Description of problem:

Seeing lots of these:

Mar 13 10:45:38 hammer kernel: Timer ISR/0: Time went backwards: delta=10704325
cpu_delta=-13295675 shadow=1498014236562 off=368468468 processed=1498372000000
cpu_processed=1498396000000
Mar 13 10:45:38 hammer kernel: Timer ISR/0: Time went backwards: delta=713653
cpu_delta=-3286347 shadow=1498014236562 off=378477489 processed=1498392000000
cpu_processed=1498396000000
Mar 13 10:45:45 hammer kernel: Timer ISR/0: Time went backwards: delta=6718011
cpu_delta=-29281989 shadow=1504014291147 off=648427706 processed=1504656000000
cpu_processed=1504692000000
Mar 13 10:45:45 hammer kernel: Timer ISR/0: Time went backwards: delta=714067
cpu_delta=-19285933 shadow=1504014291147 off=658423273 processed=1504672000000
cpu_processed=1504692000000
Mar 13 10:45:45 hammer kernel: Timer ISR/0: Time went backwards: delta=2719206
cpu_delta=-9280794 shadow=1504014291147 off=668428389 processed=1504680000000
cpu_processed=1504692000000
Mar 13 10:45:53 hammer kernel: Timer ISR/0: Time went backwards: delta=10205669
cpu_delta=-1794331 shadow=1513014376517 off=247829870 processed=1513252000000
cpu_processed=1513264000000
Mar 13 10:45:55 hammer kernel: Timer ISR/0: Time went backwards: delta=2984517
cpu_delta=-5015483 shadow=1515014435224 off=128549792 processed=1515140000000
cpu_processed=1515148000000
Mar 13 10:49:17 hammer kernel: Timer ISR/0: Time went backwards: delta=4762455
cpu_delta=-3237545 shadow=1717016980266 off=323782829 processed=1717336000000
cpu_processed=1717344000000


Version-Release number of selected component (if applicable):
2.6.15-1.2041_FC5xen0

also seen with 2038_FC5xen0