Test scenario for sysctl kern.maxfiles

[Alan Somers]

On Wed, Mar 5, 2014 at 1:58 AM, Peter Holm <peter at holm.cc> wrote:
> Here's an attempt to verify that increasing kern.maxfiles works as
> expected.
>
> http://people.freebsd.org/~pho/kern_descrip_test-v3.diff
> --
> Peter

1) done should be of type "static volatile sig_atomic_t", not int,
because it's set by signal handlers.

2) using atexit() to register a cleanup routing is a hack.  No doubt
you already noticed that it's difficult to use Kyua's builtin cleanup
capabilities because of the need to pass the value of oldmaxfiles.  I
too have experienced that frustration.  Is there any way to pass
values from the body of a testcase to its cleanup?  Using
atf_tc_set_md_var() would be one way, but the man page suggests that
that function cannot be called from the body.  Julio, is there a
better way to do this?

3) Why do you openfiles(oldmaxfiles + 50, 0) instead of just
openfiles(oldmaxfiles) ?  It seems that the latter would also verify
the assertion.

4) openfiles(oldmaxfiles + 50, 0) will fail if there are already 950
open files.  A quick check on freefall showed that kern.openfiles was
935.  Perhaps you should try opening openfiles(oldmaxfiles -
kern.openfiles + 50, 0).  That wouldn't be perfect, due to races, but
it would be better.

-Alan