drm: kselftest for drm_mm and eviction
authorChris Wilson <chris@chris-wilson.co.uk>
Thu, 22 Dec 2016 08:36:17 +0000 (08:36 +0000)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Tue, 27 Dec 2016 11:37:55 +0000 (12:37 +0100)
Check that we add arbitrary blocks to the eviction scanner in order to
find the first minimal hole that matches our request.

v2: Refactor out some common eviction code for later

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161222083641.2691-15-chris@chris-wilson.co.uk
drivers/gpu/drm/selftests/drm_mm_selftests.h
drivers/gpu/drm/selftests/test-drm_mm.c

index a7a3763f8b2053c058da89941571121423ce50ba..a31b4458c7ebeb619346fe05c28cc135cc052ae0 100644 (file)
@@ -15,3 +15,4 @@ selftest(insert_range, igt_insert_range)
 selftest(align, igt_align)
 selftest(align32, igt_align32)
 selftest(align64, igt_align64)
+selftest(evict, igt_evict)
index 53ba268e07d96a9b872a14bcf13b58e1c5918968..065e2c72845bd69dc1d02b41b9ff78f49db4ddb8 100644 (file)
@@ -36,6 +36,10 @@ static const struct insert_mode {
        [TOPDOWN] = { "top-down", DRM_MM_SEARCH_BELOW, DRM_MM_CREATE_TOP },
        [BEST] = { "best", DRM_MM_SEARCH_BEST, DRM_MM_CREATE_DEFAULT },
        {}
+}, evict_modes[] = {
+       { "default", DRM_MM_SEARCH_DEFAULT, DRM_MM_CREATE_DEFAULT },
+       { "top-down", DRM_MM_SEARCH_BELOW, DRM_MM_CREATE_TOP },
+       {}
 };
 
 static int igt_sanitycheck(void *ignored)
@@ -1110,6 +1114,339 @@ static int igt_align64(void *ignored)
        return igt_align_pot(64);
 }
 
