svn commit: r316843 - stable/10/sys/kern

[Andriy Gapon]

Author: avg
Date: Fri Apr 14 14:45:44 2017
New Revision: 316843
URL: https://svnweb.freebsd.org/changeset/base/316843

Log:
  MFC r315960: dtrace sched:::preempt should fire only when there is preemption

Modified:
  stable/10/sys/kern/kern_synch.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/kern/kern_synch.c
==============================================================================
--- stable/10/sys/kern/kern_synch.c	Fri Apr 14 14:45:39 2017	(r316842)
+++ stable/10/sys/kern/kern_synch.c	Fri Apr 14 14:45:44 2017	(r316843)
@@ -462,7 +462,11 @@ mi_switch(int flags, struct thread *newt
 	PCPU_SET(switchticks, ticks);
 	CTR4(KTR_PROC, "mi_switch: old thread %ld (td_sched %p, pid %ld, %s)",
 	    td->td_tid, td->td_sched, td->td_proc->p_pid, td->td_name);
-	SDT_PROBE0(sched, , , preempt);
+#ifdef KDTRACE_HOOKS
+	if ((flags & SW_PREEMPT) != 0 || ((flags & SW_INVOL) != 0 &&
+	    (flags & SW_TYPE_MASK) == SWT_NEEDRESCHED))
+		SDT_PROBE0(sched, , , preempt);
+#endif
 #ifdef XEN
 	PT_UPDATES_FLUSH();
 #endif