Re: [PATCH] tst: Provide test for getrusage

[Lukasz Majewski <lukma@denx.de>]

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Hi Andreas,

> Hi Andreas,
> 
> > On Mär 15 2021, Lukasz Majewski wrote:
> >   
> > > diff --git a/sysdeps/unix/sysv/linux/tst-getrusage.c
> > > b/sysdeps/unix/sysv/linux/tst-getrusage.c new file mode 100644
> > > index 0000000000..068becdadb
> > > --- /dev/null
> > > +++ b/sysdeps/unix/sysv/linux/tst-getrusage.c
> > > @@ -0,0 +1,55 @@
> > > +/* Test for getrusage
> > > +   Copyright (C) 2021 Free Software Foundation, Inc.
> > > +   This file is part of the GNU C Library.
> > > +
> > > +   The GNU C Library is free software; you can redistribute it
> > > and/or
> > > +   modify it under the terms of the GNU Lesser General Public
> > > +   License as published by the Free Software Foundation; either
> > > +   version 2.1 of the License, or (at your option) any later
> > > version. +
> > > +   The GNU C Library is distributed in the hope that it will be
> > > useful,
> > > +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > > +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > > GNU
> > > +   Lesser General Public License for more details.
> > > +
> > > +   You should have received a copy of the GNU Lesser General
> > > Public
> > > +   License along with the GNU C Library; if not, see
> > > +   <https://www.gnu.org/licenses/>.  */
> > > +
> > > +#include <time.h>
> > > +#include <sys/resource.h>
> > > +#include <support/check.h>
> > > +#include <support/timespec.h>
> > > +
> > > +#define TST_GETRUSAGE_TIMEOUT 1
> > > +
> > > +static int
> > > +do_test (void)
> > > +{
> > > +  struct timespec tv_then, tv_now, gru_u, gru_s, s, r;
> > > +  struct rusage ru;
> > > +  int ret;
> > > +
> > > +  tv_then = xclock_now (CLOCK_REALTIME);
> > > +  /* Busy wait for 1 second.  */
> > > +  do
> > > +  {
> > > +    tv_now = xclock_now (CLOCK_REALTIME);
> > > +    r = timespec_sub (tv_now, tv_then);
> > > +  } while ( r.tv_sec != TST_GETRUSAGE_TIMEOUT );    
> > 
> > What happens if the process stalls for a second?  
> 
> I think that the glibc's test infrastructure will kill it - the
> default timeout is 2 seconds.
> 
> As a result the test will fail.

On the other hand - the proposed approach with busy waiting was the
natural one to check if accounting from getrusage is correct.

Maybe you (or anybody else from the community) have a better idea on how
to force the process to be "running" (active) for some time?

Maybe I could modify the C test code to perform following bash
operation:
cat /dev/urandom | gzip -9 > /dev/null

and replace /dev/urandom with some large (generated in place) file?
However, this would pose additional dependencies (gzip) on glibc test
suite.

> 
> > 
> > Andreas.
> >   
> 
> 
> 
> 
> Best regards,
> 
> Lukasz Majewski
> 
> --
> 
> DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email:
> lukma@denx.de




Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de

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