[Intel-gfx] [PATCH] drm/i915/selftests: Let other struct_mutex users have their gpu time
Chris Wilson
chris at chris-wilson.co.uk
Tue Jul 3 08:30:15 UTC 2018
live_gtt is a very slow test to run, simply because it tries to allocate
and use as much as the 48b address space as possibly can and in the
process will try to own all of the system memory. This leads to resource
exhaustion and CPU starvation; the latter impacts us when the NMI
watchdog declares a task hung due to a mutex contention with ourselves.
This we can prevent by releasing the struct_mutex around cond_resched(),
to allow e.g. the i915_gem_free_objects_work to acquire the mutex and
cleanup.
References: https://bugs.freedesktop.org/show_bug.cgi?id=107094
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
drivers/gpu/drm/i915/selftests/i915_gem_gtt.c | 58 ++++++++++++++-----
1 file changed, 45 insertions(+), 13 deletions(-)
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
index a28ee0cc6a63..789add200720 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
@@ -32,6 +32,14 @@
#include "mock_drm.h"
#include "mock_gem_device.h"
+static void schedule_locked(struct drm_i915_private *i915)
+{
+ /* Let anyone else who wants the context take it */
+ mutex_unlock(&i915->drm.struct_mutex);
+ cond_resched();
+ mutex_lock(&i915->drm.struct_mutex);
+}
+
static void fake_free_pages(struct drm_i915_gem_object *obj,
struct sg_table *pages)
{
@@ -132,18 +140,18 @@ fake_dma_object(struct drm_i915_private *i915, u64 size)
static int igt_ppgtt_alloc(void *arg)
{
- struct drm_i915_private *dev_priv = arg;
+ struct drm_i915_private *i915 = arg;
struct i915_hw_ppgtt *ppgtt;
u64 size, last;
int err = 0;
/* Allocate a ppggt and try to fill the entire range */
- if (!USES_PPGTT(dev_priv))
+ if (!USES_PPGTT(i915))
return 0;
- mutex_lock(&dev_priv->drm.struct_mutex);
- ppgtt = __hw_ppgtt_create(dev_priv);
+ mutex_lock(&i915->drm.struct_mutex);
+ ppgtt = __hw_ppgtt_create(i915);
if (IS_ERR(ppgtt)) {
err = PTR_ERR(ppgtt);
goto err_unlock;
@@ -169,6 +177,8 @@ static int igt_ppgtt_alloc(void *arg)
ppgtt->vm.clear_range(&ppgtt->vm, 0, size);
}
+ schedule_locked(i915);
+
/* Check we can incrementally allocate the entire range */
for (last = 0, size = 4096;
size <= ppgtt->vm.total;
@@ -189,7 +199,7 @@ static int igt_ppgtt_alloc(void *arg)
ppgtt->vm.cleanup(&ppgtt->vm);
kfree(ppgtt);
err_unlock:
- mutex_unlock(&dev_priv->drm.struct_mutex);
+ mutex_unlock(&i915->drm.struct_mutex);
return err;
}
@@ -291,6 +301,8 @@ static int lowlevel_hole(struct drm_i915_private *i915,
i915_gem_object_put(obj);
kfree(order);
+
+ schedule_locked(i915);
}
return 0;
@@ -519,6 +531,7 @@ static int fill_hole(struct drm_i915_private *i915,
}
close_object_list(&objects, vm);
+ schedule_locked(i915);
}
return 0;
@@ -605,6 +618,8 @@ static int walk_hole(struct drm_i915_private *i915,
i915_gem_object_put(obj);
if (err)
return err;
+
+ schedule_locked(i915);
}
return 0;
@@ -676,6 +691,8 @@ static int pot_hole(struct drm_i915_private *i915,
err = -EINTR;
goto err;
}
+
