[RFC][PATCH] btrfs: random read fio test for read policy

[RFC][PATCH] btrfs: random read fio test for read policy

[Anand Jain]

There are two objectives of this test case. 1. by default, with
LOAD_FACTOR = 1, it sanity tests the read policies. And 2. Run the
test case individually with a larger LOAD_FACTOR. For example, 10
for the comparative study of the read policy performance.

LOAD_FACTOR parameter controls the fio scalability. For the
LOAD_FACTOR = 1 (default), this runs fio for file size = 1G and num
of jobs = 1, which approximately takes 65s to finish.

This test case runs fio for raid1/10/1c3/1c4 profiles and all the
available read policies in the system. At the end of the test case,
a comparative summary of the result is in the $seqresfull-file.

I find tests/btrfs as the placeholder for this test case. As it
contains many things which are btrfs specific and didn't fit well
under perf.

Feedback/suggestions welcome.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 tests/btrfs/231     | 145 ++++++++++++++++++++++++++++++++++++++++++++
 tests/btrfs/231.out |   2 +
 tests/btrfs/group   |   1 +
 3 files changed, 148 insertions(+)
 create mode 100755 tests/btrfs/231
 create mode 100644 tests/btrfs/231.out

diff --git a/tests/btrfs/231 b/tests/btrfs/231
new file mode 100755
index 000000000000..c08b5826f60a
--- /dev/null
+++ b/tests/btrfs/231
@@ -0,0 +1,145 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2021 Anand Jain.  All Rights Reserved.
+#
+# FS QA Test 231
+#
+# Random read fio test for raid1(10)(c3)(c4) with available
+# read policy.
+# 
+#
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+fio_config=$tmp.fio
+fio_results=$tmp.fio_out
+
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+
+# Modify as appropriate.
+_supported_fs btrfs
+_require_scratch_dev_pool 4
+
+njob=$LOAD_FACTOR
+size=$LOAD_FACTOR
+_require_scratch_size $(($size * 2 * 1024 * 1024))
+echo size=$size njob=$njob >> $seqres.full
+
+make_fio_config()
+{
+	#Set direct IO to true, help to avoid buffered IO so that read happens
+	#from the devices.
+	cat >$fio_config <<EOF
+[global]
+bs=64K
+iodepth=64
+direct=1
+invalidate=1
+allrandrepeat=1
+ioengine=libaio
+group_reporting
+size=${size}G
+rw=randread
+EOF
+}
+#time_based
+#runtime=5
+
+make_fio_config
+for job in $(seq 0 $njob); do
+	echo "[foo$job]" >> $fio_config
+	echo  "filename=$SCRATCH_MNT/$job/file" >> $fio_config
+done
+_require_fio $fio_config
+cat $fio_config >> $seqres.full
+
+work()
+{
+ 	raid=$1
+
+	echo ------------- profile: $raid ---------- >> $seqres.full
+	echo >> $seqres.full
+	_scratch_pool_mkfs $raid >> $seqres.full 2>&1
+	_scratch_mount
+
+	fsid=$($BTRFS_UTIL_PROG filesystem show -m $SCRATCH_MNT | grep uuid: | \
+	     $AWK_PROG '{print $4}')
+	readpolicy_path="/sys/fs/btrfs/$fsid/read_policy"
+	policies=$(cat $readpolicy_path | sed 's/\[//g' | sed 's/\]//g')
+
+	for policy in $policies; do
+		echo $policy > $readpolicy_path || _fail "Fail to set readpolicy"
+		echo -n "activating readpolicy: " >> $seqres.full
+		cat $readpolicy_path >> $seqres.full
+		echo >> $seqres.full
+
+		> $fio_results
+		$FIO_PROG --output=$fio_results $fio_config
+		cat $fio_results >> $seqres.full
+	done
+
+	_scratch_unmount
+	_scratch_dev_pool_put
+}
+
+_scratch_dev_pool_get 2
+work "-m raid1 -d single"
+
+_scratch_dev_pool_get 2
+work "-m raid1 -d raid1"
+
+_scratch_dev_pool_get 4
+work "-m raid10 -d raid10"
+
+_scratch_dev_pool_get 3
+work "-m raid1c3 -d raid1c3"
+
+_scratch_dev_pool_get 4
+work "-m raid1c4 -d raid1c4"
+
+
+# Now benchmark the raw device performance
+> $fio_config
+make_fio_config
+_scratch_dev_pool_get 4
+for dev in $SCRATCH_DEV_POOL; do
+	echo "[$dev]" >> $fio_config
+	echo  "filename=$dev" >> $fio_config
+done
+_require_fio $fio_config
+cat $fio_config >> $seqres.full
+
+echo ------------- profile: raw disk ---------- >> $seqres.full
+echo >> $seqres.full
+> $fio_results
+$FIO_PROG --output=$fio_results $fio_config
+cat $fio_results >> $seqres.full
+
+echo >> $seqres.full
+echo ===== Summary ====== >> $seqres.full
+cat $seqres.full | egrep -A1 "Run status|Disk stats|profile:|readpolicy" >> $seqres.full
+
+echo "Silence is golden"
+
+# success, all done
+status=0
+exit
diff --git a/tests/btrfs/231.out b/tests/btrfs/231.out
new file mode 100644
index 000000000000..a31b87a289bf
--- /dev/null
+++ b/tests/btrfs/231.out
@@ -0,0 +1,2 @@
+QA output created by 231
+Silence is golden
diff --git a/tests/btrfs/group b/tests/btrfs/group
index a7c6598326c4..7f449d1db99e 100644
--- a/tests/btrfs/group
+++ b/tests/btrfs/group
@@ -233,3 +233,4 @@
 228 auto quick volume
 229 auto quick send clone
 230 auto quick qgroup limit
+231 other
-- 
2.27.0