Fix test timeout: common.funcs.t_dtrace_contrib.tst_cleanpath_d

[lwhsu]

Summary

We added too many variable assignments in BEGIN block, and out of default auto
configured variable buffer space. The test VM has 4G RAM which should be enough
for most cases so it's reasonable to increase limitation to these cases.

Test Plan

cd /usr/tests/cddl/usr.sbin/dtrace && kyua debug common/funcs/t_dtrace_contrib:tst_cleanpath_d

[ngie]

LGTM at least, but markj might have some input that needs to be considered here.

[markj]

Sorry for being picky, but could you paste the output of this test without the change?

[lwhsu]

In D11674#242525, @markj wrote:

Sorry for being picky, but could you paste the output of this test without the change?

There is nothing out stdout, the error messages from kyua are as following:

lwhsu@FreeBSD-12-t:/usr/tests/cddl/usr.sbin/dtrace/common/funcs > sudo kyua debug t_dtrace_contrib:tst_cleanpath_d
Executing command [ /usr/tests/cddl/usr.sbin/dtrace/common/funcs/../../dtest /usr/tests/cddl/usr.sbin/dtrace/common/funcs/tst.cleanpath.d ]
Files left in work directory after failure: check.yRFnvD, tmp.aqs1o8zp, tmp.gL6Bm0MG
t_dtrace_contrib:tst_cleanpath_d  ->  broken: Test case body timed out

If we execute tst.cleanpath.d directly:

lwhsu@FreeBSD-12-t:/usr/tests/cddl/usr.sbin/dtrace/common/funcs > sudo dtrace -C -s tst.cleanpath.d
dtrace: buffer size lowered to 2m
dtrace: 1 dynamic variable drop
(hangs)

[markj]

In D11674#242531, @lwhsu wrote:

In D11674#242525, @markj wrote:

Sorry for being picky, but could you paste the output of this test without the change?

There is nothing out stdout, the error messages from kyua are as following:

Thanks. This is a bit surprising. How many CPUs does the system have?

[lwhsu]

In D11674#242561, @markj wrote:

Thanks. This is a bit surprising. How many CPUs does the system have?

Two: https://github.com/freebsd/freebsd-ci/blob/master/jobs/FreeBSD-head-amd64-dtrace_test/build.sh#L25

And I am thinking changing to 1 to make more room for other jobs in the future.