+ schedule_locked(i915);
}
err:
@@ -789,6 +806,8 @@ static int drunk_hole(struct drm_i915_private *i915,
kfree(order);
if (err)
return err;
+
+ schedule_locked(i915);
}
return 0;
@@ -854,6 +873,8 @@ static int __shrink_hole(struct drm_i915_private *i915,
err = -EINTR;
break;
}
+
+ schedule_locked(i915);
}
close_object_list(&objects, vm);
@@ -949,6 +970,7 @@ static int shrink_boom(struct drm_i915_private *i915,
i915_gem_object_put(explode);
memset(&vm->fault_attr, 0, sizeof(vm->fault_attr));
+ schedule_locked(i915);
}
return 0;
@@ -961,7 +983,7 @@ static int shrink_boom(struct drm_i915_private *i915,
return err;
}
-static int exercise_ppgtt(struct drm_i915_private *dev_priv,
+static int exercise_ppgtt(struct drm_i915_private *i915,
int (*func)(struct drm_i915_private *i915,
struct i915_address_space *vm,
u64 hole_start, u64 hole_end,
@@ -972,15 +994,15 @@ static int exercise_ppgtt(struct drm_i915_private *dev_priv,
IGT_TIMEOUT(end_time);
int err;
- if (!USES_FULL_PPGTT(dev_priv))
+ if (!USES_FULL_PPGTT(i915))
return 0;
- file = mock_file(dev_priv);
+ file = mock_file(i915);
if (IS_ERR(file))
return PTR_ERR(file);
- mutex_lock(&dev_priv->drm.struct_mutex);
- ppgtt = i915_ppgtt_create(dev_priv, file->driver_priv, "mock");
+ mutex_lock(&i915->drm.struct_mutex);
+ ppgtt = i915_ppgtt_create(i915, file->driver_priv, "mock");
if (IS_ERR(ppgtt)) {
err = PTR_ERR(ppgtt);
goto out_unlock;
@@ -988,14 +1010,14 @@ static int exercise_ppgtt(struct drm_i915_private *dev_priv,
GEM_BUG_ON(offset_in_page(ppgtt->vm.total));
GEM_BUG_ON(ppgtt->vm.closed);
- err = func(dev_priv, &ppgtt->vm, 0, ppgtt->vm.total, end_time);
+ err = func(i915, &ppgtt->vm, 0, ppgtt->vm.total, end_time);
i915_ppgtt_close(&ppgtt->vm);
i915_ppgtt_put(ppgtt);
out_unlock:
- mutex_unlock(&dev_priv->drm.struct_mutex);
+ mutex_unlock(&i915->drm.struct_mutex);
- mock_file_free(dev_priv, file);
+ mock_file_free(i915, file);
return err;
}
@@ -1315,6 +1337,8 @@ static int igt_gtt_reserve(void *arg)
}
}
+ schedule_locked(i915);
+
/* Now we start forcing evictions */
for (total = I915_GTT_PAGE_SIZE;
total + 2*I915_GTT_PAGE_SIZE <= i915->ggtt.vm.total;
@@ -1364,6 +1388,8 @@ static int igt_gtt_reserve(void *arg)
}
}
+ schedule_locked(i915);
+
/* And then try at random */
list_for_each_entry_safe(obj, on, &objects, st_link) {
struct i915_vma *vma;
@@ -1517,6 +1543,8 @@ static int igt_gtt_insert(void *arg)
GEM_BUG_ON(!drm_mm_node_allocated(&vma->node));
}
+ schedule_locked(i915);
+
list_for_each_entry(obj, &objects, st_link) {
struct i915_vma *vma;
@@ -1535,6 +1563,8 @@ static int igt_gtt_insert(void *arg)
__i915_vma_unpin(vma);
}
+ schedule_locked(i915);
+
/* If we then reinsert, we should find the same hole */
list_for_each_entry_safe(obj, on, &objects, st_link) {
struct i915_vma *vma;
@@ -1575,6 +1605,8 @@ static int igt_gtt_insert(void *arg)
}
}
+ schedule_locked(i915);
+
/* And then force evictions */
for (total = 0;
total + 2*I915_GTT_PAGE_SIZE <= i915->ggtt.vm.total;
--
2.18.0
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