commit Stephen Hemminger's Linux theading improvements

AUTHORS

@@ -26,3 +26,5 @@ John Estabrook <jestabro@ncsa.uiuc.edu>
 Andrew Gallatin <gallatin@gmail.com>
   * threading fix and non Linux performance improvements
 
+Stephen Hemminger <shemminger@linux-foundation.org>
+  * Linux scheduler selection and theading improvements

ChangeLog

@@ -1,3 +1,7 @@
+2008-03-19 Stephen Hemminger <shemminger@linux-foundation.org>
+
+* Use sched_yield rather than usleep(0) as it behaves better on Linux
+
 2008-03-12 Jon Dugan <jdugan@x1024.net>
 
 * Rework Client::RunTCP so to update the stats for every packet if -i is set.

compat/Thread.c

@@ -405,9 +405,12 @@ int thread_numuserthreads( void ) {
 void thread_rest ( void ) {
 #if defined( HAVE_THREAD )
 #if defined( HAVE_POSIX_THREAD )
-    // TODO add checks for sched_yield or pthread_yield and call that
-    // if available
+#if defined( _POSIX_PRIORITY_SCHEDULING )
+    sched_yield();
+#else
     usleep( 0 );
+#endif
+
 #else // Win32
     SwitchToThread( );
 #endif