diff --git a/ChangeLog b/ChangeLog
index 2789228a..00836fb0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -20,6 +20,10 @@ Fernando Lopez-Lezcano
   Jackdmp changes log
 ---------------------------
 
+2008-06-04 Stephane Letz  <letz@grame.fr>
+
+	*  Use of set_threaded_log_function only when needed in RT threads.
+
 2008-06-02 Stephane Letz  <letz@grame.fr>
 
 	*  Tim Blechmann patch to remove unnecessary virtual methods : choice of the appropriate platform version is now done at compilation time.
diff --git a/common/JackClient.cpp b/common/JackClient.cpp
index c5c36bce..e44311a4 100644
--- a/common/JackClient.cpp
+++ b/common/JackClient.cpp
@@ -340,6 +340,9 @@ bool JackClient::Execute()
 {
     if (!jack_tls_set(gRealTime, this)) 
         jack_error("failed to set thread realtime key");
+        
+    if (GetEngineControl()->fRealTime) 
+        set_threaded_log_function(); 
     
     if (fThreadFun) {
         // Execute a dummy cycle to be sure thread has the correct properties (ensure thread creation is finished)
diff --git a/common/JackError.cpp b/common/JackError.cpp
index c465ebe7..a3bf1349 100644
--- a/common/JackError.cpp
+++ b/common/JackError.cpp
@@ -63,9 +63,7 @@ void jack_log_function(int level, const char *message)
     log_callback(message);
 }
 
-static
-void 
-jack_format_and_log(int level, const char *prefix, const char *fmt, va_list ap)
+static void jack_format_and_log(int level, const char *prefix, const char *fmt, va_list ap)
 {
     char buffer[300];
     size_t len;
diff --git a/common/JackPosixThread.cpp b/common/JackPosixThread.cpp
index 940444d3..a44f2b14 100644
--- a/common/JackPosixThread.cpp
+++ b/common/JackPosixThread.cpp
@@ -40,8 +40,6 @@ void* JackPosixThread::ThreadHandler(void* arg)
         jack_error("pthread_setcanceltype err = %s", strerror(err));
     }
     
-    set_threaded_log_function(); 
-    
     // Signal creation thread when started with StartSync
     jack_log("ThreadHandler: start");
     obj->fStatus = kIniting;
diff --git a/common/JackThreadedDriver.cpp b/common/JackThreadedDriver.cpp
index 802097f1..253bbefe 100644
--- a/common/JackThreadedDriver.cpp
+++ b/common/JackThreadedDriver.cpp
@@ -108,8 +108,11 @@ bool JackThreadedDriver::Init()
             jack_log("JackThreadedDriver::Init IsRealTime");
             // Will do "something" on OSX only...
             fThread.SetParams(GetEngineControl()->fPeriod, GetEngineControl()->fComputation, GetEngineControl()->fConstraint);
-            if (fThread.AcquireRealTime(GetEngineControl()->fPriority) < 0)
+            if (fThread.AcquireRealTime(GetEngineControl()->fPriority) < 0) {
                 jack_error("AcquireRealTime error");
+            } else {
+                set_threaded_log_function(); 
+            }
         }
         return true;
     } else {
diff --git a/linux/alsa/alsa_rawmidi.c b/linux/alsa/alsa_rawmidi.c
index 1a82a3b9..601078f4 100644
--- a/linux/alsa/alsa_rawmidi.c
+++ b/linux/alsa/alsa_rawmidi.c
@@ -837,6 +837,9 @@ void *midi_thread(void *arg)
 	pfds[0].events = POLLIN|POLLERR|POLLNVAL;
 	npfds = 1;
 
+ 	if (jack_is_realtime(midi->client))
+	    set_threaded_log_function(); 	
+
 	//debug_log("midi_thread(%s): enter", str->name);
 
 	while (midi->keep_walking) {
diff --git a/macosx/JackMachThread.cpp b/macosx/JackMachThread.cpp
index 66b585f1..7ed47760 100644
--- a/macosx/JackMachThread.cpp
+++ b/macosx/JackMachThread.cpp
@@ -39,7 +39,7 @@ int JackMachThread::SetThreadToPriority(pthread_t thread, UInt32 inPriority, Boo
         theTCPolicy.constraint = AudioConvertNanosToHostTime(constraint);
         theTCPolicy.preemptible = true;
         kern_return_t res = thread_policy_set(pthread_mach_thread_np(thread), THREAD_TIME_CONSTRAINT_POLICY, (thread_policy_t) & theTCPolicy, THREAD_TIME_CONSTRAINT_POLICY_COUNT);
-        jack_log("JackMachThread::thread_policy_set %ld", res);
+        jack_log("JackMachThread::thread_policy_set res = %ld", res);
         return (res == KERN_SUCCESS) ? 0 : -1;
     } else {
         // OTHER THREADS
@@ -62,7 +62,7 @@ int JackMachThread::SetThreadToPriority(pthread_t thread, UInt32 inPriority, Boo
 
         thePrecedencePolicy.importance = relativePriority;
         kern_return_t res = thread_policy_set(pthread_mach_thread_np(thread), THREAD_PRECEDENCE_POLICY, (thread_policy_t) & thePrecedencePolicy, THREAD_PRECEDENCE_POLICY_COUNT);
-        jack_log("JackMachThread::thread_policy_set %ld", res);
+        jack_log("JackMachThread::thread_policy_set res = %ld", res);
         return (res == KERN_SUCCESS) ? 0 : -1;
     }
 }
diff --git a/windows/JackWinThread.cpp b/windows/JackWinThread.cpp
index 20e91472..de133c83 100644
--- a/windows/JackWinThread.cpp
+++ b/windows/JackWinThread.cpp
@@ -34,9 +34,7 @@ DWORD WINAPI JackWinThread::ThreadHandler(void* arg)
 {
     JackWinThread* obj = (JackWinThread*)arg;
     JackRunnableInterface* runnable = obj->fRunnable;
-
-    set_threaded_log_function(); 
-    
+   
     // Signal creation thread when started with StartSync
     jack_log("ThreadHandler: start");
     obj->fStatus = kIniting;