Re: [PATCH i-g-t] tests/pm_rpm tests for set_caching and set_tiling ioctl(s)

Marius Vlad
2015-11-26T10:55:24Z

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On Wed, Nov 25, 2015 at 10:08:21PM +0200, Imre Deak wrote:
> On ke, 2015-11-25 at 19:16 +0200, marius.c.vlad@intel.com wrote:
> > From: Marius Vlad <marius.c.vlad@intel.com>
> >
> > Signed-off-by: Marius Vlad <marius.c.vlad@intel.com>
> > ---
> >  tests/pm_rpm.c | 120 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 120 insertions(+)
> >
> > diff --git a/tests/pm_rpm.c b/tests/pm_rpm.c
> > index c4fb19c..157cf29 100644
> > --- a/tests/pm_rpm.c
> > +++ b/tests/pm_rpm.c
> > @@ -1729,6 +1729,120 @@ static void planes_subtest(bool universal, bool dpms)
> >   }
> >  }
> >
> > +static void pm_test_tiling(void)
> > +{
> > + uint32_t *handles;
> > + uint8_t **gem_bufs;
> > +
> > + int max_gem_objs = 0;
> > + uint8_t off_bit = 20;
> > + uint32_t gtt_obj_max_size = (16 * 1024 * 1024);
> > +
> > + uint32_t i, j, tiling_modes[3] = {
> > + I915_TILING_NONE,
> > + I915_TILING_X,
> > + I915_TILING_Y,
> > + };
> > + uint32_t ti, sw;
> > +
> > + /* default value */
> > + uint32_t stride = 1024;
> > +
> > + /* calculate how many objects we can map */
> > + for (j = 1 << off_bit; j <= gtt_obj_max_size; j <<= 1, max_gem_objs++)
> > + ;
>
> With these sizes we may end up with all objects properly aligned,
> that's why I suggested smaller objects. Based on I830_FENCE_START_MASK
> we could allocate for example starting from 16kB to 256kB.
>

Initially, I've tried with smaller sizes, but the assertion(s) failed.
I'll try as you suggested.

> > +
> > + gem_bufs = calloc(max_gem_objs, sizeof(uint8_t *));
> > + handles = malloc(sizeof(uint32_t) * max_gem_objs);
>
> Nitpick: sizeof(*ptr) is safer and you could've used calloc in both
> cases.

Indeed.

>
> > +
> > + /* map to gtt and store some random data */
> > + for (i = 0, j = 1 << off_bit; j <= gtt_obj_max_size; j <<= 1, i++) {
> > + handles[i] = gem_create(drm_fd, j);
> > + gem_bufs[i] = gem_mmap__gtt(drm_fd, handles[i], j, PROT_WRITE);
> > + memset(gem_bufs[i], 0x65, j);
> > + }
> > +
> > + /* try to set different tiling for each handle */
> > + for (i = 0; i < ARRAY_SIZE(tiling_modes); i++) {
> > + disable_all_screens_and_wait(&ms_data);
> > +
> > + for (j = 0; j < max_gem_objs; j++) {
> > + gem_set_tiling(drm_fd, handles[j], tiling_modes[i], stride);
> > +
> > + gem_get_tiling(drm_fd, handles[j], &ti, &sw);
> > + igt_assert(tiling_modes[i] == ti);
> > + }
> > +
> > + enable_one_screen_and_wait(&ms_data);
>
> Ok, but after the second iteration all objects could be properly
> aligned, so it's better to close/realloc/memset the objects in each
> iteration.

Alright. I'll do that.

