[LTP] [PATCH] commans/sar: Add new testcases for sar

[Cyril Hrubis <chrubis@suse.cz>]

Hi!
> +TCID=sar01
> +TST_TOTAL=19
> +. test.sh
> +
> +setup()
> +{
> +	tst_check_cmds sar
> +
> +	tst_tmpdir
> +}
> +
> +cleanup()
> +{
> +	tst_rmdir
> +}
> +
> +sar_test()
> +{
> +	$1 >${TCID}.temp 2>&1

Since we call tst_tmpdir() in setup we are guaranteed to be executed in
unique temorary directory. So we can just do:

$1 >temp 2>&1

And we do not need to worry about some other test rewriting our file.

> +	if [ $? -ne 0 ]; then
> +		tst_resm TFAIL "'$1' failed."
> +		return
> +	fi
> +
> +	grep $2 ${TCID}.temp >/dev/null

Grep has -q (quiet) switch.

> +	if [ $? -eq 0 ]; then
> +		tst_resm TPASS "'$1' passed."
> +	else
> +		tst_resm TFAIL "'$1' failed."
> +	fi

Grepping one word is pretty loose criteria for pass/fail for a program
that actually prints several pages of statistics.

A few things that can be done here are:

* Number of cpus is detected correctly

* The CPU load sums to 100%


More complicated tests can also do:

* Run a program with bussy loop on a background and check that
  it consumes CPU cycles (load at least 100/NCPU over all cpus)

* Run a program that reads and writes files on background
  and check that corresponding I/O statistics are reasonable

* ...


Getting this right would require substantial amount of effort, but
as this test is now it's not much useful as it would pass even if sar
was broken really badly.

-- 
Cyril Hrubis
chrubis@suse.cz