Base
====
Since the original series [1] was merged into Andrew's tree, some issues were
noticed. Up to this point, we had been working on fixing what's in Andrew's
tree [2], but at this point we've changed direction enough that a lot of the
fix's delta is undoing what was done in the original series, thereby making it
hard to review.
As suggested by Hugh Dickins and Peter Xu, this series takes a step back. It can
be considered a v3 of the original series [1] - it combines those patches with
the fixes, reordered / broken up to allow for easier review.
The idea is that it will apply cleanly to akpm's tree, *replacing* the following
patches (i.e., drop these first, and then apply this series):
userfaultfd-support-minor-fault-handling-for-shmem.patch
userfaultfd-support-minor-fault-handling-for-shmem-fix.patch
userfaultfd-support-minor-fault-handling-for-shmem-fix-2.patch
userfaultfd-support-minor-fault-handling-for-shmem-fix-3.patch
userfaultfd-support-minor-fault-handling-for-shmem-fix-4.patch
userfaultfd-selftests-use-memfd_create-for-shmem-test-type.patch
userfaultfd-selftests-create-alias-mappings-in-the-shmem-test.patch
userfaultfd-selftests-reinitialize-test-context-in-each-test.patch
userfaultfd-selftests-exercise-minor-fault-handling-shmem-support.patch
Changelog
=========
Changes since the most recent fixup patch [2]:
- Squash the fixes ([2]) in with the original series ([1]). This makes reviewing
easier, as we no longer have to sift through deltas undoing what we had done
before. [Hugh, Peter]
- Modify shmem_mcopy_atomic_pte() to use the new mcopy_atomic_install_ptes()
helper, reducing code duplication. [Hugh]
- Properly trigger handle_userfault() in the shmem_swapin_page() case. [Hugh]
- Use shmem_getpage() instead of find_lock_page() to lookup the existing page in
for continue. This properly deals with swapped-out pages. [Hugh]
- Unconditionally pte_mkdirty() for anon memory (as before). [Peter]
- Don't include userfaultfd_k.h in either hugetlb.h or shmem_fs.h. [Hugh]
- Add comment for UFFD_FEATURE_MINOR_SHMEM (to match _HUGETLBFS). [Hugh]
- Fix some small cleanup issues (parens, reworded conditionals, reduced plumbing
of some parameters, simplify labels/gotos, ...). [Hugh, Peter]
Overview
========
See the series which added minor faults for hugetlbfs [3] for a detailed
overview of minor fault handling in general. This series adds the same support
for shmem-backed areas.
This series is structured as follows:
- Commits 1 and 2 are cleanups.
- Commits 3 and 4 implement the new feature (minor fault handling for shmem).
- Commits 5, 6, 7, 8 update the userfaultfd selftest to exercise the feature.
- Commit 9 is one final cleanup, modifying an existing code path to re-use a new
helper we've introduced. We rely on the selftest to show that this change
doesn't break anything.
Use Case
========
In some cases it is useful to have VM memory backed by tmpfs instead of
hugetlbfs. So, this feature will be used to support the same VM live migration
use case described in my original series.
Additionally, Android folks (Lokesh Gidra <lokeshgidra(a)google.com>) hope to
optimize the Android Runtime garbage collector using this feature:
"The plan is to use userfaultfd for concurrently compacting the heap. With
this feature, the heap can be shared-mapped at another location where the
GC-thread(s) could continue the compaction operation without the need to
invoke userfault ioctl(UFFDIO_COPY) each time. OTOH, if and when Java threads
get faults on the heap, UFFDIO_CONTINUE can be used to resume execution.
Furthermore, this feature enables updating references in the 'non-moving'
portion of the heap efficiently. Without this feature, uneccessary page
copying (ioctl(UFFDIO_COPY)) would be required."
[1] https://lore.kernel.org/patchwork/cover/1388144/
[2] https://lore.kernel.org/patchwork/patch/1408161/
[3] https://lore.kernel.org/linux-fsdevel/20210301222728.176417-1-axelrasmussen…
Axel Rasmussen (9):
userfaultfd/hugetlbfs: avoid including userfaultfd_k.h in hugetlb.h
userfaultfd/shmem: combine shmem_{mcopy_atomic,mfill_zeropage}_pte
userfaultfd/shmem: support minor fault registration for shmem
userfaultfd/shmem: support UFFDIO_CONTINUE for shmem
userfaultfd/selftests: use memfd_create for shmem test type
userfaultfd/selftests: create alias mappings in the shmem test
userfaultfd/selftests: reinitialize test context in each test
userfaultfd/selftests: exercise minor fault handling shmem support
userfaultfd/shmem: modify shmem_mcopy_atomic_pte to use install_ptes
fs/userfaultfd.c | 6 +-
include/linux/hugetlb.h | 5 +-
include/linux/shmem_fs.h | 15 +-
include/linux/userfaultfd_k.h | 5 +
include/uapi/linux/userfaultfd.h | 7 +-
mm/hugetlb.c | 1 +
mm/memory.c | 8 +-
mm/shmem.c | 122 ++++------
mm/userfaultfd.c | 183 ++++++++++-----
tools/testing/selftests/vm/userfaultfd.c | 280 +++++++++++++++--------
10 files changed, 387 insertions(+), 245 deletions(-)
--
2.31.1.295.g9ea45b61b8-goog
The rp_filter testcase is used to test whether local packets redirected
from dummy1 to lo could pass the checking of rp_filter.
In fact, the packets passed the checking, but the testing process cannot
receive any reply packets, leading to test failure. The reason is that
the device dummy1 lacks ip address, caused the incorrect routing of
reply packets.
This patch adds ip address for dummy1 device.
Signed-off-by: Qiao Ma <mqaio(a)linux.alibaba.com>
---
tools/testing/selftests/net/fib_tests.sh | 1 +
1 file changed, 1 insertion(+)
diff --git a/tools/testing/selftests/net/fib_tests.sh b/tools/testing/selftests/net/fib_tests.sh
index 2b5707738609..9a843ca0b913 100755
--- a/tools/testing/selftests/net/fib_tests.sh
+++ b/tools/testing/selftests/net/fib_tests.sh
@@ -448,6 +448,7 @@ fib_rp_filter_test()
$IP link set dummy0 address 52:54:00:6a:c7:5e
$IP link add dummy1 type dummy
$IP link set dummy1 address 52:54:00:6a:c7:5e
+ $IP address add 198.51.101.1/24 dev dummy1
$IP link set dev dummy1 up
$NS_EXEC sysctl -qw net.ipv4.conf.all.rp_filter=1
$NS_EXEC sysctl -qw net.ipv4.conf.all.accept_local=1
--
2.18.2
The kernel now has a number of testing and debugging tools, and we've
seen a bit of confusion about what the differences between them are.
Add a basic documentation outlining the testing tools, when to use each,
and how they interact.
This is a pretty quick overview rather than the idealised "kernel
testing guide" that'd probably be optimal, but given the number of times
questions like "When do you use KUnit and when do you use Kselftest?"
are being asked, it seemed worth at least having something. Hopefully
this can form the basis for more detailed documentation later.
Signed-off-by: David Gow <davidgow(a)google.com>
---
Thanks, everyone, for the comments on the doc. I've made a few of the
suggested changes. Please let me know what you think!
-- David
Changes since v1:
https://lore.kernel.org/linux-kselftest/20210410070529.4113432-1-davidgow@g…
- Note KUnit's speed and that one should provide selftests for syscalls
- Mention lockdep as a Dynamic Analysis Tool
- Refer to "Dynamic Analysis Tools" instead of "Sanitizers"
- A number of minor formatting tweaks and rewordings for clarity.
Not changed:
- I haven't included an exhaustive list of differences, advantages, etc,
between KUnit and kselftest: for now, the doc continues to focus on
the difference between 'in-kernel' and 'userspace' testing here.
- Similarly, I'm not linking out to docs defining and describing "Unit"
tests versus "End-to-end" tests. None of the existing documentation
elsewhere quite matches what we do in the kernel perfectly, so it
seems less confusing to focus on the 'in-kernel'/'userspace'
distinction, and leave other definitions as a passing mention for
those who are already familiar with the concepts.
- I haven't linked to any talk videos here: a few of them are linked on
(e.g.) the KUnit webpage, but I wanted to keep the Kernel documentation
more self-contained for now. No objection to adding them in a follow-up
patch if people feel strongly about it, though.
- The link from index.rst to this doc is unchanged. I personally think
that the link is prominent enough there: it's the first link, and
shows up a few times. One possibility if people disagreed would be to
merge this page with the index, but given not all dev-tools are going
to be testing-related, it seemed a bit arrogant. :-)
Documentation/dev-tools/index.rst | 3 +
Documentation/dev-tools/testing-overview.rst | 117 +++++++++++++++++++
2 files changed, 120 insertions(+)
create mode 100644 Documentation/dev-tools/testing-overview.rst
diff --git a/Documentation/dev-tools/index.rst b/Documentation/dev-tools/index.rst
index 1b1cf4f5c9d9..f590e5860794 100644
--- a/Documentation/dev-tools/index.rst
+++ b/Documentation/dev-tools/index.rst
@@ -7,6 +7,8 @@ be used to work on the kernel. For now, the documents have been pulled
together without any significant effort to integrate them into a coherent
whole; patches welcome!
+A brief overview of testing-specific tools can be found in :doc:`testing-overview`.
+
.. class:: toc-title
Table of contents
@@ -14,6 +16,7 @@ whole; patches welcome!
.. toctree::
:maxdepth: 2
+ testing-overview
coccinelle
sparse
kcov
diff --git a/Documentation/dev-tools/testing-overview.rst b/Documentation/dev-tools/testing-overview.rst
new file mode 100644
index 000000000000..ce36a8cdf6b5
--- /dev/null
+++ b/Documentation/dev-tools/testing-overview.rst
@@ -0,0 +1,117 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+====================
+Kernel Testing Guide
+====================
+
+
+There are a number of different tools for testing the Linux kernel, so knowing
+when to use each of them can be a challenge. This document provides a rough
+overview of their differences, and how they fit together.
+
+
+Writing and Running Tests
+=========================
+
+The bulk of kernel tests are written using either the kselftest or KUnit
+frameworks. These both provide infrastructure to help make running tests and
+groups of tests easier, as well as providing helpers to aid in writing new
+tests.
+
+If you're looking to verify the behaviour of the Kernel — particularly specific
+parts of the kernel — then you'll want to use KUnit or kselftest.
+
+
+The Difference Between KUnit and kselftest
+------------------------------------------
+
+KUnit (Documentation/dev-tools/kunit/index.rst) is an entirely in-kernel system
+for "white box" testing: because test code is part of the kernel, it can access
+internal structures and functions which aren't exposed to userspace.
+
+KUnit tests therefore are best written against small, self-contained parts
+of the kernel, which can be tested in isolation. This aligns well with the
+concept of 'unit' testing.
+
+For example, a KUnit test might test an individual kernel function (or even a
+single codepath through a function, such as an error handling case), rather
+than a feature as a whole.
+
+This also makes KUnit tests very fast to build and run, allowing them to be
+run frequently as part of the development process.
