[Intel-gfx] [PATCH 2/3] tests/gem_close_race: Adapt the test for Full PPGTT

[Ben Widawsky]

On Tue, Dec 10, 2013 at 01:32:13PM +0100, Daniel Vetter wrote:
> On Tue, Dec 10, 2013 at 09:36:22AM +0000, oscar.mateo at intel.com wrote:
> > From: Oscar Mateo <oscar.mateo at intel.com>
> > 
> > With Full PPGTT, each new fd creates a new context and thus a new
> > PPGTT, so we have to reduce the number of simultaneous fds or face
> > OOM problems. For every new PPGTT, its PDEs are stored in the GGTT
> > which imposes a limit of 1024 new contexts. We want to leave at
> > least 1/4 of the GGTT available for "important" stuff like scanout
> > buffers, so never open more than 768 fds.
> > 
> > Signed-off-by: Oscar Mateo <oscar.mateo at intel.com>
> 
> This test hasn't been terribly effective at provoking the bug it tries to
> hit, so I think we can just unconditionally use the lower limit. That also
> helps with the really long runtime of this case a bit.
> -Daniel

FWIW, all 3 of these patches, or their equivalents were in the branch I
sent in my cover letter.

My implementation on this specifically was slightly different. Same
idea.

> 
> > ---
> >  tests/gem_close_race.c |   39 ++++++++++++++++++++++++++-------------
> >  1 file changed, 26 insertions(+), 13 deletions(-)
> > 
> > diff --git a/tests/gem_close_race.c b/tests/gem_close_race.c
> > index 6064c02..f658c90 100644
> > --- a/tests/gem_close_race.c
> > +++ b/tests/gem_close_race.c
> > @@ -49,6 +49,8 @@
> >  
> >  static char device[80];
> >  static uint32_t devid;
> > +static unsigned int num_childs = 2000;
> > +static unsigned int num_fds = 32000;
> >  
> >  static void selfcopy(int fd, uint32_t handle, int loops)
> >  {
> > @@ -136,11 +138,10 @@ static void run(int child)
> >  		gem_read(fd, handle, 0, &handle, sizeof(handle));
> >  }
> >  
> > -#define NUM_FD 32000
> > -
> >  struct thread {
> >  	pthread_mutex_t mutex;
> > -	int fds[NUM_FD];
> > +	unsigned int num_fds;
> > +	int *fds;
> >  	int done;
> >  };
> >  
> > @@ -152,7 +153,7 @@ static void *thread_run(void *_data)
> >  	while (!t->done) {
> >  		pthread_mutex_unlock(&t->mutex);
> >  
> > -		for (int n = 0; n < NUM_FD; n++) {
> > +		for (int n = 0; n < t->num_fds; n++) {
> >  			struct drm_i915_gem_create create;
> >  
> >  			create.handle = 0;
> > @@ -185,7 +186,7 @@ static void *thread_busy(void *_data)
> >  
> >  		pthread_mutex_unlock(&t->mutex);
> >  
> > -		n  = rand() % NUM_FD;
> > +		n  = rand() % t->num_fds;
> >  
> >  		create.handle = 0;
> >  		create.size = OBJECT_SIZE;
> > @@ -213,16 +214,23 @@ igt_main
> >  {
> >  	igt_skip_on_simulation();
> >  
> > -	sprintf(device, "/dev/dri/card%d", drm_get_card());
> > -	{
> > -		int fd = open(device, O_RDWR);
> > +	igt_fixture {
> > +		int fd;
> > +		sprintf(device, "/dev/dri/card%d", drm_get_card());
> > +		fd = open(device, O_RDWR);
> >  		igt_assert(fd != -1);
> >  		devid = intel_get_drm_devid(fd);
> > +		if (gem_uses_full_ppgtt(fd))
> > +		{
> > +			/* Reduce the number of simultaneous fds or face OOM */
> > +			num_childs = 768;
> > +			num_fds = 768;
> > +		}
> >  		close(fd);
> >  	}
> >  
> >  	igt_subtest("process-exit") {
> > -		igt_fork(child, 2000)
> > +		igt_fork(child, num_childs)
> >  			run(child);
> >  		igt_waitchildren();
> >  	}
> > @@ -232,17 +240,21 @@ igt_main
> >  		struct thread *data = calloc(1, sizeof(struct thread));
> >  		int n;
> >  
> > +		data->num_fds = num_fds;
> > +		data->fds = calloc(num_fds, sizeof(int));
> > +
> >  		igt_assert(data);
> > +		igt_assert(data->fds);
> >  
> >  		pthread_mutex_init(&data->mutex, NULL);
> > -		for (n = 0; n < NUM_FD; n++)
> > +		for (n = 0; n < num_fds; n++)
> >  			data->fds[n] = open(device, O_RDWR);
> >  
> >  		pthread_create(&thread[0], NULL, thread_run, data);
> >  		pthread_create(&thread[1], NULL, thread_busy, data);
> >  
> > -		for (n = 0; n < 1000*NUM_FD; n++) {
> > -			int i = rand() % NUM_FD;
> > +		for (n = 0; n < 1000*num_fds; n++) {
> > +			int i = rand() % num_fds;
> >  			if (data->fds[i] == -1) {
> >  				data->fds[i] = open(device, O_RDWR);
> >  			} else{
> > @@ -258,8 +270,9 @@ igt_main
> >  		pthread_join(thread[1], NULL);
> >  		pthread_join(thread[0], NULL);
> >  
> > -		for (n = 0; n < NUM_FD; n++)
> > +		for (n = 0; n < num_fds; n++)
> >  			close(data->fds[n]);
> > +		free(data->fds);
> >  		free(data);
> >  	}
> >  }
> > -- 
> > 1.7.9.5
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx at lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch

-- 
Ben Widawsky, Intel Open Source Technology Center