lisa.wlgen.fio: Introduce Fio as Workload

Fio is a highly-configurable I/O tester used by the block layer for testing
and as a general benchmark tool for storage. Even for scheduler investigations
Fio is interesting as in_iowait-setting tasks are treated differently.
To be able to create tests for them we introduce a simplistic lisa frontend.

Fio Workloads can now be created like:

ftest = Fio(target, filename="/dev/nvme0n1", name="test", rw="randread", runtime=50, bs='4k')
and then ran like any other:

with ftest:
    result = fiotestmmc.run()
    print(result.read_iops)

Signed-off-by: Christian Loehle <[email protected]>

lisa/wlgen/fio.py

@@ -0,0 +1,140 @@
+# SPDX-License-Identifier: Apache-2.0
+#
+# Copyright (C) 2023, Arm Limited and contributors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+"""
+Fio is a widely used I/O benchmarking tool that is highly configurable.
+We use it as in_iowait tasks are treated differently than just blocked tasks,
+so anything involving that cannot be generated just with rt-app
+"""
+
+import re
+from shlex import quote
+
+from lisa.utils import memoized, kwargs_forwarded_to
+from lisa.wlgen.workload import Workload
+
+
+class FioOutput(str):
+    """
+    A wrapper around fio's terse format output to access some results
+    XXX: Could also be parsed as json, but will we ever need more than iops?
+    terse output format is guaranteed to be at stable offsets.
+    """
+
+    @property
+    @memoized
+    def read_iops(self):
+        """
+        Number of read IOPS as reported by fio
+        """
+        return int(self.split(';')[7])
+
+
+class Fio(Workload):
+    """
+    A fio workload
+
+    :param target: The Target on which to execute this workload
+    :type target: Target
+
+    :param filename: Filename for fio to operate on (can be block device)
+    :type filename: str
+
+    :param testname: The test name passed on to fio
+    :type filename: str
+
+    :param rw: The mode of operation for fio, e.g. randread, read, rw
+    :type rw: str
+
+    :param bs: The blocksize as a fio-accepted string (e.g. 512B, 4K, 1M)
+    :type bs: str
+
+    :param runtime: The time the test should be running for (defaults to seconds)
+    :type runtime: str
+
+    :param ioengine: The ioengine for fio to use (e.g. psync, libaio, io_uring)
+    :type ioengine: str
+
+    :param iodepth: The number of requests in-flight at once
+    :type iodepth: int
+
+    :param numjobs: The number of processes to run this as, will be reported together
+    :type numjobs: int
+
+    :param cpus_allowed: The set of cpus the fio tasks are allowed on
+    :type cpus_allowed: str
+
+    :param cli_options: Dictionary of cli_options passed to fio command line. Run
+        ``fio --help`` for available parameters. Character
+        ``_`` in option names is replaced by ``-``.
+    :type cli_options: dict(str, object)
+
+    :Variable keyword arguments: Forwarded to :class:`lisa.wlgen.workload.Workload`
+    """
+
+    @kwargs_forwarded_to(
+        Workload.__init__,
+        ignore=['command'],
+    )
+    def __init__(self, target, *,
+        filename,
+	testname='fiotest',
+	rw='randread',
+	bs='4k',
+	runtime=None,
+	ioengine="psync",
+	iodepth=1,
+	numjobs=1,
+	cpus_allowed=None,
+        cli_options=None,
+        **kwargs
+    ):
+
+        arg_list = ['fio'] + ['--minimal'] # minimal is terse output format
+        cli_options = cli_options.copy() if cli_options else {}
+        cli_options['name'] = testname
+        cli_options['filename'] = filename
+
+        if runtime:
+            arg_list += ['--time_based']
+            cli_options['runtime'] = runtime
+
+        if numjobs > 1:
+            arg_list += ['--group_reporting'] # We always want just one report
+            cli_options['numjobs'] = f"{numjobs}"
+
+        cli_options['rw'] = rw
+        cli_options['bs'] = bs
+        cli_options['ioengine'] = ioengine
+        cli_options['iodepth'] = iodepth
+
+        if cpus_allowed:
+            cli_options['cpus_allowed'] = cpus_allowed
+
+        arg_list = arg_list + [
+            quote(f"--{arg}={value}")
+            for arg, value in cli_options.items()
+        ]
+
+        command = ' '.join(arg_list)
+
+        super().__init__(target=target, command=command, **kwargs)
+
+    def _run(self):
+        out = yield self._basic_run()
+        return FioOutput(out['stdout'])
+
+# vim :set tabstop=4 shiftwidth=4 textwidth=80 expandtab