+
+There is a KUnit test style guide which may give further pointers in
+Documentation/dev-tools/kunit/style.rst
+
+
+kselftest (Documentation/dev-tools/kselftest.rst), on the other hand, is
+largely implemented in userspace, and tests are normal userspace scripts or
+programs.
+
+This makes it easier to write more complicated tests, or tests which need to
+manipulate the overall system state more (e.g., spawning processes, etc.).
+However, it's not possible to call kernel functions directly from kselftest.
+This means that only kernel functionality which is exposed to userspace somhow
+(e.g. by a syscall, device, filesystem, etc.) can be tested with kselftest. To
+work around this, some tests include a companion kernel module which exposes
+more information or functionality. If a test runs mostly or entirely within the
+kernel, however, KUnit may be the more appropriate tool.
+
+kselftest is therefore suited well to tests of whole features, as these will
+expose an interface to userspace, which can be tested, but not implementation
+details. This aligns well with 'system' or 'end-to-end' testing.
+
+For example, all new system calls should be accompanied by kselftest tests.
+
+Code Coverage Tools
+===================
+
+The Linux Kernel supports two different code coverage measurement tools. These
+can be used to verify that a test is executing particular functions or lines
+of code. This is useful for determining how much of the kernel is being tested,
+and for finding corner-cases which are not covered by the appropriate test.
+
+:doc:`gcov` is GCC's coverage testing tool, which can be used with the kernel
+to get global or per-module coverage. Unlike KCOV, it does not record per-task
+coverage. Coverage data can be read from debugfs, and interpreted using the
+usual gcov tooling.
+
+:doc:`kcov` is a feature which can be built in to the kernel to allow
+capturing coverage on a per-task level. It's therefore useful for fuzzing and
+other situations where information about code executed during, for example, a
+single syscall is useful.
+
+
+Dynamic Analysis Tools
+======================
+
+The kernel also supports a number of dynamic analysis tools, which attempt to
+detect classes of issues when the occur in a running kernel. These typically
+look for undefined behaviour of some kind, such as invalid memory accesses,
+concurrency issues such as data races, or other undefined behaviour like
+integer overflows.
+
+Some of these tools are listed below:
+
+* kmemleak detects possible memory leaks. See
+ Documentation/dev-tools/kmemleak.rst
+* KASAN detects invalid memory accesses such as out-of-bounds and
+ use-after-free errors. See Documentation/dev-tools/kasan.rst
+* UBSAN detects behaviour that is undefined by the C standard, like integer
+ overflows. See Documentation/dev-tools/ubsan.rst
+* KCSAN detects data races. See Documentation/dev-tools/kcsan.rst
+* KFENCE is a low-overhead detector of memory issues, which is much faster than
+ KASAN and can be used in production. See Documentation/dev-tools/kfence.rst
+* lockdep is a locking correctness validator. See
+ Documentation/locking/lockdep-design.rst
+* There are several other pieces of debug instrumentation in the kernel, many
+ of which can be found in lib/Kconfig.debug
+
+These tools tend to test the kernel as a whole, and do not "pass" like
+kselftest or KUnit tests. They can be combined with KUnit or kselftest by
+running tests on a kernel with a sanitizer enabled: you can then be sure
+that none of these errors are occurring during the test.
+
+Some of these tools integrate with KUnit or kselftest and will
+automatically fail tests if an issue is detected.
+
--
2.31.1.295.g9ea45b61b8-goog
This is long overdue.
There are several things that aren't nailed down (in-tree
.kunitconfig's), or partially broken (GCOV on UML), but having them
documented, warts and all, is better than having nothing.
This covers a bunch of the more recent features
* kunit_filter_glob
* kunit.py run --kunitconfig
* slightly more detail on building tests as modules
* CONFIG_KUNIT_DEBUGFS
By my count, the only headline features now not mentioned are the KASAN
integration and KernelCI json output support (kunit.py run --json).
And then it also discusses how to get code coverage reports under UML
and non-UML since this is a question people have repeatedly asked.
Non-UML coverage collection is no different from normal, but we should
probably explicitly call this out.
As for UML, I was able to get it working again with two small hacks.*
E.g. with CONFIG_KUNIT=y && CONFIG_KUNIT_ALL_TESTS=y
Overall coverage rate:
lines......: 15.1% (18294 of 120776 lines)
functions..: 16.8% (1860 of 11050 functions)
Note: this doesn't document --alltests since this is not stable yet.
Hopefully being run more frequently as part of KernelCI will help...
*Using gcc/gcov-6 and not using uml_abort() in os_dump_core().
I've documented these hacks in "Notes" but left TODOs for
brendanhiggins(a)google.com who tracked down the runtime issue in GCC.
To be clear: these are not issues specific to KUnit, but rather to UML.
Signed-off-by: Daniel Latypov <dlatypov(a)google.com>
---
v2 -> v3:
* Suggest --make_options=CC=/usr/bin/gcc-6 instead of manually editing
kunit_kernel.py
* update instructions on how to remove uml_abort() call
v1 -> v2:
Fix typos, drop --alltests, changed wordiing on config fragments.
---
Documentation/dev-tools/kunit/index.rst | 1 +
.../dev-tools/kunit/running_tips.rst | 258 ++++++++++++++++++
Documentation/dev-tools/kunit/start.rst | 2 +
3 files changed, 261 insertions(+)
create mode 100644 Documentation/dev-tools/kunit/running_tips.rst
diff --git a/Documentation/dev-tools/kunit/index.rst b/Documentation/dev-tools/kunit/index.rst
index 848478838347..7f7cf8d2ab20 100644
--- a/Documentation/dev-tools/kunit/index.rst
+++ b/Documentation/dev-tools/kunit/index.rst
@@ -14,6 +14,7 @@ KUnit - Unit Testing for the Linux Kernel
style
faq
tips
+ running_tips
What is KUnit?
==============
diff --git a/Documentation/dev-tools/kunit/running_tips.rst b/Documentation/dev-tools/kunit/running_tips.rst
new file mode 100644
index 000000000000..e2e9af711d1b
--- /dev/null
+++ b/Documentation/dev-tools/kunit/running_tips.rst
@@ -0,0 +1,258 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+============================
+Tips For Running KUnit Tests
+============================
+
+Using ``kunit.py run`` ("kunit tool")
+=====================================
+
+Running from any directory
+--------------------------
+
+It can be handy to create a bash function like:
+
+.. code-block:: bash
+
+ function run_kunit() {
+ ( cd "$(git rev-parse --show-toplevel)" && ./tools/testing/kunit/kunit.py run $@ )
+ }
+
+.. note::
+ Early versions of ``kunit.py`` (before 5.6) didn't work unless run from
+ the kernel root, hence the use of a subshell and ``cd``.
+
+Running a subset of tests
+-------------------------
+
+``kunit.py run`` accepts an optional glob argument to filter tests. Currently
+this only matches against suite names, but this may change in the future.
+
+Say that we wanted to run the sysctl tests, we could do so via:
+
+.. code-block:: bash
+
+ $ echo -e 'CONFIG_KUNIT=y\nCONFIG_KUNIT_ALL_TESTS=y' > .kunit/.kunitconfig
+ $ ./tools/testing/kunit/kunit.py run 'sysctl*'
+
+We're paying the cost of building more tests than we need this way, but it's
+easier than fiddling with ``.kunitconfig`` files or commenting out
+``kunit_suite``'s.
+
+However, if we wanted to define a set of tests in a less ad hoc way, the next
+tip is useful.
+
+Defining a set of tests
+-----------------------
+
+``kunit.py run`` (along with ``build``, and ``config``) supports a
+``--kunitconfig`` flag. So if you have a set of tests that you want to run on a
+regular basis (especially if they have other dependencies), you can create a
+specific ``.kunitconfig`` for them.
+
+E.g. kunit has one for its tests:
+
+.. code-block:: bash
+
+ $ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit/.kunitconfig
+
+Alternatively, if you're following the convention of naming your
+file ``.kunitconfig``, you can just pass in the dir, e.g.
+
+.. code-block:: bash
+
+ $ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit
+
+.. note::
+ This is a relatively new feature (5.12+) so we don't have any
+ conventions yet about on what files should be checked in versus just
+ kept around locally. It's up to you and your maintainer to decide if a
+ config is useful enough to submit (and therefore have to maintain).
+
+.. note::
+ Having ``.kunitconfig`` fragments in a parent and child directory is
+ iffy. There's discussion about adding an "import" statement in these
+ files to make it possible to have a top-level config run tests from all
+ child directories. But that would mean ``.kunitconfig`` files are no
+ longer just simple .config fragments.
+
+ One alternative would be to have kunit tool recursively combine configs
+ automagically, but tests could theoretically depend on incompatible
+ options, so handling that would be tricky.
+
+Generating code coverage reports under UML
+------------------------------------------
+
+.. note::
+ TODO(brendanhiggins(a)google.com): There are various issues with UML and
+ versions of gcc 7 and up. You're likely to run into missing ``.gcda``
+ files or compile errors. We know one `faulty GCC commit
+ <https://github.com/gcc-mirror/gcc/commit/8c9434c2f9358b8b8bad2c1990edf10a21…>`_
+ but not how we'd go about getting this fixed. The compile errors still
+ need some investigation.
+
+.. note::
+ TODO(brendanhiggins(a)google.com): for recent versions of Linux
+ (5.10-5.12, maybe earlier), there's a bug with gcov counters not being
+ flushed in UML. This translates to very low (<1%) reported coverage. This is
+ related to the above issue and can be worked around by replacing the
+ one call to ``uml_abort()`` with a plain ``exit()``.
+
+
+This is different from the "normal" way of getting coverage information that is
+documented in Documentation/dev-tools/gcov.rst.
+
+Instead of enabling ``CONFIG_GCOV_KERNEL=y``, we can set these options:
+
+.. code-block:: none
+
+ CONFIG_DEBUG_KERNEL=y
+ CONFIG_DEBUG_INFO=y
+ CONFIG_GCOV=y
+
+
+Putting it together into a copy-pastable sequence of commands:
+
+.. code-block:: bash
+
+ # Append coverage options to the current config
+ $ echo -e "CONFIG_DEBUG_KERNEL=y\nCONFIG_DEBUG_INFO=y\nCONFIG_GCOV=y" >> .kunit/.kunitconfig
+ $ ./tools/testing/kunit/kunit.py run
+ # Extract the coverage information from the build dir (.kunit/)
+ $ lcov -t "my_kunit_tests" -o coverage.info -c -d .kunit/
+
+ # From here on, it's the same process as with CONFIG_GCOV_KERNEL=y
+ # E.g. can generate an HTML report in a tmp dir like so:
+ $ genhtml -o /tmp/coverage_html coverage.info
+
+
+If your installed version of gcc doesn't work, you can tweak the steps:
+
+.. code-block:: bash
+
+ $ ./tools/testing/kunit/kunit.py run --make_options=CC=/usr/bin/gcc-6
+ $ lcov -t "my_kunit_tests" -o coverage.info -c -d .kunit/ --gcov-tool=/usr/bin/gcov-6
+
+
+Running tests manually
+======================
+
+Running tests without using ``kunit.py run`` is also an important use case.
+Currently it's your only option if you want to test on architectures other than
+UML.
