Re: [PATCH i-g-t 05/16] i915/gem_ctx_create: Basic checks for constructor properties

Chris Wilson
2019-05-22T10:24:11Z

Quoting Tvrtko Ursulin (2019-05-16 09:38:15)
>
> On 15/05/2019 20:05, Chris Wilson wrote:
> > Quoting Tvrtko Ursulin (2019-05-14 11:15:12)
> >>
> >> On 08/05/2019 11:09, Chris Wilson wrote:
> >>> Check that the extended create interface accepts setparam.
> >>>
> >>> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> >>> ---
> >>> tests/i915/gem_ctx_create.c | 225 ++++++++++++++++++++++++++++++++++--
> >>> 1 file changed, 213 insertions(+), 12 deletions(-)
> >>>
> >>> diff --git a/tests/i915/gem_ctx_create.c b/tests/i915/gem_ctx_create.c
> >>> index a664070db..9b4fddbe7 100644
> >>> --- a/tests/i915/gem_ctx_create.c
> >>> +++ b/tests/i915/gem_ctx_create.c
> >>> @@ -33,6 +33,7 @@
> >>> #include <time.h>
> >>>
> >>> #include "igt_rand.h"
> >>> +#include "sw_sync.h"
> >>>
> >>> #define LOCAL_I915_EXEC_BSD_SHIFT (13)
> >>> #define LOCAL_I915_EXEC_BSD_MASK (3 << LOCAL_I915_EXEC_BSD_SHIFT)
> >>> @@ -45,12 +46,33 @@ static unsigned all_nengine;
> >>> static unsigned ppgtt_engines[16];
> >>> static unsigned ppgtt_nengine;
> >>>
> >>> -static int __gem_context_create_local(int fd, struct drm_i915_gem_context_create *arg)
> >>> +static int create_ioctl(int fd, struct drm_i915_gem_context_create *arg)
> >>> {
> >>> - int ret = 0;
> >>> - if (drmIoctl(fd, DRM_IOCTL_I915_GEM_CONTEXT_CREATE, arg))
> >>> - ret = -errno;
> >>> - return ret;
> >>> + int err;
> >>> +
> >>> + err = 0;
> >>> + if (igt_ioctl(fd, DRM_IOCTL_I915_GEM_CONTEXT_CREATE, arg)) {
> >>> + err = -errno;
> >>> + igt_assert(err);
> >>> + }
> >>> +
> >>> + errno = 0;
> >>> + return err;
> >>> +}
> >>> +
> >>> +static int create_ext_ioctl(int i915,
> >>> + struct drm_i915_gem_context_create_ext *arg)
> >>> +{
> >>> + int err;
> >>> +
> >>> + err = 0;
> >>> + if (igt_ioctl(i915, DRM_IOCTL_I915_GEM_CONTEXT_CREATE_EXT, arg)) {
> >>> + err = -errno;
> >>> + igt_assume(err);
> >>> + }
> >>> +
> >>> + errno = 0;
> >>> + return err;
> >>> }
> >>>
> >>> static double elapsed(const struct timespec *start,
> >>> @@ -308,6 +330,187 @@ static void maximum(int fd, int ncpus, unsigned mode)
> >>> free(contexts);
> >>> }
> >>>
> >>> +static void basic_ext_param(int i915)
> >>> +{
> >>> + struct drm_i915_gem_context_create_ext_setparam ext = {
> >>> + { .name = I915_CONTEXT_CREATE_EXT_SETPARAM },
> >>> + };
> >>> + struct drm_i915_gem_context_create_ext create = {
> >>> + .flags = I915_CONTEXT_CREATE_FLAGS_USE_EXTENSIONS
> >>> + };
> >>> + struct drm_i915_gem_context_param get;
> >>> +
> >>> + igt_require(create_ext_ioctl(i915, &create) == 0);
> >>> + gem_context_destroy(i915, create.ctx_id);
> >>> +
> >>> + create.extensions = -1ull;
> >>> + igt_assert_eq(create_ext_ioctl(i915, &create), -EFAULT);
> >>> +
> >>> + create.extensions = to_user_pointer(&ext);
> >>> + igt_assert_eq(create_ext_ioctl(i915, &create), -EINVAL);
> >>> +
> >>> + ext.param.param = I915_CONTEXT_PARAM_PRIORITY;
> >>> + if (create_ext_ioctl(i915, &create) != -ENODEV) {
> >>> + gem_context_destroy(i915, create.ctx_id);
> >>> +
> >>> + ext.base.next_extension = -1ull;
> >>> + igt_assert_eq(create_ext_ioctl(i915, &create), -EFAULT);
> >>> + ext.base.next_extension = to_user_pointer(&ext);
> >>> + igt_assert_eq(create_ext_ioctl(i915, &create), -E2BIG);
> >>> + ext.base.next_extension = 0;
> >>> +
> >>> + ext.param.value = 32;
> >>> + igt_assert_eq(create_ext_ioctl(i915, &create), 0);
> >>> +
> >>> + memset(&get, 0, sizeof(get));
> >>> + get.ctx_id = create.ctx_id;
> >>> + get.param = I915_CONTEXT_PARAM_PRIORITY;
> >>> + gem_context_get_param(i915, &get);
> >>> + igt_assert_eq(get.value, ext.param.value);
> >>> +
> >>> + gem_context_destroy(i915, create.ctx_id);
> >>> + }
> >>> +}
> >>> +
> >>> +static void check_single_timeline(int i915, uint32_t ctx, int num_engines)
> >>> +{
> >>> +#define RCS_TIMESTAMP (0x2000 + 0x358)
> >>> + const int gen = intel_gen(intel_get_drm_devid(i915));
> >>> + const int has_64bit_reloc = gen >= 8;
