Quoting Matthew Auld (2018-01-31 19:14:53) > Try to catch a bug we've seen in the wild where the shrinker purges the > pd/pdp from under us while allocating our paging structures. > > References: https://bugs.freedesktop.org/show_bug.cgi?id=104773 > Signed-off-by: Matthew Auld <matthew.auld@xxxxxxxxx> > Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > --- > drivers/gpu/drm/i915/selftests/i915_gem_gtt.c | 84 +++++++++++++++++++++++++++ > 1 file changed, 84 insertions(+) > > diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c > index bb7cf998fc65..a40a2a7514fd 100644 > --- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c > +++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c > @@ -885,6 +885,84 @@ static int shrink_hole(struct drm_i915_private *i915, > return err; > } > > +static int shrink_boom(struct drm_i915_private *i915, > + struct i915_address_space *vm, > + u64 hole_start, u64 hole_end, > + unsigned long end_time) > +{ > + unsigned int sizes[] = {SZ_2M, SZ_1G}; > + struct drm_i915_gem_object *purge; > + struct drm_i915_gem_object *explode; > + struct i915_vma *vma; > + unsigned int flags = PIN_USER | PIN_OFFSET_FIXED; > + int err; > + int i; > + > + /* > + * Catch the case which shrink_hole seems to miss. The setup here > + * requires invoking the shrinker as we do the alloc_pt/alloc_pd, while > + * ensuring that all vma assiocated with the respective pd/pdp are > + * unpinned at the time. > + */ Question for everyone: can we see more holes in shrink_hole? > + > + for (i = 0; i < ARRAY_SIZE(sizes); ++i) { > + unsigned int size = sizes[i]; > + > + purge = fake_dma_object(i915, size); > + if (IS_ERR(purge)) > + return PTR_ERR(purge); > + > + vma = i915_vma_instance(purge, vm, NULL); > + if (IS_ERR(vma)) { > + err = PTR_ERR(vma); > + goto err_purge; > + } > + > + err = i915_vma_pin(vma, 0, 0, flags); > + if (err) > + goto err_purge; > + > + /* Should now be ripe for purging */ > + i915_vma_unpin(vma); > + > + explode = fake_dma_object(i915, size); > + if (IS_ERR(explode)) { > + err = PTR_ERR(purge); > + goto err_purge; > + } > + > + vm->fault_attr.probability = 100; > + vm->fault_attr.interval = 1; > + atomic_set(&vm->fault_attr.times, -1); > + > + vma = i915_vma_instance(explode, vm, NULL); > + if (IS_ERR(vma)) { > + err = PTR_ERR(vma); > + goto err_explode; > + } > + > + err = i915_vma_pin(vma, 0, 0, flags | size); > + if (err) > + goto err_explode; > + > + i915_vma_unpin(vma); > + > + i915_gem_object_put(purge); > + i915_gem_object_put(explode); > + > + memset(&vm->fault_attr, 0, sizeof(vm->fault_attr)); > + } > + > + return 0; > + > +err_explode: > + i915_gem_object_put(explode); > +err_purge: > + i915_gem_object_put(purge); > + > + return err; > +} As this demonstrates a shrinker bug we missed in the test intended to find all shrinker bugs, Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Just worrying about how deep the iceberg goes. (Though more about catching tomorrow's bug as we should have this one fixed pretty shortly.) -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
