3 files changed, 75 insertions, 14 deletions

diff --git a/lib/igt_core.c b/lib/igt_core.c
index 5092a3f0..06d8b037 100644
--- a/lib/igt_core.c
+++ b/lib/igt_core.c
@@ -1702,20 +1702,7 @@ void igt_child_done(pid_t pid)
 		test_children[i] = test_children[i + 1];
 }
 
-/**
- * igt_waitchildren:
- *
- * Wait for all children forked with igt_fork.
- *
- * The magic here is that exit codes from children will be correctly propagated
- * to the main thread, including the relevant exit code if a child thread failed.
- * Of course if multiple children failed with different exit codes the resulting
- * exit code will be non-deterministic.
- *
- * Note that igt_skip() will not be forwarded, feature tests need to be done
- * before spawning threads with igt_fork().
- */
-void igt_waitchildren(void)
+int __igt_waitchildren(void)
 {
 	int err = 0;
 	int count;
@@ -1761,6 +1748,25 @@ void igt_waitchildren(void)
 	}
 
 	num_test_children = 0;
+	return err;
+}
+
+/**
+ * igt_waitchildren:
+ *
+ * Wait for all children forked with igt_fork.
+ *
+ * The magic here is that exit codes from children will be correctly propagated
+ * to the main thread, including the relevant exit code if a child thread failed.
+ * Of course if multiple children failed with different exit codes the resulting
+ * exit code will be non-deterministic.
+ *
+ * Note that igt_skip() will not be forwarded, feature tests need to be done
+ * before spawning threads with igt_fork().
+ */
+void igt_waitchildren(void)
+{
+	int err = __igt_waitchildren();
 	if (err)
 		igt_fail(err);
 }
diff --git a/lib/igt_core.h b/lib/igt_core.h
index bf8cd66c..a73b0649 100644
--- a/lib/igt_core.h
+++ b/lib/igt_core.h
@@ -742,6 +742,7 @@ bool __igt_fork(void);
 	for (int child = 0; child < (num_children); child++) \
 		for (; __igt_fork(); exit(0))
 void igt_child_done(pid_t pid);
+int __igt_waitchildren(void);
 void igt_waitchildren(void);
 void igt_waitchildren_timeout(int seconds, const char *reason);
 
diff --git a/tests/drv_suspend.c b/tests/drv_suspend.c
index 2e39f20a..9a9ff200 100644
--- a/tests/drv_suspend.c
+++ b/tests/drv_suspend.c
@@ -161,6 +161,57 @@ test_sysfs_reader(bool hibernate)
 }
 
 static void
+test_shrink(int fd, unsigned int mode)
+{
+	uint64_t *can_mlock, pin;
+
+	gem_quiescent_gpu(fd);
+	intel_purge_vm_caches(fd);
+
+	pin = (intel_get_total_ram_mb() + 1) << 20;
+
+	igt_debug("Total memory %'"PRIu64" B (%'"PRIu64" MiB)\n",
+		  pin, pin >> 20);
+	can_mlock = mmap(NULL, pin, PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
+	igt_require(can_mlock != MAP_FAILED);
+
+	/* Lock all the system memory, forcing the driver into swap and OOM */
+	for (uint64_t inc = 64 << 20; inc >= 4 << 10; inc >>= 1) {
+		igt_debug("Testing+ %'"PRIu64" B (%'"PRIu64" MiB)\n",
+			  *can_mlock, *can_mlock >> 20);
+
+		igt_fork(child, 1) {
+			for (uint64_t bytes = *can_mlock;
+			     bytes <= pin;
+			     bytes += inc) {
+				if (mlock(can_mlock, bytes))
+					break;
+
+				*can_mlock = bytes;
+				__sync_synchronize();
+			}
+		}
+		__igt_waitchildren();
+	}
+
+	intel_purge_vm_caches(fd);
+
+	igt_require(*can_mlock > 64 << 20);
+	*can_mlock -= 64 << 20;
+
+	igt_debug("Locking %'"PRIu64" B (%'"PRIu64" MiB)\n",
+		  *can_mlock, *can_mlock >> 20);
+	igt_assert(!mlock(can_mlock, *can_mlock));
+	igt_info("Locked %'"PRIu64" B (%'"PRIu64" MiB)\n",
+		 *can_mlock, *can_mlock >> 20);
+
+	intel_purge_vm_caches(fd);
+	igt_system_suspend_autoresume(mode, SUSPEND_TEST_NONE);
+
+	munmap(can_mlock, pin);
+}
+
+static void
 test_forcewake(int fd, bool hibernate)
 {
 	int fw_fd;
@@ -199,6 +250,9 @@ igt_main
 	igt_subtest("sysfs-reader")
 		test_sysfs_reader(false);
 
+	igt_subtest("shrink")
+		test_shrink(fd, SUSPEND_STATE_MEM);
+
 	igt_subtest("forcewake")
 		test_forcewake(fd, false);