Re: [PATCH 1/3] tests/pm_rps: ducttape for igt fork helper cleanup issues

[Jeff McGee <jeff.mcgee@intel.com>]

On Fri, Mar 14, 2014 at 10:27:46AM +0100, Daniel Vetter wrote:
> We don't call cleanup handlers when exiting a subtest currently, only
> when exiting the entire binary. Which means pm_rps falls over when it
> fails more than one subtest.
> 
> Cc: Jeff McGee <jeff.mcgee@intel.com>
> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> ---
>  tests/pm_rps.c | 32 +++++++++++++++++++-------------
>  1 file changed, 19 insertions(+), 13 deletions(-)
> 
> diff --git a/tests/pm_rps.c b/tests/pm_rps.c
> index a652cf580dc7..b1cd13fc33a7 100644
> --- a/tests/pm_rps.c
> +++ b/tests/pm_rps.c
> @@ -196,9 +196,27 @@ static void emit_store_dword_imm(uint32_t val)
>  }
>  
>  #define LOAD_HELPER_PAUSE_USEC 500
> +static void load_helper_set_load(enum load load)
> +{
> +	assert(lh.igt_proc.running);
> +
> +	if (lh.load == load)
> +		return;
> +
> +	lh.load = load;
> +	kill(lh.igt_proc.pid, SIGUSR2);
> +}
> +
>  static void load_helper_run(enum load load)
>  {
> -	assert(!lh.igt_proc.running);
> +	/*
> +	 * FIXME fork helpers won't get cleaned up when started from within a
> +	 * subtest, so handle the case where it sticks around a bit too long.
> +	 */
> +	if (lh.igt_proc.running) {
> +		load_helper_set_load(load);
> +		return;
> +	}
>  
>  	igt_require(lh.ready == true);
>  
> @@ -229,20 +247,8 @@ static void load_helper_run(enum load load)
>  	}
>  }
>  
> -static void load_helper_set_load(enum load load)
> -{
> -	assert(lh.igt_proc.running);
> -
> -	if (lh.load == load)
> -		return;
> -
> -	lh.load = load;
> -	kill(lh.igt_proc.pid, SIGUSR2);
> -}
> -
>  static void load_helper_stop(void)
>  {
> -	assert(lh.igt_proc.running);
>  	kill(lh.igt_proc.pid, SIGUSR1);
>  	igt_wait_helper(&lh.igt_proc);
>  }
> -- 
> 1.8.4.rc3
> 

Unfortunately there are probably several ways in which a failed subtest will
contaminate subsequent subtests if all are run in the same process instance.
I asked about that earlier and you said that we don't concern too much about
it because the preferred way to run is with a test runner and each subtest
executed in a separate instance. If we do in fact care about supporting all
subtests in a single instance, can we put in place a subtest exit handler?
That would solve all issues similar to this.
-Jeff