Commit aae4a3d8 authored by Chris Wilson's avatar Chris Wilson

drm/i915: Use fault-injection to force the shrinker to run in live GTT tests

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=99295Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarMatthew Auld <matthew.auld@intel.com>
parent 4a6f13fc
...@@ -65,6 +65,7 @@ config DRM_I915_SELFTEST ...@@ -65,6 +65,7 @@ config DRM_I915_SELFTEST
bool "Enable selftests upon driver load" bool "Enable selftests upon driver load"
depends on DRM_I915 depends on DRM_I915
default n default n
select FAULT_INJECTION
select PRIME_NUMBERS select PRIME_NUMBERS
help help
Choose this option to allow the driver to perform selftests upon Choose this option to allow the driver to perform selftests upon
......
...@@ -2485,6 +2485,8 @@ struct drm_i915_private { ...@@ -2485,6 +2485,8 @@ struct drm_i915_private {
/* Used to save the pipe-to-encoder mapping for audio */ /* Used to save the pipe-to-encoder mapping for audio */
struct intel_encoder *av_enc_map[I915_MAX_PIPES]; struct intel_encoder *av_enc_map[I915_MAX_PIPES];
I915_SELFTEST_DECLARE(struct fault_attr vm_fault);
/* /*
* NOTE: This is the dri1/ums dungeon, don't add stuff here. Your patch * NOTE: This is the dri1/ums dungeon, don't add stuff here. Your patch
* will be rejected. Instead look for a better place. * will be rejected. Instead look for a better place.
......
...@@ -23,6 +23,9 @@ ...@@ -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/log2.h>
#include <linux/random.h> #include <linux/random.h>
#include <linux/seq_file.h> #include <linux/seq_file.h>
...@@ -345,6 +348,9 @@ static int __setup_page_dma(struct drm_i915_private *dev_priv, ...@@ -345,6 +348,9 @@ static int __setup_page_dma(struct drm_i915_private *dev_priv,
{ {
struct device *kdev = &dev_priv->drm.pdev->dev; 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); p->page = alloc_page(flags);
if (!p->page) if (!p->page)
return -ENOMEM; return -ENOMEM;
......
...@@ -36,6 +36,8 @@ struct i915_selftest { ...@@ -36,6 +36,8 @@ struct i915_selftest {
}; };
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
#include <linux/fault-inject.h>
extern struct i915_selftest i915_selftest; extern struct i915_selftest i915_selftest;
int i915_mock_selftests(void); int i915_mock_selftests(void);
......
...@@ -271,11 +271,14 @@ static void close_object_list(struct list_head *objects, ...@@ -271,11 +271,14 @@ static void close_object_list(struct list_head *objects,
struct i915_address_space *vm) struct i915_address_space *vm)
{ {
struct drm_i915_gem_object *obj, *on; struct drm_i915_gem_object *obj, *on;
int ignored;
list_for_each_entry_safe(obj, on, objects, st_link) { list_for_each_entry_safe(obj, on, objects, st_link) {
struct i915_vma *vma; struct i915_vma *vma;
vma = i915_vma_instance(obj, vm, NULL); 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 */ /* Only ppgtt vma may be closed before the object is freed */
if (!IS_ERR(vma) && !i915_vma_is_ggtt(vma)) if (!IS_ERR(vma) && !i915_vma_is_ggtt(vma))
i915_vma_close(vma); i915_vma_close(vma);
...@@ -677,6 +680,95 @@ static int drunk_hole(struct drm_i915_private *i915, ...@@ -677,6 +680,95 @@ static int drunk_hole(struct drm_i915_private *i915,
return 0; 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, static int exercise_ppgtt(struct drm_i915_private *dev_priv,
int (*func)(struct drm_i915_private *i915, int (*func)(struct drm_i915_private *i915,
struct i915_address_space *vm, struct i915_address_space *vm,
...@@ -735,6 +827,11 @@ static int igt_ppgtt_lowlevel(void *arg) ...@@ -735,6 +827,11 @@ static int igt_ppgtt_lowlevel(void *arg)
return exercise_ppgtt(arg, lowlevel_hole); 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) 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); 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) ...@@ -812,6 +909,7 @@ int i915_gem_gtt_live_selftests(struct drm_i915_private *i915)
SUBTEST(igt_ppgtt_drunk), SUBTEST(igt_ppgtt_drunk),
SUBTEST(igt_ppgtt_walk), SUBTEST(igt_ppgtt_walk),
SUBTEST(igt_ppgtt_fill), SUBTEST(igt_ppgtt_fill),
SUBTEST(igt_ppgtt_shrink),
SUBTEST(igt_ggtt_lowlevel), SUBTEST(igt_ggtt_lowlevel),
SUBTEST(igt_ggtt_drunk), SUBTEST(igt_ggtt_drunk),
SUBTEST(igt_ggtt_walk), SUBTEST(igt_ggtt_walk),
......
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