Re: [platform-testers] [Grep-devel] new snapshot available: grep-2.25.101-be82

[Bruce Dubbs]

Jim Meyering wrote:
> On Mon, Sep 26, 2016 at 10:04 AM, Bruce Dubbs <address@hidden> wrote:
> > Jim Meyering wrote:
> > > On Sun, Sep 25, 2016 at 11:27 PM, Bruce Dubbs <address@hidden>
> > > wrote:
> > > > >      http://meyering.net/grep/grep-2.25.101-be82.tar.xz
> > >
> > > ...
> > > > Builds clean with gcc-5.3.0.
> >
> >
> > > Thank you for the quick testing and the reports.
> >
> >
> > When I ran the expensive tests I had a failure.
> > FAIL long-pattern-perf (exit status: 1)
> >
> > It appears to be a timing issue.
> >
> > $ lscpu
> > Architecture:          x86_64
> > CPU op-mode(s):        32-bit, 64-bit
> > Byte Order:            Little Endian
> > CPU(s):                4
> > On-line CPU(s) list:   0-3
> > Thread(s) per core:    1
> > Core(s) per socket:    4
> > Socket(s):             1
> > NUMA node(s):          1
> > Vendor ID:             GenuineIntel
> > CPU family:            6
> > Model:                 94
> > Model name:            Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz
> > Stepping:              3
> > CPU MHz:               3201.000
>
> Thanks for the report.
>
> How did you configure/compile that?

./configure && make && make check-very-expensive 2>&1 |tee ck.log

This test runs grep with two
> regexps. First it times the use of a shorter one, then it times the
> use of a regexp whose byte count is 10 times larger than the first
> one. The test requires that the latter duration be no longer than 20x
> the duration of the first run. In your case, it actually took 80ms
> longer than the 400ms that would be 20x.
>
> As mentioned in its comments, that test is sensitive to load and
> timing. Can you reproduce that failure consistently when running that
> test in isolation? I.e., run this a few times:
>
>    check -C tests TESTS=long-pattern-perf RUN_EXPENSIVE_TESTS=yes
>
> I may end up changing it to run the quick one 5 times, and use the
> minimum time to compare against the duration of the longer-running
> command also being run 5 times (or until passing).

Using the above, I ran it about 6 times and it only passed twice.  I do 
have several apps open but I have 'load average: 0.01, 0.06, 0.05'

$ free
              total    used    free      shared  buff/cache   available
Mem:        8051948 1724040 5279176      414404     1048732     5834340
Swap:       2097148  361760 1735388

  -- Bruce