It is possible whilst allocating the page-directory tree for a ppgtt bind that the shrinker may run and reap unused parts of the tree. If the shrinker happens to remove a chunk of the tree that the allocate_va_range has already processed, we may then try to insert into the dangling tree. This test uses the fault-injection framework to force the shrinker to be invoked before we allocate new pages, i.e. new chunks of the PD tree. References: https://bugs.freedesktop.org/show_bug.cgi?id=99295 Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Reviewed-by: Matthew Auld <matthew.auld@xxxxxxxxx> --- drivers/gpu/drm/i915/Kconfig.debug | 1 + drivers/gpu/drm/i915/i915_drv.h | 2 + drivers/gpu/drm/i915/i915_gem_gtt.c | 6 ++ drivers/gpu/drm/i915/i915_selftest.h | 2 + drivers/gpu/drm/i915/selftests/i915_gem_gtt.c | 98 +++++++++++++++++++++++++++ 5 files changed, 109 insertions(+) diff --git a/drivers/gpu/drm/i915/Kconfig.debug b/drivers/gpu/drm/i915/Kconfig.debug index a4d8cfd77c3c..68ff072f8b76 100644 --- a/drivers/gpu/drm/i915/Kconfig.debug +++ b/drivers/gpu/drm/i915/Kconfig.debug @@ -65,6 +65,7 @@ config DRM_I915_SELFTEST bool "Enable selftests upon driver load" depends on DRM_I915 default n + select FAULT_INJECTION select PRIME_NUMBERS help Choose this option to allow the driver to perform selftests upon diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index b5f150b0870d..5b824e5b465f 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2491,6 +2491,8 @@ struct drm_i915_private { int irq; } lpe_audio; + I915_SELFTEST_DECLARE(struct fault_attr vm_fault); + /* * NOTE: This is the dri1/ums dungeon, don't add stuff here. Your patch * will be rejected. Instead look for a better place. diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index 9daea3cd9cdc..f8ac69380a0f 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -23,6 +23,9 @@ * */ +#include <linux/slab.h> /* fault-inject.h is not standalone! */ + +#include <linux/fault-inject.h> #include <linux/log2.h> #include <linux/random.h> #include <linux/seq_file.h> @@ -345,6 +348,9 @@ static int __setup_page_dma(struct drm_i915_private *dev_priv, { struct device *kdev = &dev_priv->drm.pdev->dev; + if (I915_SELFTEST_ONLY(should_fail(&dev_priv->vm_fault, 1))) + i915_gem_shrink_all(dev_priv); + p->page = alloc_page(flags); if (!p->page) return -ENOMEM; diff --git a/drivers/gpu/drm/i915/i915_selftest.h b/drivers/gpu/drm/i915/i915_selftest.h index e43777b72211..9d7d86f1733d 100644 --- a/drivers/gpu/drm/i915/i915_selftest.h +++ b/drivers/gpu/drm/i915/i915_selftest.h @@ -36,6 +36,8 @@ struct i915_selftest { }; #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) +#include <linux/fault-inject.h> + extern struct i915_selftest i915_selftest; int i915_mock_selftests(void); diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c index d0ec74671ef8..2e571bbe98ae 100644 --- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c @@ -271,11 +271,14 @@ static void close_object_list(struct list_head *objects, struct i915_address_space *vm) { struct drm_i915_gem_object *obj, *on; + int ignored; list_for_each_entry_safe(obj, on, objects, st_link) { struct i915_vma *vma; vma = i915_vma_instance(obj, vm, NULL); + if (!IS_ERR(vma)) + ignored = i915_vma_unbind(vma); /* Only ppgtt vma may be closed before the object is freed */ if (!IS_ERR(vma) && !i915_vma_is_ggtt(vma)) i915_vma_close(vma); @@ -677,6 +680,95 @@ static int drunk_hole(struct drm_i915_private *i915, return 0; } +static int __shrink_hole(struct drm_i915_private *i915, + struct i915_address_space *vm, + u64 hole_start, u64 hole_end, + unsigned long end_time) +{ + struct drm_i915_gem_object *obj; + unsigned long flags = PIN_OFFSET_FIXED | PIN_USER; + unsigned int order = 12; + LIST_HEAD(objects); + int err = 0; + u64 addr; + + /* Keep creating larger objects until one cannot fit into the hole */ + for (addr = hole_start; addr < hole_end; ) { + struct i915_vma *vma; + u64 size = BIT_ULL(order++); + + size = min(size, hole_end - addr); + obj = fake_dma_object(i915, size); + if (IS_ERR(obj)) { + err = PTR_ERR(obj); + break; + } + + list_add(&obj->st_link, &objects); + + vma = i915_vma_instance(obj, vm, NULL); + if (IS_ERR(vma)) { + err = PTR_ERR(vma); + break; + } + + GEM_BUG_ON(vma->size != size); + + err = i915_vma_pin(vma, 0, 0, addr | flags); + if (err) { + pr_err("%s failed to pin object at %llx + %llx in hole [%llx - %llx], with err=%d\n", + __func__, addr, size, hole_start, hole_end, err); + break; + } + + if (!drm_mm_node_allocated(&vma->node) || + i915_vma_misplaced(vma, 0, 0, addr | flags)) { + pr_err("%s incorrect at %llx + %llx\n", + __func__, addr, size); + i915_vma_unpin(vma); + err = i915_vma_unbind(vma); + err = -EINVAL; + break; + } + + i915_vma_unpin(vma); + addr += size; + + if (igt_timeout(end_time, + "%s timed out at ofset %llx [%llx - %llx]\n", + __func__, addr, hole_start, hole_end)) { + err = -EINTR; + break; + } + } + + close_object_list(&objects, vm); + return err; +} + +static int shrink_hole(struct drm_i915_private *i915, + struct i915_address_space *vm, + u64 hole_start, u64 hole_end, + unsigned long end_time) +{ + unsigned long prime; + int err; + + i915->vm_fault.probability = 999; + atomic_set(&i915->vm_fault.times, -1); + + for_each_prime_number_from(prime, 0, ULONG_MAX - 1) { + i915->vm_fault.interval = prime; + err = __shrink_hole(i915, vm, hole_start, hole_end, end_time); + if (err) + break; + } + + memset(&i915->vm_fault, 0, sizeof(i915->vm_fault)); + + return err; +} + static int exercise_ppgtt(struct drm_i915_private *dev_priv, int (*func)(struct drm_i915_private *i915, struct i915_address_space *vm, @@ -735,6 +827,11 @@ static int igt_ppgtt_lowlevel(void *arg) return exercise_ppgtt(arg, lowlevel_hole); } +static int igt_ppgtt_shrink(void *arg) +{ + return exercise_ppgtt(arg, shrink_hole); +} + static int sort_holes(void *priv, struct list_head *A, struct list_head *B) { struct drm_mm_node *a = list_entry(A, typeof(*a), hole_stack); @@ -812,6 +909,7 @@ int i915_gem_gtt_live_selftests(struct drm_i915_private *i915) SUBTEST(igt_ppgtt_drunk), SUBTEST(igt_ppgtt_walk), SUBTEST(igt_ppgtt_fill), + SUBTEST(igt_ppgtt_shrink), SUBTEST(igt_ggtt_lowlevel), SUBTEST(igt_ggtt_drunk), SUBTEST(igt_ggtt_walk), -- 2.11.0 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
