Files
linux/tools/testing/selftests/resctrl
Ilpo Järvinen 345e8abe4c selftests/resctrl: Get domain id from cache id
Domain id is acquired differently depending on CPU. AMD tests use id
from L3 cache, whereas CPUs from other vendors base the id on topology
package id. In order to support L2 CAT test, this has to be
generalized.

The driver side code seems to get the domain ids from cache ids so the
approach used by the AMD branch seems to match the kernel-side code. It
will also work with L2 domain IDs as long as the cache level is
generalized.

Using the topology id was always fragile due to mismatch with the
kernel-side way to acquire the domain id. It got incorrect domain id,
e.g., when Cluster-on-Die (CoD) is enabled for CPU (but CoD is not well
suited for resctrl in the first place so it has not been a big issue if
tests don't work correctly with it).

Taking all the above into account, generalize acquiring the domain id
by taking it from the cache id and do not hard-code the cache level.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13 13:56:45 -07:00
..

resctrl_tests - resctrl file system test suit

Authors:
	Fenghua Yu <fenghua.yu@intel.com>
	Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,

resctrl_tests tests various resctrl functionalities and interfaces including
both software and hardware.

Currently it supports Memory Bandwidth Monitoring test and Memory Bandwidth
Allocation test on Intel RDT hardware. More tests will be added in the future.
And the test suit can be extended to cover AMD QoS and ARM MPAM hardware
as well.

resctrl_tests can be run with or without kselftest framework.

WITH KSELFTEST FRAMEWORK
=======================

BUILD
-----

Build executable file "resctrl_tests" from top level directory of the kernel source:
 $ make -C tools/testing/selftests TARGETS=resctrl

RUN
---

Run resctrl_tests as sudo or root since the test needs to mount resctrl file
system and change contents in the file system.
Using kselftest framework will run all supported tests within resctrl_tests:

 $ sudo make -C tools/testing/selftests TARGETS=resctrl run_tests

More details about kselftest framework can be found in
Documentation/dev-tools/kselftest.rst.

WITHOUT KSELFTEST FRAMEWORK
===========================

BUILD
-----

Build executable file "resctrl_tests" from this directory(tools/testing/selftests/resctrl/):
  $ make

RUN
---

Run resctrl_tests as sudo or root since the test needs to mount resctrl file
system and change contents in the file system.
Executing the test without any parameter will run all supported tests:

 $ sudo ./resctrl_tests

OVERVIEW OF EXECUTION
=====================

A test case has four stages:

  - setup: mount resctrl file system, create group, setup schemata, move test
    process pids to tasks, start benchmark.
  - execute: let benchmark run
  - verify: get resctrl data and verify the data with another source, e.g.
    perf event.
  - teardown: umount resctrl and clear temporary files.

ARGUMENTS
=========

Parameter '-h' shows usage information.

usage: resctrl_tests [-h] [-b "benchmark_cmd [options]"] [-t test list] [-n no_of_bits]
        -b benchmark_cmd [options]: run specified benchmark for MBM, MBA and CMT default benchmark is builtin fill_buf
        -t test list: run tests specified in the test list, e.g. -t mbm,mba,cmt,cat
        -n no_of_bits: run cache tests using specified no of bits in cache bit mask
        -p cpu_no: specify CPU number to run the test. 1 is default
        -h: help