+
+As running the tests under UML is fairly straightforward (configure and compile
+the kernel, run the ``./linux`` binary), this section will focus on testing
+non-UML architectures.
+
+
+Running built-in tests
+----------------------
+
+When setting tests to ``=y``, the tests will run as part of boot and print
+results to dmesg in TAP format. So you just need to add your tests to your
+``.config``, build and boot your kernel as normal.
+
+So if we compiled our kernel with:
+
+.. code-block:: none
+
+ CONFIG_KUNIT=y
+ CONFIG_KUNIT_EXAMPLE_TEST=y
+
+Then we'd see output like this in dmesg signaling the test ran and passed:
+
+.. code-block:: none
+
+ TAP version 14
+ 1..1
+ # Subtest: example
+ 1..1
+ # example_simple_test: initializing
+ ok 1 - example_simple_test
+ ok 1 - example
+
+Running tests as modules
+------------------------
+
+Depending on the tests, you can build them as loadable modules.
+
+For example, we'd change the config options from before to
+
+.. code-block:: none
+
+ CONFIG_KUNIT=y
+ CONFIG_KUNIT_EXAMPLE_TEST=m
+
+Then after booting into our kernel, we can run the test via
+
+.. code-block:: none
+
+ $ modprobe kunit-example-test
+
+This will then cause it to print TAP output to stdout.
+
+.. note::
+ The ``modprobe`` will *not* have a non-zero exit code if any test
+ failed (as of 5.13). But ``kunit.py parse`` would, see below.
+
+.. note::
+ You can set ``CONFIG_KUNIT=m`` as well, however, some features will not
+ work and thus some tests might break. Ideally tests would specify they
+ depend on ``KUNIT=y`` in their ``Kconfig``'s, but this is an edge case
+ most test authors won't think about.
+ As of 5.13, the only difference is that ``current->kunit_test`` will
+ not exist.
+
+Pretty-printing results
+-----------------------
+
+You can use ``kunit.py parse`` to parse dmesg for test output and print out
+results in the same familiar format that ``kunit.py run`` does.
+
+.. code-block:: bash
+
+ $ ./tools/testing/kunit/kunit.py parse /var/log/dmesg
+
+
+Retrieving per suite results
+----------------------------
+
+Regardless of how you're running your tests, you can enable
+``CONFIG_KUNIT_DEBUGFS`` to expose per-suite TAP-formatted results:
+
+.. code-block:: none
+
+ CONFIG_KUNIT=y
+ CONFIG_KUNIT_EXAMPLE_TEST=m
+ CONFIG_KUNIT_DEBUGFS=y
+
+The results for each suite will be exposed under
+``/sys/kernel/debug/kunit/<suite>/results``.
+So using our example config:
+
+.. code-block:: bash
+
+ $ modprobe kunit-example-test > /dev/null
+ $ cat /sys/kernel/debug/kunit/example/results
+ ... <TAP output> ...
+
+ # After removing the module, the corresponding files will go away
+ $ modprobe -r kunit-example-test
+ $ cat /sys/kernel/debug/kunit/example/results
+ /sys/kernel/debug/kunit/example/results: No such file or directory
+
+Generating code coverage reports
+--------------------------------
+
+See Documentation/dev-tools/gcov.rst for details on how to do this.
+
+The only vaguely KUnit-specific advice here is that you probably want to build
+your tests as modules. That way you can isolate the coverage from tests from
+other code executed during boot, e.g.
+
+.. code-block:: bash
+
+ # Reset coverage counters before running the test.
+ $ echo 0 > /sys/kernel/debug/gcov/reset
+ $ modprobe kunit-example-test
diff --git a/Documentation/dev-tools/kunit/start.rst b/Documentation/dev-tools/kunit/start.rst
index 0e65cabe08eb..aa56d7ca6bfb 100644
--- a/Documentation/dev-tools/kunit/start.rst
+++ b/Documentation/dev-tools/kunit/start.rst
@@ -236,5 +236,7 @@ Next Steps
==========
* Check out the :doc:`tips` page for tips on
writing idiomatic KUnit tests.
+* Check out the :doc:`running_tips` page for tips on
+ how to make running KUnit tests easier.
* Optional: see the :doc:`usage` page for a more
in-depth explanation of KUnit.
base-commit: de2fcb3e62013738f22bbb42cbd757d9a242574e
--
2.31.1.295.g9ea45b61b8-goog
This is long overdue.
There are several things that aren't nailed down (in-tree
.kunitconfig's), or partially broken (GCOV on UML), but having them
documented, warts and all, is better than having nothing.
This covers a bunch of the more recent features
* kunit_filter_glob
* kunit.py run --kunitconfig
* slightly more detail on building tests as modules
* CONFIG_KUNIT_DEBUGFS
By my count, the only headline features now not mentioned are the KASAN
integration and KernelCI json output support (kunit.py run --json).
And then it also discusses how to get code coverage reports under UML
and non-UML since this is a question people have repeatedly asked.
Non-UML coverage collection is no different from normal, but we should
probably explicitly call this out.
As for UML, I was able to get it working again with two small hacks.*
E.g. with CONFIG_KUNIT=y && CONFIG_KUNIT_ALL_TESTS=y
Overall coverage rate:
lines......: 15.1% (18294 of 120776 lines)
functions..: 16.8% (1860 of 11050 functions)
Note: this doesn't document --alltests since this is not stable yet.
Hopefully being run more frequently as part of KernelCI will help...
*Using gcc/gcov-6 and not using uml_abort() in os_dump_core().
I've documented these hacks in "Notes" but left TODOs for
brendanhiggins(a)google.com who tracked down the runtime issue in GCC.
To be clear: these are not issues specific to KUnit, but rather to UML.
Signed-off-by: Daniel Latypov <dlatypov(a)google.com>
---
Documentation/dev-tools/kunit/index.rst | 1 +
.../dev-tools/kunit/running_tips.rst | 260 ++++++++++++++++++
Documentation/dev-tools/kunit/start.rst | 2 +
3 files changed, 263 insertions(+)
create mode 100644 Documentation/dev-tools/kunit/running_tips.rst
diff --git a/Documentation/dev-tools/kunit/index.rst b/Documentation/dev-tools/kunit/index.rst
index 848478838347..7f7cf8d2ab20 100644
--- a/Documentation/dev-tools/kunit/index.rst
+++ b/Documentation/dev-tools/kunit/index.rst
@@ -14,6 +14,7 @@ KUnit - Unit Testing for the Linux Kernel
style
faq
tips
+ running_tips
What is KUnit?
==============
diff --git a/Documentation/dev-tools/kunit/running_tips.rst b/Documentation/dev-tools/kunit/running_tips.rst
new file mode 100644
index 000000000000..52cc62d1c83b
--- /dev/null
+++ b/Documentation/dev-tools/kunit/running_tips.rst
@@ -0,0 +1,260 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+============================
+Tips For Running KUnit Tests
+============================
+
+Using ``kunit.py run`` ("kunit tool")
+=====================================
+
+Running from any directory
+--------------------------
+
+It can be handy to create a bash function like:
+
+.. code-block:: bash
+
+ function run_kunit() {
+ ( cd "$(git rev-parse --show-toplevel)" && ./tools/testing/kunit/kunit.py run $@ )
+ }
+
+.. note::
+ Early versions of ``kunit.py`` (before 5.6) didn't work unless run from
+ the kernel root, hence the use of a subshell and ``cd``.
+
+Running a subset of tests
+-------------------------
+
+``kunit.py run`` accepts an optional glob argument to filter tests. Currently
+this only matches against suite names, but this may change in the future.
+
+Say that we wanted to run the sysctl tests, we could do so via:
+
+.. code-block:: bash
+
+ $ echo -e 'CONFIG_KUNIT=y\nCONFIG_KUNIT_ALL_TESTS=y' > .kunit/.kunitconfig
+ $ ./tools/testing/kunit/kunit.py run 'sysctl*'
+
+We're paying the cost of building more tests than we need this way, but it's
+easier than fiddling with ``.kunitconfig`` files or commenting out
+``kunit_suite``'s.
+
+However, if we wanted to define a set of tests in a less ad hoc way, the next
+tip is useful.
+
+Defining a set of tests
+-----------------------
+
+``kunit.py run`` (along with ``build``, and ``config``) supports a
+``--kunitconfig`` flag. So if you have a set of tests that you want to run on a
+regular basis (especially if they have other dependencies), you can create a
+specific ``.kunitconfig`` for them.
+
+E.g. kunit has one for its tests:
+
+.. code-block:: bash
+
+ $ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit/.kunitconfig
+
+Alternatively, if you're following the convention of naming your
+file ``.kunitconfig``, you can just pass in the dir, e.g.
+
+.. code-block:: bash
+
+ $ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit
+
+.. note::
+ This is a relatively new feature (5.12+) so we don't have any
+ conventions yet about on what files should be checked in versus just
+ kept around locally. It's up to you and your maintainer to decide if a
+ config is useful enough to submit (and therefore have to maintain).
+
+.. note::
+ Having ``.kunitconfig`` fragments in a parent and child directory is
+ iffy. There's discussion about adding an "import" statement in these
+ files to make it possible to have a top-level config run tests from all
+ child directories. But that would mean ``.kunitconfig`` files are no
+ longer just simple .config fragments.
+
+ One alternative would be to have kunit tool recursively combine configs
+ automagically, but tests could theoretically depend on incompatible
+ options, so handling that would be tricky.
+
+Generating code coverage reports under UML
+------------------------------------------
+
+.. note::
+ TODO(brendanhiggins(a)google.com): There are various issues with UML and
+ versions of gcc 7 and up. You're likely to run into missing ``.gcda``
+ files or compile errors. We know one `faulty GCC commit
+ <https://github.com/gcc-mirror/gcc/commit/8c9434c2f9358b8b8bad2c1990edf10a21…>`_
+ but not how we'd go about getting this fixed. The compile errors still
+ need some investigation.
+
+.. note::
+ TODO(brendanhiggins(a)google.com): for recent versions of Linux
+ (5.10-5.12, maybe earlier), there's a bug with gcov counters not being
+ flushed in UML. This translates to very low (<1%) reported coverage. This is
+ related to the above issue and can be worked around by replacing the
+ one call to ``uml_abort()`` with a plain ``exit()``.
+
+
+This is different from the "normal" way of getting coverage information that is
+documented in Documentation/dev-tools/gcov.rst.
+
+Instead of enabling ``CONFIG_GCOV_KERNEL=y``, we can set these options:
+
+.. code-block:: none
+
+ CONFIG_DEBUG_KERNEL=y
+ CONFIG_DEBUG_INFO=y
+ CONFIG_GCOV=y
+
+
+Putting it together into a copy-pastable sequence of commands:
+
+.. code-block:: bash
+
+ # Append coverage options to the current config
+ $ echo -e "CONFIG_DEBUG_KERNEL=y\nCONFIG_DEBUG_INFO=y\nCONFIG_GCOV=y" >> .kunit/.kunitconfig
+ $ ./tools/testing/kunit/kunit.py run
+ # Extract the coverage information from the build dir (.kunit/)
+ $ lcov -t "my_kunit_tests" -o coverage.info -c -d .kunit/
+
+ # From here on, it's the same process as with CONFIG_GCOV_KERNEL=y
+ # E.g. can generate an HTML report in a tmp dir like so:
+ $ genhtml -o /tmp/coverage_html coverage.info
+
+
+If your installed version of gcc doesn't work, you can tweak the steps:
+
+.. code-block:: bash
+
+ # need to edit tools/testing/kunit/kunit_kernel.py to call make with 'CC=/usr/bin/gcc-6'
+ $ $EDITOR tools/testing/kunit/kunit_kernel.py
+
+ $ lcov -t "my_kunit_tests" -o coverage.info -c -d .kunit/ --gcov-tool=/usr/bin/gcov-6
+
+
+Running tests manually
+======================
+
+Running tests without using ``kunit.py run`` is also an important use case.
