svn commit: r264821 - stable/10/sys/kern

[Alexander Motin]

Author: mav
Date: Wed Apr 23 12:46:27 2014
New Revision: 264821
URL: http://svnweb.freebsd.org/changeset/base/264821

Log:
  MFC r264550:
  Fix VIRTUAL and PROF interval timers for short intervals, broken at r247903.
  
  Due to the way those timers are implemented, we can't handle very short
  intervals.  In addition to that mentioned patch caused math overflows
  for short intervals.  To avoid that round those intervals to 1 tick.
  
  PR:		kern/187668

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

Modified: stable/10/sys/kern/kern_time.c
==============================================================================
--- stable/10/sys/kern/kern_time.c	Wed Apr 23 12:16:36 2014	(r264820)
+++ stable/10/sys/kern/kern_time.c	Wed Apr 23 12:46:27 2014	(r264821)
@@ -774,6 +774,14 @@ kern_setitimer(struct thread *td, u_int 
 				timevalsub(&oitv->it_value, &ctv);
 		}
 	} else {
+		if (aitv->it_interval.tv_sec == 0 &&
+		    aitv->it_interval.tv_usec != 0 &&
+		    aitv->it_interval.tv_usec < tick)
+			aitv->it_interval.tv_usec = tick;
+		if (aitv->it_value.tv_sec == 0 &&
+		    aitv->it_value.tv_usec != 0 &&
+		    aitv->it_value.tv_usec < tick)
+			aitv->it_value.tv_usec = tick;
 		PROC_SLOCK(p);
 		*oitv = p->p_stats->p_timer[which];
 		p->p_stats->p_timer[which] = *aitv;