> >>> + struct drm_i915_gem_exec_object2 results = { .handle = gem_create(i915, 4096) };
> >>> + const uint32_t bbe = MI_BATCH_BUFFER_END;
> >>> + int timeline = sw_sync_timeline_create();
> >>> + uint32_t last, *map;
> >>> +
> >>> + {
> >>> + struct drm_i915_gem_execbuffer2 execbuf = {
> >>> + .buffers_ptr = to_user_pointer(&results),
> >>> + .buffer_count = 1,
> >>> + .rsvd1 = ctx,
> >>> + };
> >>> + gem_write(i915, results.handle, 0, &bbe, sizeof(bbe));
> >>> + gem_execbuf(i915, &execbuf);
> >>> + results.flags = EXEC_OBJECT_PINNED;
> >>> + }
> >>> +
> >>> + for (int i = 0; i < num_engines; i++) {
> >>> + struct drm_i915_gem_exec_object2 obj[2] = {
> >>> + results, /* write hazard lies! */
> >>> + { .handle = gem_create(i915, 4096) },
> >>> + };
> >>> + struct drm_i915_gem_execbuffer2 execbuf = {
> >>> + .buffers_ptr = to_user_pointer(obj),
> >>> + .buffer_count = 2,
> >>> + .rsvd1 = ctx,
> >>> + .rsvd2 = sw_sync_timeline_create_fence(timeline, num_engines - i),
> >>> + .flags = i | I915_EXEC_FENCE_IN,
> >>> + };
> >>> + uint64_t offset = results.offset + 4 * i;
> >>> + uint32_t *cs;
> >>> + int j = 0;
> >>> +
> >>> + cs = gem_mmap__cpu(i915, obj[1].handle, 0, 4096, PROT_WRITE);
> >>> +
> >>> + cs[j] = 0x24 << 23 | 1; /* SRM */
> >>> + if (has_64bit_reloc)
> >>> + cs[j]++;
> >>> + j++;
> >>> + cs[j++] = RCS_TIMESTAMP;
> >>> + cs[j++] = offset;
> >>> + if (has_64bit_reloc)
> >>> + cs[j++] = offset >> 32;
> >>> + cs[j++] = MI_BATCH_BUFFER_END;
> >>> +
> >>> + munmap(cs, 4096);
> >>> +
> >>> + gem_execbuf(i915, &execbuf);
> >>> + gem_close(i915, obj[1].handle);
> >>> + close(execbuf.rsvd2);
> >>> + }
> >>> + close(timeline);
> >>> + gem_sync(i915, results.handle);
> >>> +
> >>> + map = gem_mmap__cpu(i915, results.handle, 0, 4096, PROT_READ);
> >>> + gem_set_domain(i915, results.handle, I915_GEM_DOMAIN_CPU, 0);
> >>> + gem_close(i915, results.handle);
> >>> +
> >>> + last = map[0];
> >>> + for (int i = 1; i < num_engines; i++) {
> >>> + igt_assert_f((map[i] - last) > 0,
> >>> + "Engine instance [%d] executed too early: this:%x, last:%x\n",
> >>> + i, map[i], last);
> >>> + last = map[i];
> >>> + }
> >>
> >> Hm.. aren't two sw fences (two seqnos) just a needless complication -
> >> since the execution order in the single timeline is controlled by
> >> submission order. The statement is true only when compounded with the
> >> fact that you signal both fences at the same time. I am thinking that if
> >> it wasn't a single timeline context what would happen. Fences would be
> >> signaled in order, but execution does not have to happen in order. That
> >> it does is a property of single timeline and not fence ordering. So two
> >> input fences with two seqnos is misleading. Single plug would do I think
> >
> > But that would not detect the case when it was multiple timelines...
> >
> >> Or you are thinking to nudge the driver to do the right thing? But in
> >> that case I think you'd need to manually advance the first seqno (2nd
> >> batch) first and wait a bit to check it hasn't been execute. Then signal
> >> the second seqno (first batch) and run the above check to see they have
> >> been executed in order.
> >
> > The challenge is that we detect if the driver uses 2 timelines instead
> > of one. So that is what we setup to detect.
>
> With a single seqno advance what determines the order of signal delivery
> on blocked fences? Is it defined in the dma-fence contract it happens in
> order? If it is, then is it defined that would map to in order
> submission in i915 (if the contexts/timelines were separate)? (Might not
> I am thinking, scheduler can decide whatever it wants.)

We don't emit signals in order. Mostly we do, but not strictly.

> So I don't see a problem with being more explicit in this test and doing
> a step by step timeline advance so it is completely under test's control
> what's happening. And it would AFAICS detect the two timelines because
> it would expect first timeline advance must not result in request execution.

I don't see the problem with the test, it does what I need it to.
-Chris