+Currently it's your only option if you want to test on architectures other than
+UML.
+
+As running the tests under UML is fairly straightforward (configure and compile
+the kernel, run the ``./linux`` binary), this section will focus on testing
+non-UML architectures.
+
+
+Running built-in tests
+----------------------
+
+When setting tests to ``=y``, the tests will run as part of boot and print
+results to dmesg in TAP format. So you just need to add your tests to your
+``.config``, build and boot your kernel as normal.
+
+So if we compiled our kernel with:
+
+.. code-block:: none
+
+ CONFIG_KUNIT=y
+ CONFIG_KUNIT_EXAMPLE_TEST=y
+
+Then we'd see output like this in dmesg signaling the test ran and passed:
+
+.. code-block:: none
+
+ TAP version 14
+ 1..1
+ # Subtest: example
+ 1..1
+ # example_simple_test: initializing
+ ok 1 - example_simple_test
+ ok 1 - example
+
+Running tests as modules
+------------------------
+
+Depending on the tests, you can build them as loadable modules.
+
+For example, we'd change the config options from before to
+
+.. code-block:: none
+
+ CONFIG_KUNIT=y
+ CONFIG_KUNIT_EXAMPLE_TEST=m
+
+Then after booting into our kernel, we can run the test via
+
+.. code-block:: none
+
+ $ modprobe kunit-example-test
+
+This will then cause it to print TAP output to stdout.
+
+.. note::
+ The ``modprobe`` will *not* have a non-zero exit code if any test
+ failed (as of 5.13). But ``kunit.py parse`` would, see below.
+
+.. note::
+ You can set ``CONFIG_KUNIT=m`` as well, however, some features will not
+ work and thus some tests might break. Ideally tests would specify they
+ depend on ``KUNIT=y`` in their ``Kconfig``'s, but this is an edge case
+ most test authors won't think about.
+ As of 5.13, the only difference is that ``current->kunit_test`` will
+ not exist.
+
+Pretty-printing results
+-----------------------
+
+You can use ``kunit.py parse`` to parse dmesg for test output and print out
+results in the same familiar format that ``kunit.py run`` does.
+
+.. code-block:: bash
+
+ $ ./tools/testing/kunit/kunit.py parse /var/log/dmesg
+
+
+Retrieving per suite results
+----------------------------
+
+Regardless of how you're running your tests, you can enable
+``CONFIG_KUNIT_DEBUGFS`` to expose per-suite TAP-formatted results:
+
+.. code-block:: none
+
+ CONFIG_KUNIT=y
+ CONFIG_KUNIT_EXAMPLE_TEST=m
+ CONFIG_KUNIT_DEBUGFS=y
+
+The results for each suite will be exposed under
+``/sys/kernel/debug/kunit/<suite>/results``.
+So using our example config:
+
+.. code-block:: bash
+
+ $ modprobe kunit-example-test > /dev/null
+ $ cat /sys/kernel/debug/kunit/example/results
+ ... <TAP output> ...
+
+ # After removing the module, the corresponding files will go away
+ $ modprobe -r kunit-example-test
+ $ cat /sys/kernel/debug/kunit/example/results
+ /sys/kernel/debug/kunit/example/results: No such file or directory
+
+Generating code coverage reports
+--------------------------------
+
+See Documentation/dev-tools/gcov.rst for details on how to do this.
+
+The only vaguely KUnit-specific advice here is that you probably want to build
+your tests as modules. That way you can isolate the coverage from tests from
+other code executed during boot, e.g.
+
+.. code-block:: bash
+
+ # Reset coverage counters before running the test.
+ $ echo 0 > /sys/kernel/debug/gcov/reset
+ $ modprobe kunit-example-test
diff --git a/Documentation/dev-tools/kunit/start.rst b/Documentation/dev-tools/kunit/start.rst
index 0e65cabe08eb..aa56d7ca6bfb 100644
--- a/Documentation/dev-tools/kunit/start.rst
+++ b/Documentation/dev-tools/kunit/start.rst
@@ -236,5 +236,7 @@ Next Steps
==========
* Check out the :doc:`tips` page for tips on
writing idiomatic KUnit tests.
+* Check out the :doc:`running_tips` page for tips on
+ how to make running KUnit tests easier.
* Optional: see the :doc:`usage` page for a more
in-depth explanation of KUnit.
base-commit: de2fcb3e62013738f22bbb42cbd757d9a242574e
--
2.31.1.295.g9ea45b61b8-goog
This is long overdue.
There are several things that aren't nailed down (in-tree
.kunitconfig's), or partially broken (GCOV on UML), but having them
documented, warts and all, is better than having nothing.
This covers a bunch of the more recent features
* kunit_filter_glob
* kunit.py run --kunitconfig
* kunit.py run --alltests
* slightly more detail on building tests as modules
* CONFIG_KUNIT_DEBUGFS
By my count, the only headline features now not mentioned are the KASAN
integration and KernelCI json output support (kunit.py run --json).
And then it also discusses how to get code coverage reports under UML
and non-UML since this is a question people have repeatedly asked.
Non-UML coverage collection is no differnt from normal, but we should
probably explicitly call thsi out.
As for UML, I was able to get it working again with two small hacks.*
E.g. with CONFIG_KUNIT=y && CONFIG_KUNIT_ALL_TESTS=y
Overall coverage rate:
lines......: 15.1% (18294 of 120776 lines)
functions..: 16.8% (1860 of 11050 functions)
*Switching to use gcc/gcov-6 and not using uml_abort().
I've documented these hacks in "Notes" but left TODOs for
brendanhiggins(a)google.com who tracked down the runtime issue in GCC.
To be clear: these are not issues specific to KUnit, but rather to UML.
Signed-off-by: Daniel Latypov <dlatypov(a)google.com>
---
Documentation/dev-tools/kunit/index.rst | 1 +
.../dev-tools/kunit/running_tips.rst | 278 ++++++++++++++++++
Documentation/dev-tools/kunit/start.rst | 2 +
3 files changed, 281 insertions(+)
create mode 100644 Documentation/dev-tools/kunit/running_tips.rst
diff --git a/Documentation/dev-tools/kunit/index.rst b/Documentation/dev-tools/kunit/index.rst
index 848478838347..7f7cf8d2ab20 100644
--- a/Documentation/dev-tools/kunit/index.rst
+++ b/Documentation/dev-tools/kunit/index.rst
@@ -14,6 +14,7 @@ KUnit - Unit Testing for the Linux Kernel
style
faq
tips
+ running_tips
What is KUnit?
==============
diff --git a/Documentation/dev-tools/kunit/running_tips.rst b/Documentation/dev-tools/kunit/running_tips.rst
new file mode 100644
index 000000000000..d38e665e530f
--- /dev/null
+++ b/Documentation/dev-tools/kunit/running_tips.rst
@@ -0,0 +1,278 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+============================
+Tips For Running KUnit Tests
+============================
+
+Using ``kunit.py run`` ("kunit tool")
+=====================================
+
+Running from any directory
+--------------------------
+
+It can be handy to create a bash function like:
+
+.. code-block:: bash
+
+ function run_kunit() {
+ ( cd "$(git rev-parse --show-toplevel)" && ./tools/testing/kunit/kunit.py run $@ )
+ }
+
+.. note::
+ Early versions of ``kunit.py`` (before 5.6) didn't work unless run from
+ the kernel root, hence the use of a subshell and ``cd``.
+
+Running a subset of tests
+-------------------------
+
+``kunit.py run`` accepts an optional glob argument to filter tests. Currently
+this only matches against suite names, but this may change in the future.
+
+Say that we wanted to run the sysctl tests, we could do so via:
+
+.. code-block:: bash
+
+ $ echo -e 'CONFIG_KUNIT=y\nCONFIG_KUNIT_ALL_TESTS=y' > .kunit/.kunitconfig
+ $ ./tools/testing/kunit/kunit.py run 'sysctl*'
+
+We're paying the cost of building more tests than we need this way, but it's
+easier than fiddling with ``.kunitconfig`` files or commenting out
+``kunit_suite``'s.
+
+However, if we wanted to define a set of tests in a less ad hoc way, the next
+tip is useful.
+
+Defining a set of tests
+-----------------------
+
+``kunit.py run`` (along with ``build``, and ``config``) supports a
+``--kunitconfig`` flag. So if you have a set of tests that you want to run on a
+regular basis (especially if they have other dependencies), you can create a
+specific ``.kunitconfig`` for them.
+
+E.g. kunit has own for its tests:
+
+.. code-block:: bash
+
+ $ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit/.kunitconfig
+
+Alternatively, if you're following the convention of naming your
+file ``.kunitconfig``, you can just pass in the dir, e.g.
+
+.. code-block:: bash
+
+ $ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit
+
+.. note::
+ This is a relatively new feature (5.12+) so we don't have any
+ conventions yet about on what files should be checked in versus just
+ kept around locally. But if the tests don't have any dependencies
+ (beyond ``CONFIG_KUNIT``), it's probably not worth writing and
+ maintaining a ``.kunitconfig`` fragment. Running with
+ ``CONFIG_KUNIT_ALL_TESTS=y`` is probably easier.
+
+.. note::
+ Having ``.kunitconfig`` fragments in a parent and child directory is
+ iffy. There's discussion about adding an "import" statement in these
+ files to make it possible to have a top-level config run tests from all
+ child directories. But that would mean ``.kunitconfig`` files are no
+ longer just simple .config fragments.
+
+ One alternative would be to have kunit tool recursively combine configs
+ automagically, but tests could theoretically depend on incompatible
+ options, so handling that would be tricky.
+
+Running with ``allyesconfig``
+-----------------------------
+
+.. code-block:: bash
+
+ $ ./tools/testing/kunit/kunit.py run --alltests
+
+This will try and use ``allyesconfig``, or rather ``allyesconfig`` with a list
+of UML-incompatible configs turned off. That list is maintained in
+``tools/testing/kunit/configs/broken_on_uml.config``.
+
+.. note::
+ This will take a *lot* longer to run and might be broken from time to
+ time, especially on -next. It's not recommended to use this unless you
+ need to or are morbidly curious.
+
+Generating code coverage reports under UML
+------------------------------------------
+
+.. note::
+ TODO(brendanhiggins(a)google.com): There are various issues with UML and
+ versions of gcc 7 and up. You're likely to run into missing ``.gcda``
+ files or compile errors. We know one `faulty GCC commit
+ <https://github.com/gcc-mirror/gcc/commit/8c9434c2f9358b8b8bad2c1990edf10a21…>`_
+ but not how we'd go about getting this fixed. The compile errors still
+ need some investigation.