+static void show_scan(const struct drm_mm *scan)
+{
+       pr_info("scan: hit [%llx, %llx], size=%lld, align=%d, color=%ld\n",
+               scan->scan_hit_start, scan->scan_hit_end,
+               scan->scan_size, scan->scan_alignment, scan->scan_color);
+}
+
+static void show_holes(const struct drm_mm *mm, int count)
+{
+       u64 hole_start, hole_end;
+       struct drm_mm_node *hole;
+
+       drm_mm_for_each_hole(hole, mm, hole_start, hole_end) {
+               struct drm_mm_node *next = list_next_entry(hole, node_list);
+               const char *node1 = NULL, *node2 = NULL;
+
+               if (hole->allocated)
+                       node1 = kasprintf(GFP_KERNEL,
+                                         "[%llx + %lld, color=%ld], ",
+                                         hole->start, hole->size, hole->color);
+
+               if (next->allocated)
+                       node2 = kasprintf(GFP_KERNEL,
+                                         ", [%llx + %lld, color=%ld]",
+                                         next->start, next->size, next->color);
+
+               pr_info("%sHole [%llx - %llx, size %lld]%s\n",
+                       node1,
+                       hole_start, hole_end, hole_end - hole_start,
+                       node2);
+
+               kfree(node2);
+               kfree(node1);
+
+               if (!--count)
+                       break;
+       }
+}
+
+struct evict_node {
+       struct drm_mm_node node;
+       struct list_head link;
+};
+
+static bool evict_nodes(struct drm_mm *mm,
+                       struct evict_node *nodes,
+                       unsigned int *order,
+                       unsigned int count,
+                       struct list_head *evict_list)
+{
+       struct evict_node *e, *en;
+       unsigned int i;
+
+       for (i = 0; i < count; i++) {
+               e = &nodes[order ? order[i] : i];
+               list_add(&e->link, evict_list);
+               if (drm_mm_scan_add_block(&e->node))
+                       break;
+       }
+       list_for_each_entry_safe(e, en, evict_list, link) {
+               if (!drm_mm_scan_remove_block(&e->node))
+                       list_del(&e->link);
+       }
+       if (list_empty(evict_list)) {
+               pr_err("Failed to find eviction: size=%lld [avail=%d], align=%d (color=%lu)\n",
+                      mm->scan_size, count,
+                      mm->scan_alignment,
+                      mm->scan_color);
+               return false;
+       }
+
+       list_for_each_entry(e, evict_list, link)
+               drm_mm_remove_node(&e->node);
+
+       return true;
+}
+
+static bool evict_nothing(struct drm_mm *mm,
+                         unsigned int total_size,
+                         struct evict_node *nodes)
+{
+       LIST_HEAD(evict_list);
+       struct evict_node *e;
+       struct drm_mm_node *node;
+       unsigned int n;
+
+       drm_mm_init_scan(mm, 1, 0, 0);
+       for (n = 0; n < total_size; n++) {
+               e = &nodes[n];
+               list_add(&e->link, &evict_list);
+               drm_mm_scan_add_block(&e->node);
+       }
+       list_for_each_entry(e, &evict_list, link)
+               drm_mm_scan_remove_block(&e->node);
+
+       for (n = 0; n < total_size; n++) {
+               e = &nodes[n];
+
+               if (!drm_mm_node_allocated(&e->node)) {
+                       pr_err("node[%d] no longer allocated!\n", n);
+                       return false;
+               }
+
+               e->link.next = NULL;
+       }
+
+       drm_mm_for_each_node(node, mm) {
+               e = container_of(node, typeof(*e), node);
+               e->link.next = &e->link;
+       }
+
+       for (n = 0; n < total_size; n++) {
+               e = &nodes[n];
+
+               if (!e->link.next) {
+                       pr_err("node[%d] no longer connected!\n", n);
+                       return false;
+               }
+       }
+
+       return assert_continuous(mm, nodes[0].node.size);
+}
+
+static bool evict_everything(struct drm_mm *mm,
+                            unsigned int total_size,
+                            struct evict_node *nodes)
+{
+       LIST_HEAD(evict_list);
+       struct evict_node *e;
+       unsigned int n;
+       int err;
+
+       drm_mm_init_scan(mm, total_size, 0, 0);
+       for (n = 0; n < total_size; n++) {
+               e = &nodes[n];
+               list_add(&e->link, &evict_list);
+               drm_mm_scan_add_block(&e->node);
+       }
+       list_for_each_entry(e, &evict_list, link) {
+               if (!drm_mm_scan_remove_block(&e->node)) {
+                       pr_err("Node %lld not marked for eviction!\n",
+                              e->node.start);
+                       list_del(&e->link);
+               }
+       }
+
+       list_for_each_entry(e, &evict_list, link)
+               drm_mm_remove_node(&e->node);
+
+       if (!assert_one_hole(mm, 0, total_size))
+               return false;
+
+       list_for_each_entry(e, &evict_list, link) {
+               err = drm_mm_reserve_node(mm, &e->node);
+               if (err) {
+                       pr_err("Failed to reinsert node after eviction: start=%llx\n",
+                              e->node.start);
+                       return false;
+               }
+       }
+
+       return assert_continuous(mm, nodes[0].node.size);
+}
+
+static int evict_something(struct drm_mm *mm,
+                          struct evict_node *nodes,
+                          unsigned int *order,
+                          unsigned int count,
+                          unsigned int size,
+                          unsigned int alignment,
+                          const struct insert_mode *mode)
+{
+       LIST_HEAD(evict_list);
+       struct evict_node *e;
+       struct drm_mm_node tmp;
