drm/i915/selftests: Fill all the drm_vma_manager holes

To test mmap_offset_exhaustion, we first have to fill the entire vma
manager leaving a single page. Don't assume that the vma manager is not
already fragment, and fill all the holes.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191111122706.28292-2-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
index cabf45b1403f1a5ece49c0a0fa4248929a1bcdfe..9f1a69027a04019f9e60c0c1d0f00c72b17ba726 100644 (file)
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
@@ -607,28 +607,49 @@ static int igt_mmap_offset_exhaustion(void *arg)
        struct drm_i915_private *i915 = arg;
        struct drm_mm *mm = &i915->drm.vma_offset_manager->vm_addr_space_mm;
        struct drm_i915_gem_object *obj;
-       struct drm_mm_node resv, *hole;
-       u64 hole_start, hole_end;
+       struct drm_mm_node *hole, *next;
        int loop, err;
 
        /* Disable background reaper */
        disable_retire_worker(i915);
        GEM_BUG_ON(!i915->gt.awake);
+       intel_gt_retire_requests(&i915->gt);
+       i915_gem_drain_freed_objects(i915);
 
        /* Trim the device mmap space to only a page */
-       memset(&resv, 0, sizeof(resv));
-       drm_mm_for_each_hole(hole, mm, hole_start, hole_end) {
-               resv.start = hole_start;
-               resv.size = hole_end - hole_start - 1; /* PAGE_SIZE units */
-               mmap_offset_lock(i915);
-               err = drm_mm_reserve_node(mm, &resv);
-               mmap_offset_unlock(i915);
+       mmap_offset_lock(i915);
+       loop = 1; /* PAGE_SIZE units */
+       list_for_each_entry_safe(hole, next, &mm->hole_stack, hole_stack) {
+               struct drm_mm_node *resv;
+
+               resv = kzalloc(sizeof(*resv), GFP_NOWAIT);
+               if (!resv) {
+                       err = -ENOMEM;
+                       goto out_park;
+               }
+
+               resv->start = drm_mm_hole_node_start(hole) + loop;
+               resv->size = hole->hole_size - loop;
+               resv->color = -1ul;
+               loop = 0;
+
+               if (!resv->size) {
+                       kfree(resv);
+                       continue;
+               }
+
+               pr_debug("Reserving hole [%llx + %llx]\n",
+                        resv->start, resv->size);
+
+               err = drm_mm_reserve_node(mm, resv);
                if (err) {
                        pr_err("Failed to trim VMA manager, err=%d\n", err);
+                       kfree(resv);
                        goto out_park;
                }
-               break;
        }
+       GEM_BUG_ON(!list_is_singular(&mm->hole_stack));
+       mmap_offset_unlock(i915);
 
        /* Just fits! */
        if (!assert_mmap_offset(i915, PAGE_SIZE, 0)) {
@@ -685,9 +706,15 @@ static int igt_mmap_offset_exhaustion(void *arg)
 
 out:
        mmap_offset_lock(i915);
-       drm_mm_remove_node(&resv);
-       mmap_offset_unlock(i915);
 out_park:
+       drm_mm_for_each_node_safe(hole, next, mm) {
+               if (hole->color != -1ul)
+                       continue;
+
+               drm_mm_remove_node(hole);
+               kfree(hole);
+       }
+       mmap_offset_unlock(i915);
        restore_retire_worker(i915);
        return err;
 err_obj: