On Fri, 2016-09-30 at 11:49 +0200, Michal Hocko wrote: > [CC Mike and Mel as they have seen some accounting oddities > when doing performance testing. They can share details but > essentially the system time just gets too high] > > For your reference the email thread started > http://lkml.kernel.org/r/20160823143330.GL23577@xxxxxxxxxxxxxx > > I suspect this is mainly for short lived processes - like kernel > compile > $ /usr/bin/time -v make mm/mmap.o > [...] > User time (seconds): 0.45 > System time (seconds): 0.82 > Percent of CPU this job got: 111% > Elapsed (wall clock) time (h:mm:ss or m:ss): 0:01.14 > $ rm mm/mmap.o > $ /usr/bin/time -v make mm/mmap.o > [...] > User time (seconds): 0.47 > System time (seconds): 1.55 > Percent of CPU this job got: 107% > Elapsed (wall clock) time (h:mm:ss or m:ss): 0:01.88 I was not able to get the "expected" results from your last reproducer, but this one does happen on my system, too. The bad news is, I still have no clue what is causing it... -- All Rights Reversed.
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