>
> > + }
> > +
> > + for (i = 0, j = 1 << off_bit; j <= gtt_obj_max_size; j <<= 1, i++) {
> > + igt_assert(munmap(gem_bufs[i], j) == 0);
> > + gem_close(drm_fd, handles[i]);
> > + }
> > +
> > + free(gem_bufs);
> > + free(handles);
> > +}
> > +
> > +static void pm_test_caching(void)
> > +{
> > + uint32_t *handles;
> > + uint8_t **gem_bufs;
> > + int8_t has_caching_display = -1;
> > +
> > + uint32_t i, j, got_caching;
> > + uint32_t gtt_obj_max_size = (16 * 1024 * 1024);
> > + uint32_t cache_levels[3] = {
> > + I915_CACHING_NONE,
> > + I915_CACHING_CACHED, /* LLC caching */
> > + I915_CACHING_DISPLAY, /* eDRAM caching */
> > + };
> > +
> > + int max_gem_objs = 0;
> > + uint8_t off_bit = 20;
> > +
> > + for (j = 1 << off_bit; j <= gtt_obj_max_size; j <<= 1, max_gem_objs++)
> > + ;
>
> No need to bother about alignment here, so we can just use a single
> 16kB object for example.

Alright.

>
> > +
> > + gem_bufs = calloc(max_gem_objs, sizeof(uint8_t *));
> > + handles = malloc(sizeof(uint32_t) * max_gem_objs);
> > +
> > + for (i = 0, j = 1 << off_bit; j <= gtt_obj_max_size; j <<= 1, i++) {
> > + handles[i] = gem_create(drm_fd, j);
> > + gem_bufs[i] = gem_mmap__gtt(drm_fd, handles[i], j, PROT_WRITE);
> > + memset(gem_bufs[i], 0x65, j);
> > + }
> > +
> > + /* figure out if we have cache display available on the platform */
> > + gem_set_caching(drm_fd, handles[0], I915_CACHING_DISPLAY);
> > + if (gem_get_caching(drm_fd, handles[0]))
>
> No need to hardcode I915_CACHING_NONE here. Also I liked the original
> version to check this everywhere better, by accepting both
> CACHING_DISPLAY and CACHING_NONE as a result.

I don't think I get it.

As far as I understand CACHING_DISPLAY will fall-back to CACHING_NONE if
the platform doesn't have support for it. Is there a proper way to check
for this?
igt_require()/igt_skip_on()/igt_require_f() can indeed be used to bypass
certain test(s), but there has to be a way to determine apriori if (indeed)
the platform supports CACHING_DISPLAY, before asserting the status.

Most likely this kind of issue has come up in other circumstances...

>
> > + has_caching_display++;
> > +
> > + for (i = 0; i < ARRAY_SIZE(cache_levels) + has_caching_display; i++) {
> > + disable_all_screens_and_wait(&ms_data);
> > +
> > + for (j = 0; j < max_gem_objs; j++) {
> > + gem_set_caching(drm_fd, handles[j], cache_levels[i]);
> > +
> > + igt_debug("Verying cache for handle %u, level %u\n", j, i);
> > + got_caching = gem_get_caching(drm_fd, handles[j]);
> > +
> > + igt_assert(got_caching == cache_levels[i]);
> > + }
> > +
> > + enable_one_screen_and_wait(&ms_data);
>
> The object can be unbound after the IOCTL so you need to do a memset at
> the begin of each iteration.

Okay. Will redo and send another try. Thanks for taking to time to
review!.

>
> > + }
> > +
> > + for (i = 0, j = 1 << off_bit; j <= gtt_obj_max_size; j <<= 1, i++) {
> > + igt_assert(munmap(gem_bufs[i], j) == 0);
> > + gem_close(drm_fd, handles[i]);
> > + }
> > +
> > + free(handles);
> > + free(gem_bufs);
> > +}
> > +
> >  static void fences_subtest(bool dpms)
> >  {
> >   int i;
> > @@ -1927,6 +2041,12 @@ int main(int argc, char *argv[])
> >   igt_subtest("gem-execbuf-stress-extra-wait")
> >   gem_execbuf_stress_subtest(rounds, WAIT_STATUS | WAIT_EXTRA);
> >
> > + /* power-wake reference tests */
> > + igt_subtest("pm-tiling")
> > + pm_test_tiling();
> > + igt_subtest("pm-caching")
> > + pm_test_caching();
> > +
> >   igt_fixture
> >   teardown_environment();
> >

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