT_PROVIDER
+#define TRACEPOINT_PROVIDER mutex
+
+#undef TRACEPOINT_INCLUDE
+#define TRACEPOINT_INCLUDE "./mutex.tp.h"
+
+#if !defined(MUTEX_TP_H) || defined(TRACEPOINT_HEADER_MULTI_READ)
+#define MUTEX_TP_H
+
+#include <lttng/tracepoint.h>
+
+TRACEPOINT_EVENT(mutex, lock_enter,
+    TP_ARGS(
+        const void *, addr,
+        const char *, name),
+    TP_FIELDS(
+        ctf_integer_hex(unsigned long, addr, addr)
+        ctf_string(name, name)
+    )
+)
+
+TRACEPOINT_EVENT(mutex, lock_exit,
+    TP_ARGS(
+        const void *, addr,
+        const char *, name),
+    TP_FIELDS(
+        ctf_integer_hex(unsigned long, addr, addr)
+        ctf_string(name, name)
+    )
+)
+
+TRACEPOINT_EVENT(mutex, unlock,
+    TP_ARGS(
+        const void *, addr,
+        const char *, name),
+    TP_FIELDS(
+        ctf_integer_hex(unsigned long, addr, addr)
+        ctf_string(name, name)
+    )
+)
+
+#endif /* MUTEX_TP_H */
+
+#include <lttng/tracepoint-event.h>