+
+.. note::
+ TODO(brendanhiggins(a)google.com): for recent versions of Linux
+ (5.10-5.12, maybe earlier), there's a bug with gcov counters not being
+ flushed in UML. This translates to very low (<1%) reported coverage. This is
+ related to the above issue and can be worked around by replacing the
+ one call to ``uml_abort()`` with a plain ``exit()``.
+
+
+This is different from the "normal" way of getting coverage information that is
+documented in Documentation/dev-tools/gcov.rst.
+
+Instead of enabling ``CONFIG_GCOV_KERNEL=y``, we can set these options:
+
+.. code-block:: none
+
+ CONFIG_DEBUG_KERNEL=y
+ CONFIG_DEBUG_INFO=y
+ CONFIG_GCOV=y
+
+
+Putting it together into a copy-pastable sequence of commands:
+
+.. code-block:: bash
+
+ # Append coverage options to the current config
+ $ echo -e "CONFIG_DEBUG_KERNEL=y\nCONFIG_DEBUG_INFO=y\nCONFIG_GCOV=y" >> .kunit/.kunitconfig
+ $ ./tools/testing/kunit/kunit.py run
+ # Extract the coverage information from the build dir (.kunit/)
+ $ lcov -t "my_kunit_tests" -o coverage.info -c -d .kunit/
+
+ # From here on, it's the same process as with CONFIG_GCOV_KERNEL=y
+ # E.g. can generate an HTML report in a tmp dir like so:
+ $ genhtml -o /tmp/coverage_html coverage.info
+
+
+If your installed version of gcc doesn't work, you can tweak the steps:
+
+.. code-block:: bash
+
+ # need to edit tools/testing/kunit/kunit_kernel.py to call make with 'CC=/usr/bin/gcc-6'
+ $ $EDITOR tools/testing/kunit/kunit_kernel.py
+
+ $ lcov -t "my_kunit_tests" -o coverage.info -c -d .kunit/ --gcov-tool=/usr/bin/gcov-6
+
+
+Running tests manually
+======================
+
+Running tests without using ``kunit.py run`` is also an important use case.
+Currently it's your only option if you want to test on architectures other than
+UML.
+
+As running the tests under UML is fairly straightforward (configure and compile
+the kernel, run the ``./linux`` binary), this section will focus on testing
+non-UML architectures.
+
+
+Running built-in tests
+----------------------
+
+When setting tests to ``=y``, the tests will run as part of boot and print
+results to dmesg in TAP format. So you just need to add your tests to your
+``.config``, build and boot your kernel as normal.
+
+So if we compiled our kernel with:
+
+.. code-block:: none
+
+ CONFIG_KUNIT=y
+ CONFIG_KUNIT_EXAMPLE_TEST=y
+
+Then we'd see output like this in dmesg signaling the test ran and passed:
+
+.. code-block:: none
+
+ TAP version 14
+ 1..1
+ # Subtest: example
+ 1..1
+ # example_simple_test: initializing
+ ok 1 - example_simple_test
+ ok 1 - example
+
+Running tests as modules
+------------------------
+
+Depending on the tests, you can build them as loadable modules.
+
+For example, we'd change the config options from before to
+
+.. code-block:: none
+
+ CONFIG_KUNIT=y
+ CONFIG_KUNIT_EXAMPLE_TEST=m
+
+Then after booting into our kernel, we can run the test via
+
+.. code-block:: none
+
+ $ modprobe kunit-example-test
+
+This will then cause it to print TAP output to stdout.
+
+.. note::
+ The ``modprobe`` will *not* have a non-zero exit code if any test
+ failed (as of 5.13). But ``kunit.py parse`` would, see below.
+
+.. note::
+ You can set ``CONFIG_KUNIT=m`` as well, however, some features will not
+ work and thus some tests might break. Ideally tests would specify they
+ depend on ``KUNIT=y`` in their ``Kconfig``'s, but this is an edge case
+ most test authors won't think about.
+ As of 5.13, the only difference is that ``current->kunit_test`` will
+ not exist.
+
+Pretty-printing results
+-----------------------
+
+You can use ``kunit.py parse`` to parse dmesg for test output and print out
+results in the same familiar format that ``kunit.py run`` does.
+
+.. code-block:: bash
+
+ $ ./tools/testing/kunit/kunit.py parse /var/log/dmesg
+
+
+Retrieving per suite results
+----------------------------
+
+Regardless of how you're running your tests, you can enable
+``CONFIG_KUNIT_DEBUGFS`` to expose per-suite TAP-formatted results:
+
+.. code-block:: none
+
+ CONFIG_KUNIT=y
+ CONFIG_KUNIT_EXAMPLE_TEST=m
+ CONFIG_KUNIT_DEBUGFS=y
+
+The results for each suite will be exposed under
+``/sys/kernel/debug/kunit/<suite>/results``.
+So using our example config:
+
+.. code-block:: bash
+
+ $ modprobe kunit-example-test > /dev/null
+ $ cat /sys/kernel/debug/kunit/example/results
+ ... <TAP output> ...
+
+ # After removing the module, the corresponding files will go away
+ $ modprobe -r kunit-example-test
+ $ cat /sys/kernel/debug/kunit/example/results
+ /sys/kernel/debug/kunit/example/results: No such file or directory
+
+Generating code coverage reports
+--------------------------------
+
+See Documentation/dev-tools/gcov.rst for details on how to do this.
+
+The only vaguely KUnit-specific advice here is that you probably want to build
+your tests as modules. That way you can isolate the coverage from tests from
+other code executed during boot, e.g.
+
+.. code-block:: bash
+
+ # Reset coverage counters before running the test.
+ $ echo 0 > /sys/kernel/debug/gcov/reset
+ $ modprobe kunit-example-test
diff --git a/Documentation/dev-tools/kunit/start.rst b/Documentation/dev-tools/kunit/start.rst
index 0e65cabe08eb..aa56d7ca6bfb 100644
--- a/Documentation/dev-tools/kunit/start.rst
+++ b/Documentation/dev-tools/kunit/start.rst
@@ -236,5 +236,7 @@ Next Steps
==========
* Check out the :doc:`tips` page for tips on
writing idiomatic KUnit tests.
+* Check out the :doc:`running_tips` page for tips on
+ how to make running KUnit tests easier.
* Optional: see the :doc:`usage` page for a more
in-depth explanation of KUnit.
base-commit: de2fcb3e62013738f22bbb42cbd757d9a242574e
--
2.31.1.295.g9ea45b61b8-goog
This patchset introduces batched operations for the per-cpu variant of
the array map.
It also removes the percpu macros from 'bpf_util.h'. This change was
suggested by Andrii in a earlier iteration of this patchset.
The tests were updated to reflect all the new changes.
v2 -> v3:
- Remove percpu macros as suggested by Andrii
- Update tests that used the per cpu macros
v1 -> v2:
- Amended a more descriptive commit message
Pedro Tammela (3):
bpf: add batched ops support for percpu array
bpf: selftests: remove percpu macros from bpf_util.h
bpf: selftests: update array map tests for per-cpu batched ops
kernel/bpf/arraymap.c | 2 +
tools/testing/selftests/bpf/bpf_util.h | 7 --
.../bpf/map_tests/array_map_batch_ops.c | 110 +++++++++++++-----
.../bpf/map_tests/htab_map_batch_ops.c | 71 ++++++-----
.../selftests/bpf/prog_tests/map_init.c | 9 +-
tools/testing/selftests/bpf/test_maps.c | 84 +++++++------
6 files changed, 171 insertions(+), 112 deletions(-)
--
2.25.1
The kernel now has a number of testing and debugging tools, and we've
seen a bit of confusion about what the differences between them are.
Add a basic documentation outlining the testing tools, when to use each,
and how they interact.
This is a pretty quick overview rather than the idealised "kernel
testing guide" that'd probably be optimal, but given the number of times
questions like "When do you use KUnit and when do you use Kselftest?"
are being asked, it seemed worth at least having something. Hopefully
this can form the basis for more detailed documentation later.
Signed-off-by: David Gow <davidgow(a)google.com>
---
Documentation/dev-tools/index.rst | 3 +
Documentation/dev-tools/testing-overview.rst | 102 +++++++++++++++++++
2 files changed, 105 insertions(+)
create mode 100644 Documentation/dev-tools/testing-overview.rst
diff --git a/Documentation/dev-tools/index.rst b/Documentation/dev-tools/index.rst
index 1b1cf4f5c9d9..f590e5860794 100644
--- a/Documentation/dev-tools/index.rst
+++ b/Documentation/dev-tools/index.rst
@@ -7,6 +7,8 @@ be used to work on the kernel. For now, the documents have been pulled
together without any significant effort to integrate them into a coherent
whole; patches welcome!
+A brief overview of testing-specific tools can be found in :doc:`testing-overview`.
+
.. class:: toc-title
Table of contents
@@ -14,6 +16,7 @@ whole; patches welcome!
.. toctree::
:maxdepth: 2
+ testing-overview
coccinelle
sparse
kcov
diff --git a/Documentation/dev-tools/testing-overview.rst b/Documentation/dev-tools/testing-overview.rst
new file mode 100644
index 000000000000..8452adcb8608
--- /dev/null
+++ b/Documentation/dev-tools/testing-overview.rst
@@ -0,0 +1,102 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+====================
+Kernel Testing Guide
+====================
+
+
+There are a number of different tools for testing the Linux kernel, so knowing
+when to use each of them can be a challenge. This document provides a rough
+overview of their differences, and how they fit together.
+
+
+Writing and Running Tests
+=========================
+
+The bulk of kernel tests are written using either the :doc:`kselftest
+<kselftest>` or :doc:`KUnit <kunit/index>` frameworks. These both provide
+infrastructure to help make running tests and groups of tests easier, as well
+as providing helpers to aid in writing new tests.
+
+If you're looking to verify the behaviour of the Kernel — particularly specific
+parts of the kernel — then you'll want to use `KUnit` or `kselftest`.
+
+
+The Difference Between KUnit and kselftest
+------------------------------------------
+
+:doc:`KUnit <kunit/index>` is an entirely in-kernel system for "white box"
+testing: because test code is part of the kernel, it can access internal
+structures and functions which aren't exposed to userspace.
+
+`KUnit` tests therefore are best written against small, self-contained parts
+of the kernel, which can be tested in isolation. This aligns well with the
+concept of Unit testing.
+
+For example, a KUnit test might test an individual kernel function (or even a
+single codepath through a function, such as an error handling case), rather
+than a feature as a whole.
+
+There is a KUnit test style guide which may give further pointers
+
+
+:doc:`kselftest <kselftest>`, on the other hand, is largely implemented in
+userspace, and tests are normal userspace scripts or programs.
+
+This makes it easier to write more complicated tests, or tests which need to
+manipulate the overall system state more (e.g., spawning processes, etc.).
+However, it's not possible to call kernel functions directly unless they're
+exposed to userspace (by a syscall, device, filesystem, etc.) Some tests to
+also provide a kernel module which is loaded by the test, though for tests
+which run mostly or entirely within the kernel, `KUnit` may be the better tool.
