[oracle@rac01 trace]$ tail -f orcl1_vktm_5046.trc
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28483)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28477)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28471)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28465)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28459)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28453)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28447)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28441)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28435)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28429)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28423)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28417)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28411)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28405)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28399)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28393)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28387)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28381)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28375)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28369)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28363)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28357)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28351)microsecs at 1445066092
kstmchkdrift (kstmhighrestimecntkeeper:lowres): Time moved backward by (28345)microsecs at 1445066092

Cause

The issue has been investigated by development in the following bug:

Bug 9843304 - VKTM TRACE FILE IS FILLING UP WITH KSTMCHKDRIFT "BACKWARD DRIFT ENDED AT"  (for 11.2.0.1)

 Bug 11837095 "TIME DRIFT DETECTED" APPEARS INTERMITTENTLY IN ALERT LOG, THO' EVENT 10795 SET  (for 11.2.0.2 and 11.2.0.3)

Solution

1 For version 11.2.0.1, Apply patch for Bug 9843304.  This Bug is already fixed in 11.2.0.2

For 11.2.0.2 and 11.2.0.3, apply patch for Bug 11837095, This Bug is already fixed in 11.2.0.4

If the patch is not available for your platform, please log a Service Request with Oracle Support and request one.

2-The patch adds the ability to disable this debugging information. 
To actually disable the debugging information after applying the patch, add the following event in the init.ora/pfile for the instance:
event="10795 trace name context forever, level 2"