+       int err;
+
+       drm_mm_init_scan(mm, size, alignment, 0);
+       if (!evict_nodes(mm,
+                        nodes, order, count,
+                        &evict_list))
+               return -EINVAL;
+
+       memset(&tmp, 0, sizeof(tmp));
+       err = drm_mm_insert_node_generic(mm, &tmp, size, alignment, 0,
+                                        mode->search_flags,
+                                        mode->create_flags);
+       if (err) {
+               pr_err("Failed to insert into eviction hole: size=%d, align=%d\n",
+                      size, alignment);
+               show_scan(mm);
+               show_holes(mm, 3);
+               return err;
+       }
+
+       if (!assert_node(&tmp, mm, size, alignment, 0) || tmp.hole_follows) {
+               pr_err("Inserted did not fill the eviction hole: size=%lld [%d], align=%d [rem=%lld], start=%llx, hole-follows?=%d\n",
+                      tmp.size, size,
+                      alignment, misalignment(&tmp, alignment),
+                      tmp.start, tmp.hole_follows);
+               err = -EINVAL;
+       }
+
+       drm_mm_remove_node(&tmp);
+       if (err)
+               return err;
+
+       list_for_each_entry(e, &evict_list, link) {
+               err = drm_mm_reserve_node(mm, &e->node);
+               if (err) {
+                       pr_err("Failed to reinsert node after eviction: start=%llx\n",
+                              e->node.start);
+                       return err;
+               }
+       }
+
+       if (!assert_continuous(mm, nodes[0].node.size)) {
+               pr_err("range is no longer continuous\n");
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int igt_evict(void *ignored)
+{
+       DRM_RND_STATE(prng, random_seed);
+       const unsigned int size = 8192;
+       const struct insert_mode *mode;
+       struct drm_mm mm;
+       struct evict_node *nodes;
+       struct drm_mm_node *node, *next;
+       unsigned int *order, n;
+       int ret, err;
+
+       /* Here we populate a full drm_mm and then try and insert a new node
+        * by evicting other nodes in a random order. The drm_mm_scan should
+        * pick the first matching hole it finds from the random list. We
+        * repeat that for different allocation strategies, alignments and
+        * sizes to try and stress the hole finder.
+        */
+
+       ret = -ENOMEM;
+       nodes = vzalloc(size * sizeof(*nodes));
+       if (!nodes)
+               goto err;
+
+       order = drm_random_order(size, &prng);
+       if (!order)
+               goto err_nodes;
+
+       ret = -EINVAL;
+       drm_mm_init(&mm, 0, size);
+       for (n = 0; n < size; n++) {
+               err = drm_mm_insert_node(&mm, &nodes[n].node, 1, 0,
+                                        DRM_MM_SEARCH_DEFAULT);
+               if (err) {
+                       pr_err("insert failed, step %d\n", n);
+                       ret = err;
+                       goto out;
+               }
+       }
+
+       /* First check that using the scanner doesn't break the mm */
+       if (!evict_nothing(&mm, size, nodes)) {
+               pr_err("evict_nothing() failed\n");
+               goto out;
+       }
+       if (!evict_everything(&mm, size, nodes)) {
+               pr_err("evict_everything() failed\n");
+               goto out;
+       }
+
+       for (mode = evict_modes; mode->name; mode++) {
+               for (n = 1; n <= size; n <<= 1) {
+                       drm_random_reorder(order, size, &prng);
+                       err = evict_something(&mm,
+                                             nodes, order, size,
+                                             n, 1,
+                                             mode);
+                       if (err) {
+                               pr_err("%s evict_something(size=%u) failed\n",
+                                      mode->name, n);
+                               ret = err;
+                               goto out;
+                       }
+               }
+
+               for (n = 1; n < size; n <<= 1) {
+                       drm_random_reorder(order, size, &prng);
+                       err = evict_something(&mm,
+                                             nodes, order, size,
+                                             size/2, n,
+                                             mode);
+                       if (err) {
+                               pr_err("%s evict_something(size=%u, alignment=%u) failed\n",
+                                      mode->name, size/2, n);
+                               ret = err;
+                               goto out;
+                       }
+               }
+
+               for_each_prime_number_from(n, 1, min(size, max_prime)) {
+                       unsigned int nsize = (size - n + 1) / 2;
+
+                       DRM_MM_BUG_ON(!nsize);
+
+                       drm_random_reorder(order, size, &prng);
+                       err = evict_something(&mm,
+                                             nodes, order, size,
+                                             nsize, n,
+                                             mode);
+                       if (err) {
+                               pr_err("%s evict_something(size=%u, alignment=%u) failed\n",
+                                      mode->name, nsize, n);
+                               ret = err;
+                               goto out;
+                       }
+               }
+       }
+
+       ret = 0;
+out:
+       drm_mm_for_each_node_safe(node, next, &mm)
+               drm_mm_remove_node(node);
+       drm_mm_takedown(&mm);
+       kfree(order);
+err_nodes:
+       vfree(nodes);
+err:
+       return ret;
+}
+
 #include "drm_selftest.c"
 
 static int __init test_drm_mm_init(void)