+
+`kselftest` is therefore suited well to tests of whole features, as these will
+expose an interface to userspace, which can be tested, but not implementation
+details. This aligns well with 'system' or 'end-to-end' testing.
+
+
+Code Coverage Tools
+===================
+
+The Linux Kernel supports two different code coverage mesurement tools. These
+can be used to verify that a test is executing particular functions or lines
+of code. This is useful for determining how much of the kernel is being tested,
+and for finding corner-cases which are not covered by the appropriate test.
+
+:doc:`kcov` is a feature which can be built in to the kernel to allow
+capturing coverage on a per-task level. It's therefore useful for fuzzing and
+other situations where information about code executed during, for example, a
+single syscall is useful.
+
+:doc:`gcov` is GCC's coverage testing tool, which can be used with the kernel
+to get global or per-module coverage. Unlike KCOV, it does not record per-task
+coverage. Coverage data can be read from debugfs, and interpreted using the
+usual gcov tooling.
+
+
+Sanitizers
+==========
+
+The kernel also supports a number of sanitizers, which attempt to detect
+classes of issues when the occur in a running kernel. These typically
+look for undefined behaviour of some kind, such as invalid memory accesses,
+concurrency issues such as data races, or other undefined behaviour like
+integer overflows.
+
+* :doc:`kmemleak` (Kmemleak) detects possible memory leaks.
+* :doc:`kasan` detects invalid memory accesses such as out-of-bounds and
+ use-after-free errors.
+* :doc:`ubsan` detects behaviour that is undefined by the C standard, like
+ integer overflows.
+* :doc:`kcsan` detects data races.
+* :doc:`kfence` is a low-overhead detector of memory issues, which is much
+ faster than KASAN and can be used in production.
+
+These tools tend to test the kernel as a whole, and do not "pass" like
+kselftest or KUnit tests. They can be combined with KUnit or kselftest by
+running tests on a kernel with a sanitizer enabled: you can then be sure
+that none of these errors are occurring during the test.
+
+Some of these sanitizers integrate with KUnit or kselftest and will
+automatically fail tests if an issue is detected by a sanitizer.
+
--
2.31.1.295.g9ea45b61b8-goog
Changelog
RFC v2-->v3
Based on comments by Doug Smythies,
1. Changed commit log to reflect the test must be run as super user.
2. Added a comment specifying a method to run the test bash script
without recompiling.
3. Enable all the idle states after the experiments are completed so
that the system is in a coherent state after the tests have run
4. Correct the return status of a CPU that cannot be off-lined.
RFC v2: https://lkml.org/lkml/2021/4/1/615
---
A kernel module + userspace driver to estimate the wakeup latency
caused by going into stop states. The motivation behind this program is
to find significant deviations behind advertised latency and residency
values.
The patchset measures latencies for two kinds of events. IPIs and Timers
As this is a software-only mechanism, there will additional latencies of
the kernel-firmware-hardware interactions. To account for that, the
program also measures a baseline latency on a 100 percent loaded CPU
and the latencies achieved must be in view relative to that.
To achieve this, we introduce a kernel module and expose its control
knobs through the debugfs interface that the selftests can engage with.
The kernel module provides the following interfaces within
/sys/kernel/debug/latency_test/ for,
IPI test:
ipi_cpu_dest = Destination CPU for the IPI
ipi_cpu_src = Origin of the IPI
ipi_latency_ns = Measured latency time in ns
Timeout test:
timeout_cpu_src = CPU on which the timer to be queued
timeout_expected_ns = Timer duration
timeout_diff_ns = Difference of actual duration vs expected timer
Sample output on a POWER9 system is as follows:
# --IPI Latency Test---
# Baseline Average IPI latency(ns): 3114
# Observed Average IPI latency(ns) - State0: 3265
# Observed Average IPI latency(ns) - State1: 3507
# Observed Average IPI latency(ns) - State2: 3739
# Observed Average IPI latency(ns) - State3: 3807
# Observed Average IPI latency(ns) - State4: 17070
# Observed Average IPI latency(ns) - State5: 1038174
# Observed Average IPI latency(ns) - State6: 1068784
#
# --Timeout Latency Test--
# Baseline Average timeout diff(ns): 1420
# Observed Average timeout diff(ns) - State0: 1640
# Observed Average timeout diff(ns) - State1: 1764
# Observed Average timeout diff(ns) - State2: 1715
# Observed Average timeout diff(ns) - State3: 1845
# Observed Average timeout diff(ns) - State4: 16581
# Observed Average timeout diff(ns) - State5: 939977
# Observed Average timeout diff(ns) - State6: 1073024
Things to keep in mind:
1. This kernel module + bash driver does not guarantee idleness on a
core when the IPI and the Timer is armed. It only invokes sleep and
hopes that the core is idle once the IPI/Timer is invoked onto it.
Hence this program must be run on a completely idle system for best
results
2. Even on a completely idle system, there maybe book-keeping tasks or
jitter tasks that can run on the core we want idle. This can create
outliers in the latency measurement. Thankfully, these outliers
should be large enough to easily weed them out.
3. A userspace only selftest variant was also sent out as RFC based on
suggestions over the previous patchset to simply the kernel
complexeity. However, a userspace only approach had more noise in
the latency measurement due to userspace-kernel interactions
which led to run to run variance and a lesser accurate test.
Another downside of the nature of a userspace program is that it
takes orders of magnitude longer to complete a full system test
compared to the kernel framework.
RFC patch: https://lkml.org/lkml/2020/9/2/356
4. For Intel Systems, the Timer based latencies don't exactly give out
the measure of idle latencies. This is because of a hardware
optimization mechanism that pre-arms a CPU when a timer is set to
wakeup. That doesn't make this metric useless for Intel systems,
it just means that is measuring IPI/Timer responding latency rather
than idle wakeup latencies.
(Source: https://lkml.org/lkml/2020/9/2/610)
For solution to this problem, a hardware based latency analyzer is
devised by Artem Bityutskiy from Intel.
https://youtu.be/Opk92aQyvt0?t=8266https://intel.github.io/wult/
Pratik Rajesh Sampat (2):
cpuidle: Extract IPI based and timer based wakeup latency from idle
states
selftest/cpuidle: Add support for cpuidle latency measurement
drivers/cpuidle/Makefile | 1 +
drivers/cpuidle/test-cpuidle_latency.c | 157 ++++++++++
lib/Kconfig.debug | 10 +
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/cpuidle/Makefile | 6 +
tools/testing/selftests/cpuidle/cpuidle.sh | 326 +++++++++++++++++++++
tools/testing/selftests/cpuidle/settings | 2 +
7 files changed, 503 insertions(+)
create mode 100644 drivers/cpuidle/test-cpuidle_latency.c
create mode 100644 tools/testing/selftests/cpuidle/Makefile
create mode 100755 tools/testing/selftests/cpuidle/cpuidle.sh
create mode 100644 tools/testing/selftests/cpuidle/settings
--
2.17.1
This series aims to clarify the behavior of the KVM_GET_EMULATED_CPUID
ioctl, and fix a corner case where -E2BIG is returned when
the nent field of struct kvm_cpuid2 is matching the amount of
emulated entries that kvm returns.
Patch 1 proposes the nent field fix to cpuid.c,
patch 2 updates the ioctl documentation accordingly and
patches 3 and 4 extend the x86_64/get_cpuid_test.c selftest to check
the intended behavior of KVM_GET_EMULATED_CPUID.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit(a)redhat.com>
---
v5:
- Better comment in cpuid.c (patch 1)
Emanuele Giuseppe Esposito (4):
KVM: x86: Fix a spurious -E2BIG in KVM_GET_EMULATED_CPUID
Documentation: KVM: update KVM_GET_EMULATED_CPUID ioctl description
selftests: add kvm_get_emulated_cpuid to processor.h
selftests: KVM: extend get_cpuid_test to include
KVM_GET_EMULATED_CPUID
Documentation/virt/kvm/api.rst | 10 +--
arch/x86/kvm/cpuid.c | 33 ++++---
.../selftests/kvm/include/x86_64/processor.h | 1 +
.../selftests/kvm/lib/x86_64/processor.c | 33 +++++++
.../selftests/kvm/x86_64/get_cpuid_test.c | 90 ++++++++++++++++++-
5 files changed, 142 insertions(+), 25 deletions(-)
--
2.30.2
This series aims to clarify the behavior of the KVM_GET_EMULATED_CPUID
ioctl, and fix a corner case where -E2BIG is returned when
the nent field of struct kvm_cpuid2 is matching the amount of
emulated entries that kvm returns.
Patch 1 proposes the nent field fix to cpuid.c,
patch 2 updates the ioctl documentation accordingly and
patches 3 and 4 extend the x86_64/get_cpuid_test.c selftest to check
the intended behavior of KVM_GET_EMULATED_CPUID.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit(a)redhat.com>
---
v4:
- Address nitpicks given in the mailing list
Emanuele Giuseppe Esposito (4):
KVM: x86: Fix a spurious -E2BIG in KVM_GET_EMULATED_CPUID
Documentation: KVM: update KVM_GET_EMULATED_CPUID ioctl description
selftests: add kvm_get_emulated_cpuid to processor.h
selftests: KVM: extend get_cpuid_test to include
KVM_GET_EMULATED_CPUID
Documentation/virt/kvm/api.rst | 10 +--
arch/x86/kvm/cpuid.c | 33 ++++---
.../selftests/kvm/include/x86_64/processor.h | 1 +
.../selftests/kvm/lib/x86_64/processor.c | 33 +++++++
.../selftests/kvm/x86_64/get_cpuid_test.c | 90 ++++++++++++++++++-
5 files changed, 142 insertions(+), 25 deletions(-)
--
2.30.2
As of commit 359a376081d4 ("kunit: support failure from dynamic analysis
tools"), we can use current->kunit_test to find the current kunit test.
Mention this in tips.rst and give an example of how this can be used in
conjunction with `test->priv` to pass around state and specifically
implement something like mocking.
There's a lot more we could go into on that topic, but given that
example is already longer than every other "tip" on this page, we just
point to the API docs and leave filling in the blanks as an exercise to
the reader.
Also give an example of kunit_fail_current_test().
Signed-off-by: Daniel Latypov <dlatypov(a)google.com>
---
Documentation/dev-tools/kunit/tips.rst | 78 +++++++++++++++++++++++++-
1 file changed, 76 insertions(+), 2 deletions(-)
diff --git a/Documentation/dev-tools/kunit/tips.rst b/Documentation/dev-tools/kunit/tips.rst
index a6ca0af14098..8d8c238f7f79 100644
--- a/Documentation/dev-tools/kunit/tips.rst
+++ b/Documentation/dev-tools/kunit/tips.rst
@@ -78,8 +78,82 @@ Similarly to the above, it can be useful to add test-specific logic.
void test_only_hook(void) { }
#endif
-TODO(dlatypov(a)google.com): add an example of using ``current->kunit_test`` in
-such a hook when it's not only updated for ``CONFIG_KASAN=y``.
+This test-only code can be made more useful by accessing the current kunit
+test, see below.
+
+Accessing the current test
+--------------------------
+
+In some cases, you need to call test-only code from outside the test file, e.g.
