[PATCH v2 blktests 1/5] tests/throtl: add first test for blk-throttle

[Yu Kuai <yukuai1@huaweicloud.com>]

From: Yu Kuai <yukuai3@huawei.com>

Test basic functionality.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
 tests/throtl/001     | 39 ++++++++++++++++++++++++
 tests/throtl/001.out |  6 ++++
 tests/throtl/rc      | 71 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 116 insertions(+)
 create mode 100755 tests/throtl/001
 create mode 100644 tests/throtl/001.out
 create mode 100644 tests/throtl/rc

diff --git a/tests/throtl/001 b/tests/throtl/001
new file mode 100755
index 0000000..739efe2
--- /dev/null
+++ b/tests/throtl/001
@@ -0,0 +1,39 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-3.0+
+# Copyright (C) 2024 Yu Kuai
+#
+# Test basic functionality of blk-throttle
+
+. tests/throtl/rc
+
+DESCRIPTION="basic functionality"
+QUICK=1
+
+test() {
+	echo "Running ${TEST_NAME}"
+
+	if ! _set_up_test nr_devices=1; then
+		return 1;
+	fi
+
+	bps_limit=$((1024 * 1024))
+
+	_set_limits wbps=$bps_limit
+	_test_io write 4k 256
+	_remove_limits
+
+	_set_limits wiops=256
+	_test_io write 4k 256
+	_remove_limits
+
+	_set_limits rbps=$bps_limit
+	_test_io read 4k 256
+	_remove_limits
+
+	_set_limits riops=256
+	_test_io read 4k 256
+	_remove_limits
+
+	_clean_up_test
+	echo "Test complete"
+}
diff --git a/tests/throtl/001.out b/tests/throtl/001.out
new file mode 100644
index 0000000..a3edfdd
--- /dev/null
+++ b/tests/throtl/001.out
@@ -0,0 +1,6 @@
+Running throtl/001
+1
+1
+1
+1
+Test complete
diff --git a/tests/throtl/rc b/tests/throtl/rc
new file mode 100644
index 0000000..871102c
--- /dev/null
+++ b/tests/throtl/rc
@@ -0,0 +1,71 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-3.0+
+# Copyright (C) 2024 Yu Kuai
+#
+# Tests for blk-throttle
+
+. common/rc
+. common/null_blk
+
+CG=/sys/fs/cgroup
+TEST_DIR=$CG/blktests_throtl
+devname=nullb0
+
+group_requires() {
+	_have_root
+	_have_null_blk
+	_have_kernel_option BLK_DEV_THROTTLING
+	_have_cgroup2_controller io
+}
+
+# Create a new null_blk device, and create a new blk-cgroup for test.
+_set_up_test() {
+	if ! _init_null_blk "$*"; then
+		return 1;
+	fi
+
+	echo +io > $CG/cgroup.subtree_control
+	mkdir $TEST_DIR
+
+	return 0;
+}
+
+_clean_up_test() {
+	rmdir $TEST_DIR
+	echo -io > $CG/cgroup.subtree_control
+	_exit_null_blk
+}
+
+_set_limits() {
+	dev=$(cat /sys/block/$devname/dev)
+	echo "$dev $*" > $TEST_DIR/io.max
+}
+
+_remove_limits() {
+	dev=$(cat /sys/block/$devname/dev)
+	echo "$dev rbps=max wbps=max riops=max wiops=max" > $TEST_DIR/io.max
+}
+
+# Create an asynchronous thread and bind it to the specified blk-cgroup, issue
+# IO and then print time elapsed to the second, blk-throttle limits should be
+# set before this function.
+_test_io() {
+	{
+		sleep 0.1
+		start_time=$(date +%s.%N)
+
+		if [ "$1" == "read" ]; then
+			dd if=/dev/$devname of=/dev/null bs="$2" count="$3" iflag=direct status=none
+		elif [ "$1" == "write" ]; then
+			dd of=/dev/$devname if=/dev/zero bs="$2" count="$3" oflag=direct status=none
+		fi
+
+		end_time=$(date +%s.%N)
+		elapsed=$(echo "$end_time - $start_time" | bc)
+		printf "%.0f\n" "$elapsed"
+	} &
+
+	pid=$!
+	echo "$pid" > $TEST_DIR/cgroup.procs
+	wait $pid
+}
-- 
2.39.2