This patch introduces fragmentation in the address range
and measures time taken by 10k and 20k insertions. ig_frag()
will fail if the time taken by 20k insertions takes more than
4 times of 10k insertions as we know that insertions should at
most scale quadratically.
v2:
introduce fragmentation by freeing every other node.
only test bottom-up and top-down for now.
Signed-off-by: Nirmoy Das <nirmoy.das@xxxxxxx>
---
drivers/gpu/drm/selftests/drm_mm_selftests.h | 1 +
drivers/gpu/drm/selftests/test-drm_mm.c | 124
+++++++++++++++++++
2 files changed, 125 insertions(+)
diff --git a/drivers/gpu/drm/selftests/drm_mm_selftests.h
b/drivers/gpu/drm/selftests/drm_mm_selftests.h
index 6b943ea1c57d..8c87c964176b 100644
--- a/drivers/gpu/drm/selftests/drm_mm_selftests.h
+++ b/drivers/gpu/drm/selftests/drm_mm_selftests.h
@@ -14,6 +14,7 @@ selftest(insert, igt_insert)
selftest(replace, igt_replace)
selftest(insert_range, igt_insert_range)
selftest(align, igt_align)
+selftest(frag, igt_frag)
selftest(align32, igt_align32)
selftest(align64, igt_align64)
selftest(evict, igt_evict)
diff --git a/drivers/gpu/drm/selftests/test-drm_mm.c
b/drivers/gpu/drm/selftests/test-drm_mm.c
index 9aabe82dcd3a..34231baacd87 100644
--- a/drivers/gpu/drm/selftests/test-drm_mm.c
+++ b/drivers/gpu/drm/selftests/test-drm_mm.c
@@ -10,6 +10,7 @@
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/vmalloc.h>
+#include <linux/ktime.h>
#include <drm/drm_mm.h>
@@ -1033,6 +1034,129 @@ static int igt_insert_range(void *ignored)
return 0;
}
+static int prepare_igt_frag(struct drm_mm *mm,
+ struct drm_mm_node *nodes,
+ unsigned int num_insert,
+ const struct insert_mode *mode)
+{
+ unsigned int size = 4096;
+ unsigned int i;
+ u64 ret = -EINVAL;
+
+ for (i = 0; i < num_insert; i++) {
+ if (!expect_insert(mm, &nodes[i], size, 0, i,
+ mode) != 0) {
+ pr_err("%s insert failed\n", mode->name);
+ goto out;
+ }
+ }
+
+ /* introduce fragmentation by freeing every other node */
+ for (i = 0; i < num_insert; i++) {
+ if (i % 2 == 0)
+ drm_mm_remove_node(&nodes[i]);
+ }
+
+out:
+ return ret;
+
+}
+
+static u64 get_insert_time(struct drm_mm *mm,
+ unsigned int num_insert,
+ struct drm_mm_node *nodes,
+ const struct insert_mode *mode)
+{
+ unsigned int size = 8192;
+ ktime_t start;
+ unsigned int i;
+ u64 ret = -EINVAL;
+
+ start = ktime_get();
+ for (i = 0; i < num_insert; i++) {
+ if (!expect_insert(mm, &nodes[i], size, 0, i, mode) != 0) {
+ pr_err("%s insert failed\n", mode->name);
+ goto out;
+ }
+ }
+
+ ret = ktime_to_ns(ktime_sub(ktime_get(), start));
+
+out:
+ return ret;
+
+}
+
+static int igt_frag(void *ignored)
+{
+ struct drm_mm mm;
+ const struct insert_mode *mode;
+ struct drm_mm_node *nodes, *node, *next;
+ unsigned int insert_size = 10000;
+ unsigned int scale_factor = 4;
+ int ret = -EINVAL;
+
+ /* We need 4 * insert_size nodes to hold intermediate allocated
+ * drm_mm nodes.
+ * 1 times for prepare_igt_frag()
+ * 1 times for get_insert_time()
+ * 2 times for get_insert_time()
+ */
+ nodes = vzalloc(array_size(insert_size * 4, sizeof(*nodes)));
+ if (!nodes)
+ return -ENOMEM;
+
+ /* For BOTTOMUP and TOPDOWN, we first fragment the
+ * address space using prepare_igt_frag() and then try to verify
+ * that that insertions scale quadratically from 10k to 20k
insertions
+ */
+ drm_mm_init(&mm, 1, U64_MAX - 2);
+ for (mode = insert_modes; mode->name; mode++) {
+ u64 insert_time1, insert_time2;
+
+ if (mode->mode != DRM_MM_INSERT_LOW ||
+ mode->mode != DRM_MM_INSERT_HIGH)
+ continue;