+like in the example above or if you're providing a fake implementation of an
+ops struct.
+There is a ``kunit_test`` field in ``task_struct``, so you can access it via
+``current->kunit_test``.
+
+Here's a slightly in-depth example of how one could implement "mocking":
+
+.. code-block:: c
+
+ #include <linux/sched.h> /* for current */
+
+ struct test_data {
+ int foo_result;
+ int want_foo_called_with;
+ };
+
+ static int fake_foo(int arg)
+ {
+ struct kunit *test = current->kunit_test;
+ struct test_data *test_data = test->priv;
+
+ KUNIT_EXPECT_EQ(test, test_data->want_foo_called_with, arg);
+ return test_data->foo_result;
+ }
+
+ static void example_simple_test(struct kunit *test)
+ {
+ /* Assume priv is allocated in the suite's .init */
+ struct test_data *test_data = test->priv;
+
+ test_data->foo_result = 42;
+ test_data->want_foo_called_with = 1;
+
+ /* In a real test, we'd probably pass a pointer to fake_foo somewhere
+ * like an ops struct, etc. instead of calling it directly. */
+ KUNIT_EXPECT_EQ(test, fake_foo(1), 42);
+ }
+
+
+Note: here we're able to get away with using ``test->priv``, but if you wanted
+something more flexible you could use a named ``kunit_resource``, see :doc:`api/test`.
+
+Failing the current test
+------------------------
+
+But sometimes, you might just want to fail the current test. In that case, we
+have ``kunit_fail_current_test(fmt, args...)`` which is defined in ``<kunit/test-bug.h>`` and
+doesn't require pulling in ``<kunit/test.h>``.
+
+E.g. say we had an option to enable some extra debug checks on some data structure:
+
+.. code-block:: c
+
+ #include <kunit/test-bug.h>
+
+ #ifdef CONFIG_EXTRA_DEBUG_CHECKS
+ static void validate_my_data(struct data *data)
+ {
+ if (is_valid(data))
+ return;
+
+ kunit_fail_current_test("data %p is invalid", data);
+
+ /* Normal, non-KUnit, error reporting code here. */
+ }
+ #else
+ static void my_debug_function(void) { }
+ #endif
+
Customizing error messages
--------------------------
base-commit: 0a50438c84363bd37fe18fe432888ae9a074dcab
--
2.31.0.208.g409f899ff0-goog
This patchset introduces batched operations for the per-cpu variant of
the array map.
It also introduces a standard way to define per-cpu values via the
'BPF_PERCPU_TYPE()' macro, which handles the alignment transparently.
This was already implemented in the selftests and was merely refactored
out to libbpf, with some simplifications for reuse.
The tests were updated to reflect all the new changes.
v1 -> v2:
- Amended a more descriptive commit message
Pedro Tammela (3):
bpf: add batched ops support for percpu array
libbpf: selftests: refactor 'BPF_PERCPU_TYPE()' and 'bpf_percpu()'
macros
bpf: selftests: update array map tests for per-cpu batched ops
kernel/bpf/arraymap.c | 2 +
tools/lib/bpf/bpf.h | 10 ++
tools/testing/selftests/bpf/bpf_util.h | 7 --
.../bpf/map_tests/array_map_batch_ops.c | 114 +++++++++++++-----
.../bpf/map_tests/htab_map_batch_ops.c | 48 ++++----
.../selftests/bpf/prog_tests/map_init.c | 5 +-
tools/testing/selftests/bpf/test_maps.c | 16 +--
7 files changed, 133 insertions(+), 69 deletions(-)
--
2.25.1
This series aims to clarify the behavior of the KVM_GET_EMULATED_CPUID
ioctl, and fix a corner case where -E2BIG is returned when
the nent field of struct kvm_cpuid2 is matching the amount of
emulated entries that kvm returns.
Patch 1 proposes the nent field fix to cpuid.c,
patch 2 updates the ioctl documentation accordingly and
patches 3 and 4 extend the x86_64/get_cpuid_test.c selftest to check
the intended behavior of KVM_GET_EMULATED_CPUID.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit(a)redhat.com>
---
v3:
- clearer commit message and problem explanation
- pre-initialize the stack variable 'entry' in __do_cpuid_func_emulated
so that the various eax/ebx/ecx are initialized if not set by func.
Emanuele Giuseppe Esposito (4):
KVM: x86: Fix a spurious -E2BIG in KVM_GET_EMULATED_CPUID
Documentation: KVM: update KVM_GET_EMULATED_CPUID ioctl description
selftests: add kvm_get_emulated_cpuid to processor.h
selftests: KVM: extend get_cpuid_test to include
KVM_GET_EMULATED_CPUID
Documentation/virt/kvm/api.rst | 10 +--
arch/x86/kvm/cpuid.c | 33 ++++---
.../selftests/kvm/include/x86_64/processor.h | 1 +
.../selftests/kvm/lib/x86_64/processor.c | 33 +++++++
.../selftests/kvm/x86_64/get_cpuid_test.c | 90 ++++++++++++++++++-
5 files changed, 142 insertions(+), 25 deletions(-)
--
2.30.2
This patchset introduces batched operations for the per-cpu variant of
the array map.
It also introduces a standard way to define per-cpu values via the
'BPF_PERCPU_TYPE()' macro, which handles the alignment transparently.
This was already implemented in the selftests and was merely refactored
out to libbpf, with some simplifications for reuse.
The tests were updated to reflect all the new changes.
Pedro Tammela (3):
bpf: add batched ops support for percpu array
libbpf: selftests: refactor 'BPF_PERCPU_TYPE()' and 'bpf_percpu()'
macros
bpf: selftests: update array map tests for per-cpu batched ops
kernel/bpf/arraymap.c | 2 +
tools/lib/bpf/bpf.h | 10 ++
tools/testing/selftests/bpf/bpf_util.h | 7 --
.../bpf/map_tests/array_map_batch_ops.c | 114 +++++++++++++-----
.../bpf/map_tests/htab_map_batch_ops.c | 48 ++++----
.../selftests/bpf/prog_tests/map_init.c | 5 +-
tools/testing/selftests/bpf/test_maps.c | 16 +--
7 files changed, 133 insertions(+), 69 deletions(-)
--
2.25.1
Changelog
RFC v1-->v2
The timer based test produces run to run variance on some intel based
systems that sport a mechansim of "C-state pre-wake" which can
pre-wake a CPU from an idle state when timers are armed.
Hence invoking the timer tests is now parameterized for systems and
architectures that don't support pre-wakeup logic and need granular
timer measurements along with IPI results.
This RFC does not yet support treating of CPU 0s idle states differently
especially as reported on Intel systems. More understanding is needed
on systems to determine if only CPU 0 is treated differently of if they
are more CPUs that cannot have its idle state properties changed.
RFC v1: https://lkml.org/lkml/2021/3/15/492
---
A kernel module + userspace driver to estimate the wakeup latency
caused by going into stop states. The motivation behind this program is
to find significant deviations behind advertised latency and residency
values.
The patchset measures latencies for two kinds of events. IPIs and Timers
As this is a software-only mechanism, there will additional latencies of
the kernel-firmware-hardware interactions. To account for that, the
program also measures a baseline latency on a 100 percent loaded CPU
and the latencies achieved must be in view relative to that.
To achieve this, we introduce a kernel module and expose its control
knobs through the debugfs interface that the selftests can engage with.
The kernel module provides the following interfaces within
/sys/kernel/debug/latency_test/ for,
IPI test:
ipi_cpu_dest = Destination CPU for the IPI
ipi_cpu_src = Origin of the IPI
ipi_latency_ns = Measured latency time in ns
Timeout test:
timeout_cpu_src = CPU on which the timer to be queued
timeout_expected_ns = Timer duration
timeout_diff_ns = Difference of actual duration vs expected timer
Sample output on a POWER9 system is as follows:
# --IPI Latency Test---
# Baseline Average IPI latency(ns): 3114
# Observed Average IPI latency(ns) - State0: 3265
# Observed Average IPI latency(ns) - State1: 3507
# Observed Average IPI latency(ns) - State2: 3739
# Observed Average IPI latency(ns) - State3: 3807
# Observed Average IPI latency(ns) - State4: 17070
# Observed Average IPI latency(ns) - State5: 1038174
# Observed Average IPI latency(ns) - State6: 1068784
#
# --Timeout Latency Test--
# Baseline Average timeout diff(ns): 1420
# Observed Average timeout diff(ns) - State0: 1640
# Observed Average timeout diff(ns) - State1: 1764
# Observed Average timeout diff(ns) - State2: 1715
# Observed Average timeout diff(ns) - State3: 1845
# Observed Average timeout diff(ns) - State4: 16581
# Observed Average timeout diff(ns) - State5: 939977
# Observed Average timeout diff(ns) - State6: 1073024
Things to keep in mind:
1. This kernel module + bash driver does not guarantee idleness on a
core when the IPI and the Timer is armed. It only invokes sleep and
hopes that the core is idle once the IPI/Timer is invoked onto it.
Hence this program must be run on a completely idle system for best
results
2. Even on a completely idle system, there maybe book-keeping tasks or
jitter tasks that can run on the core we want idle. This can create
outliers in the latency measurement. Thankfully, these outliers
should be large enough to easily weed them out.
3. A userspace only selftest variant was also sent out as RFC based on
suggestions over the previous patchset to simply the kernel
complexeity. However, a userspace only approach had more noise in
the latency measurement due to userspace-kernel interactions
which led to run to run variance and a lesser accurate test.
Another downside of the nature of a userspace program is that it
takes orders of magnitude longer to complete a full system test
compared to the kernel framework.
RFC patch: https://lkml.org/lkml/2020/9/2/356
4. For Intel Systems, the Timer based latencies don't exactly give out
the measure of idle latencies. This is because of a hardware
optimization mechanism that pre-arms a CPU when a timer is set to
wakeup. That doesn't make this metric useless for Intel systems,
it just means that is measuring IPI/Timer responding latency rather
than idle wakeup latencies.
(Source: https://lkml.org/lkml/2020/9/2/610)
For solution to this problem, a hardware based latency analyzer is
devised by Artem Bityutskiy from Intel.
https://youtu.be/Opk92aQyvt0?t=8266https://intel.github.io/wult/
Pratik Rajesh Sampat (2):
cpuidle: Extract IPI based and timer based wakeup latency from idle
states
selftest/cpuidle: Add support for cpuidle latency measurement
drivers/cpuidle/Makefile | 1 +
drivers/cpuidle/test-cpuidle_latency.c | 157 ++++++++++
lib/Kconfig.debug | 10 +
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/cpuidle/Makefile | 6 +
tools/testing/selftests/cpuidle/cpuidle.sh | 323 +++++++++++++++++++++
tools/testing/selftests/cpuidle/settings | 2 +
7 files changed, 500 insertions(+)
create mode 100644 drivers/cpuidle/test-cpuidle_latency.c
create mode 100644 tools/testing/selftests/cpuidle/Makefile
create mode 100755 tools/testing/selftests/cpuidle/cpuidle.sh
create mode 100644 tools/testing/selftests/cpuidle/settings
--
2.17.1
This patchset provides a file descriptor for every VM and VCPU to read
KVM statistics data in binary format.
