[Intel-gfx] [PATCH i-g-t] tests/gem_ppgtt: Check for vm leaks with flink and ppgtt

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Using imported objects should not leak i915 vmas (and vms).

In practice this simulates Xorg importing fbcon and leaking (or not) one vma
per Xorg startup cycle.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
---
 tests/gem_ppgtt.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)

diff --git a/tests/gem_ppgtt.c b/tests/gem_ppgtt.c
index 5bf773c..9b5b3ee 100644
--- a/tests/gem_ppgtt.c
+++ b/tests/gem_ppgtt.c
@@ -200,6 +200,103 @@ static void surfaces_check(dri_bo **bo, int count, uint32_t expected)
 	}
 }
 
+static void flink_and_contexts(void)
+{
+	drm_intel_bufmgr *bufmgr;
+	int fd, fd2;
+	dri_bo *bo;
+	uint32_t flink_name;
+	unsigned int max_line = 0, num_lines = 0, cnt = 0;
+	int ret;
+
+	/*
+	 * Export a bo via flink and access it from a child process via a
+	 * different ppggtt context. Make sure when child exists that the vma
+	 * (and hence the vm), associated with its ppgtt context, is torn down.
+	 */
+
+	fd = drm_open_any();
+
+	bufmgr = drm_intel_bufmgr_gem_init(fd, 4096);
+	igt_assert(bufmgr);
+
+	bo = create_bo(bufmgr, 0);
+	igt_assert(bo);
+
+	ret = drm_intel_bo_flink(bo, &flink_name);
+	igt_assert(ret == 0);
+
+	igt_fork(child, 20) {
+		int devid;
+		drm_intel_bufmgr *bufmgr;
+		int fd;
+		dri_bo *bo, *import;
+		struct intel_batchbuffer *batch;
+
+		fd = drm_open_any();
+		devid = intel_get_drm_devid(fd);
+
+		bufmgr = drm_intel_bufmgr_gem_init(fd, 4096);
+		igt_assert(bufmgr);
+
+		bo = create_bo(bufmgr, 0);
+		import = drm_intel_bo_gem_create_from_name(bufmgr,
+							   "flink_and_contexts",
+							   flink_name);
+		igt_assert(bo && import);
+
+		batch = intel_batchbuffer_alloc(bufmgr, devid);
+		igt_assert(batch);
+
+		intel_copy_bo(batch, bo, import, SIZE);
+
+		intel_batchbuffer_free(batch);
+
+		dri_bo_unreference(import);
+		dri_bo_unreference(bo);
+
+		drm_intel_bufmgr_destroy(bufmgr);
+		close(fd);
+
+		exit(0);
+	}
+
+	igt_waitchildren();
+
+	/*
+	 * Count the longest line in the file which lists the vmas per object.
+	 * This might be a bit fragile so maybe there is a better way.
+	 */
+	fd2 = open("/sys/kernel/debug/dri/0/i915_gem_gtt", O_RDONLY);
+	igt_assert(fd2 >= 0);
+
+	do {
+		char ch;
+
+		ret = read(fd2, &ch, 1);
+		if (ret == 0)
+			break;
+		igt_assert(ret == 1);
+		if (ch == '\n') {
+			if (cnt > max_line)
+				max_line = cnt;
+			num_lines++;
+			cnt = 0;
+		} else {
+			cnt++;
+		}
+	} while (true);
+
+	close(fd2);
+
+	dri_bo_unreference(bo);
+	drm_intel_bufmgr_destroy(bufmgr);
+	close(fd);
+
+	igt_assert(num_lines >= 1);
+	igt_assert(max_line < 1000);
+}
+
 #define N_CHILD 8
 int main(int argc, char **argv)
 {
@@ -229,5 +326,8 @@ int main(int argc, char **argv)
 		surfaces_check(rcs, N_CHILD, 0x8000 / N_CHILD);
 	}
 
+	igt_subtest("flink-vs-ctx-vm-leak")
+		flink_and_contexts();
+
 	igt_exit();
 }
-- 
2.3.5