[LTP] [PATCH v2] times03: don't assume process initial [us]time is 0

[Jan Stancek <jstancek@redhat.com>]

----- Original Message -----
> On Fri, Mar 9, 2018 at 3:29 PM, Jan Stancek <jstancek@redhat.com> wrote:
> 
> > times() runs immediately after fork(), but syscall alone
> > seems to be enough for some systems to already account ticks.
> >
> > For example on arm64 with 4.14:
> >   tst_test.c:980: INFO: Timeout per run is 0h 05m 00s
> >   times03.c:102: PASS: buf1.tms_utime = 0
> >   times03.c:105: FAIL: buf1.tms_stime = 1
> >   ...
> >
> > This patch replaces zero check with a comparison against a small
> > enough number < 5 (which should be between 5ms and 50ms depending
> > on CONFIG_HZ).
> >
> > Suggested-by: Cyril Hrubis <chrubis@suse.cz>
> > Signed-off-by: Jan Stancek <jstancek@redhat.com>
> > ---
> >  testcases/kernel/syscalls/times/times03.c | 8 ++++----
> >  1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/testcases/kernel/syscalls/times/times03.c
> > b/testcases/kernel/syscalls/times/times03.c
> > index 78d72d259ec1..c34faf5a2ff9 100644
> > --- a/testcases/kernel/syscalls/times/times03.c
> > +++ b/testcases/kernel/syscalls/times/times03.c
> > @@ -96,15 +96,15 @@ static void verify_times(void)
> >         if (times(&buf1) == -1)
> >                 tst_brk(TBROK | TERRNO, "times()");
> >
> > -       if (buf1.tms_utime != 0)
> > +       if (buf1.tms_utime > 5)
> >                 tst_res(TFAIL, "buf1.tms_utime = %li", buf1.tms_utime);
> >         else
> > -               tst_res(TPASS, "buf1.tms_utime = 0");
> > +               tst_res(TPASS, "
> > ​​
> > buf1.tms_utime > 5");
> >
> 
> ​shouldn't this ​buf1.tms_utime <= 5 ?​

You're right, the TPASS message is wrong.

> 
> 
> 
> >
> > -       if (buf1.tms_stime != 0)
> > +       if (buf1.tms_stime > 5)
> >                 tst_res(TFAIL, "buf1.tms_stime = %li", buf1.tms_stime);
> >         else
> > -               tst_res(TPASS, "buf1.tms_stime = 0");
> > +               tst_res(TPASS, "buf1.tms_stime > 5");
> >
> 
> ​here as well.
> ​
> 
> 
> >
> >         generate_utime();
> >         generate_stime();
> > --
> > 1.8.3.1
> >
> >
> ​Other than that this looks good to me. I also run this changes more than
> 100 times and ​all passed.
>