LTP - gettimeofday02 FAIL

From: Paul Larson (plars@linuxtestproject.org)
Date: Tue Nov 12 2002 - 17:11:14 EST


I've been getting a somewhat random error in a few of the recent 2.5
kernels with SMP machines. I noticed this on a 2.5.47 bk pull, but I
was also able to reproduce it on 2.5.46. I haven't tried any earlier
kernels yet. The LTP gettimeofday02 test sometimes fails with this
message:
gettimeofday02 0 INFO : checking if gettimeofday is monotonous,
takes 30s
gettimeofday02 1 FAIL : Time is going backwards (old
1037138184.846333 vs new 1037138184.843346!

I have not been able to reproduce this on a single processor machine
though.

Basically, all the test does is:
gettimeofday(&tv1, NULL);
while(!done) {
        gettimeofday(&tv2, NULL);
        FAIL if tv2 < tv1
        tv1 = tv2;
}

Any ideas on what could be causing this?

Thanks,
Paul Larson



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