bin/47527: time command sometimes shows garbage in "user" and "sys"

[mayuresh%acm.org@localhost]

>Number:         47527
>Category:       bin
>Synopsis:       time command sometimes shows garbage in "user" and "sys"
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Feb 03 08:25:00 +0000 2013
>Originator:     Mayuresh
>Release:        6.0
>Organization:
>Environment:
NetBSD laptop 6.0 NetBSD 6.0 (MYKERNEL) #0: Mon Dec 31 19:45:50 IST 2012  
root@laptop:/usr/src/sys/arch/i386/compile/MYKERNEL i386
>Description:
time command is _sometimes_ seen producing garbage values in "user" and "sys" 
though it produces sane "real" time values at the same time.

E.g.

real    0m0.196s
user    20m43.820s
sys     4m36.405s


>How-To-Repeat:
The exact steps are not  known, though with the procedure described in the 
following post, it can be produced with a good probability.

http://mail-index.netbsd.org/netbsd-users/2013/02/02/msg012393.html

It is also observed that the problem is easily reproducible on a job that runs 
a certain version of Java shown below. Attempt to reproduce it using a workload 
written in shell or C or some other version of Java have not succeeded.

#java -version
java version "1.6.0_33"
Java(TM) SE Runtime Environment (build 1.6.0_33-b04)
Java HotSpot(TM) Server VM (build 20.8-b03, mixed mode)

It may have something to do with a specific Java version, though time command 
is not expected to be sensitive to it and this behavior may still qualify as a 
bug.

>Fix:
Not known.