It is meant to provide a lightweight, flexible, scalable and efficient
lock-free solution for user space telemetry applications to pull the
statistics data periodically for large scale systems. The pulling
frequency could be as high as a few times per second.
In this patchset, every statistics data are treated to have some
attributes as below:
* architecture dependent or common
* VM statistics data or VCPU statistics data
* type: cumulative, instantaneous,
* unit: none for simple counter, nanosecond, microsecond,
millisecond, second, Byte, KiByte, MiByte, GiByte. Clock Cycles
Since no lock/synchronization is used, the consistency between all
the statistics data is not guaranteed. That means not all statistics
data are read out at the exact same time, since the statistics date
are still being updated by KVM subsystems while they are read out.
Jing Zhang (4):
KVM: stats: Separate common stats from architecture specific ones
KVM: stats: Add fd-based API to read binary stats data
KVM: stats: Add documentation for statistics data binary interface
KVM: selftests: Add selftest for KVM statistics data binary interface
Documentation/virt/kvm/api.rst | 169 ++++++++
arch/arm64/include/asm/kvm_host.h | 9 +-
arch/arm64/kvm/guest.c | 42 +-
arch/mips/include/asm/kvm_host.h | 9 +-
arch/mips/kvm/mips.c | 67 +++-
arch/powerpc/include/asm/kvm_host.h | 9 +-
arch/powerpc/kvm/book3s.c | 68 +++-
arch/powerpc/kvm/book3s_hv.c | 12 +-
arch/powerpc/kvm/book3s_pr.c | 2 +-
arch/powerpc/kvm/book3s_pr_papr.c | 2 +-
arch/powerpc/kvm/booke.c | 63 ++-
arch/s390/include/asm/kvm_host.h | 9 +-
arch/s390/kvm/kvm-s390.c | 133 ++++++-
arch/x86/include/asm/kvm_host.h | 9 +-
arch/x86/kvm/x86.c | 71 +++-
include/linux/kvm_host.h | 132 ++++++-
include/linux/kvm_types.h | 12 +
include/uapi/linux/kvm.h | 48 +++
tools/testing/selftests/kvm/.gitignore | 1 +
tools/testing/selftests/kvm/Makefile | 3 +
.../testing/selftests/kvm/include/kvm_util.h | 3 +
.../selftests/kvm/kvm_bin_form_stats.c | 370 ++++++++++++++++++
tools/testing/selftests/kvm/lib/kvm_util.c | 11 +
virt/kvm/kvm_main.c | 237 ++++++++++-
24 files changed, 1401 insertions(+), 90 deletions(-)
create mode 100644 tools/testing/selftests/kvm/kvm_bin_form_stats.c
base-commit: f96be2deac9bca3ef5a2b0b66b71fcef8bad586d
--
2.31.0.208.g409f899ff0-goog
The current way to provide a no-op flag to 'bpf_ringbuf_submit()',
'bpf_ringbuf_discard()' and 'bpf_ringbuf_output()' is to provide a '0'
value.
A '0' value might notify the consumer if it already caught up in processing,
so let's provide a more descriptive notation for this value.
Signed-off-by: Pedro Tammela <pctammela(a)mojatatu.com>
---
include/uapi/linux/bpf.h | 8 ++++++++
tools/include/uapi/linux/bpf.h | 8 ++++++++
tools/testing/selftests/bpf/progs/ima.c | 2 +-
tools/testing/selftests/bpf/progs/ringbuf_bench.c | 2 +-
tools/testing/selftests/bpf/progs/test_ringbuf.c | 2 +-
tools/testing/selftests/bpf/progs/test_ringbuf_multi.c | 2 +-
6 files changed, 20 insertions(+), 4 deletions(-)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 598716742593..100cb2e4c104 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -4058,6 +4058,8 @@ union bpf_attr {
* Copy *size* bytes from *data* into a ring buffer *ringbuf*.
* If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
* of new data availability is sent.
+ * If **BPF_RB_MAY_WAKEUP** is specified in *flags*, notification
+ * of new data availability is sent if needed.
* If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
* of new data availability is sent unconditionally.
* Return
@@ -4066,6 +4068,7 @@ union bpf_attr {
* void *bpf_ringbuf_reserve(void *ringbuf, u64 size, u64 flags)
* Description
* Reserve *size* bytes of payload in a ring buffer *ringbuf*.
+ * *flags* must be 0.
* Return
* Valid pointer with *size* bytes of memory available; NULL,
* otherwise.
@@ -4075,6 +4078,8 @@ union bpf_attr {
* Submit reserved ring buffer sample, pointed to by *data*.
* If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
* of new data availability is sent.
+ * If **BPF_RB_MAY_WAKEUP** is specified in *flags*, notification
+ * of new data availability is sent if needed.
* If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
* of new data availability is sent unconditionally.
* Return
@@ -4085,6 +4090,8 @@ union bpf_attr {
* Discard reserved ring buffer sample, pointed to by *data*.
* If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
* of new data availability is sent.
+ * If **BPF_RB_MAY_WAKEUP** is specified in *flags*, notification
+ * of new data availability is sent if needed.
* If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
* of new data availability is sent unconditionally.
* Return
@@ -4965,6 +4972,7 @@ enum {
* BPF_FUNC_bpf_ringbuf_output flags.
*/
enum {
+ BPF_RB_MAY_WAKEUP = 0,
BPF_RB_NO_WAKEUP = (1ULL << 0),
BPF_RB_FORCE_WAKEUP = (1ULL << 1),
};
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index ab9f2233607c..3d6d324184c0 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -4058,6 +4058,8 @@ union bpf_attr {
* Copy *size* bytes from *data* into a ring buffer *ringbuf*.
* If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
* of new data availability is sent.
+ * If **BPF_RB_MAY_WAKEUP** is specified in *flags*, notification
+ * of new data availability is sent if needed.
* If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
* of new data availability is sent unconditionally.
* Return
@@ -4066,6 +4068,7 @@ union bpf_attr {
* void *bpf_ringbuf_reserve(void *ringbuf, u64 size, u64 flags)
* Description
* Reserve *size* bytes of payload in a ring buffer *ringbuf*.
+ * *flags* must be 0.
* Return
* Valid pointer with *size* bytes of memory available; NULL,
* otherwise.
@@ -4075,6 +4078,8 @@ union bpf_attr {
* Submit reserved ring buffer sample, pointed to by *data*.
* If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
* of new data availability is sent.
+ * If **BPF_RB_MAY_WAKEUP** is specified in *flags*, notification
+ * of new data availability is sent if needed.
* If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
* of new data availability is sent unconditionally.
* Return
@@ -4085,6 +4090,8 @@ union bpf_attr {
* Discard reserved ring buffer sample, pointed to by *data*.
* If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
* of new data availability is sent.
+ * If **BPF_RB_MAY_WAKEUP** is specified in *flags*, notification
+ * of new data availability is sent if needed.
* If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
* of new data availability is sent unconditionally.
* Return
@@ -4959,6 +4966,7 @@ enum {
* BPF_FUNC_bpf_ringbuf_output flags.
*/
enum {
+ BPF_RB_MAY_WAKEUP = 0,
BPF_RB_NO_WAKEUP = (1ULL << 0),
BPF_RB_FORCE_WAKEUP = (1ULL << 1),
};
diff --git a/tools/testing/selftests/bpf/progs/ima.c b/tools/testing/selftests/bpf/progs/ima.c
index 96060ff4ffc6..0f4daced6aad 100644
--- a/tools/testing/selftests/bpf/progs/ima.c
+++ b/tools/testing/selftests/bpf/progs/ima.c
@@ -38,7 +38,7 @@ void BPF_PROG(ima, struct linux_binprm *bprm)
return;
*sample = ima_hash;
- bpf_ringbuf_submit(sample, 0);
+ bpf_ringbuf_submit(sample, BPF_RB_MAY_WAKEUP);
}
return;
diff --git a/tools/testing/selftests/bpf/progs/ringbuf_bench.c b/tools/testing/selftests/bpf/progs/ringbuf_bench.c
index 123607d314d6..808e2e0e3d64 100644
--- a/tools/testing/selftests/bpf/progs/ringbuf_bench.c
+++ b/tools/testing/selftests/bpf/progs/ringbuf_bench.c
@@ -24,7 +24,7 @@ static __always_inline long get_flags()
long sz;
if (!wakeup_data_size)
- return 0;
+ return BPF_RB_MAY_WAKEUP;
sz = bpf_ringbuf_query(&ringbuf, BPF_RB_AVAIL_DATA);
return sz >= wakeup_data_size ? BPF_RB_FORCE_WAKEUP : BPF_RB_NO_WAKEUP;
diff --git a/tools/testing/selftests/bpf/progs/test_ringbuf.c b/tools/testing/selftests/bpf/progs/test_ringbuf.c
index 8ba9959b036b..03a5cbd21356 100644
--- a/tools/testing/selftests/bpf/progs/test_ringbuf.c
+++ b/tools/testing/selftests/bpf/progs/test_ringbuf.c
@@ -21,7 +21,7 @@ struct {
/* inputs */
int pid = 0;
long value = 0;
-long flags = 0;
+long flags = BPF_RB_MAY_WAKEUP;
/* outputs */
long total = 0;
diff --git a/tools/testing/selftests/bpf/progs/test_ringbuf_multi.c b/tools/testing/selftests/bpf/progs/test_ringbuf_multi.c
index edf3b6953533..f33c3fdfb1d6 100644
--- a/tools/testing/selftests/bpf/progs/test_ringbuf_multi.c
+++ b/tools/testing/selftests/bpf/progs/test_ringbuf_multi.c
@@ -71,7 +71,7 @@ int test_ringbuf(void *ctx)
sample->seq = total;
total += 1;
- bpf_ringbuf_submit(sample, 0);
+ bpf_ringbuf_submit(sample, BPF_RB_MAY_WAKEUP);
return 0;
}
--
2.25.1
v1 by Uriel is here: [1].
Since it's been a while, I've dropped the Reviewed-By's.
It depended on commit 83c4e7a0363b ("KUnit: KASAN Integration") which
hadn't been merged yet, so that caused some kerfuffle with applying them
previously and the series was reverted.
This revives the series but makes the kunit_fail_current_test() function
take a format string and logs the file and line number of the failing
code, addressing Alan Maguire's comments on the previous version.
As a result, the patch that makes UBSAN errors was tweaked slightly to
include an error message.
v2 -> v3:
Try and fail to make kunit_fail_current_test() work on CONFIG_KUNIT=m
s/_/__ on the helper func to match others in test.c
v3 -> v4:
Revert to only enabling kunit_fail_current_test() for CONFIG_KUNIT=y
[1] https://lore.kernel.org/linux-kselftest/20200806174326.3577537-1-urielguaja…
Uriel Guajardo (2):
kunit: support failure from dynamic analysis tools
kunit: ubsan integration
include/kunit/test-bug.h | 30 ++++++++++++++++++++++++++++++
lib/kunit/test.c | 39 +++++++++++++++++++++++++++++++++++----
lib/ubsan.c | 3 +++
3 files changed, 68 insertions(+), 4 deletions(-)
create mode 100644 include/kunit/test-bug.h
base-commit: a74e6a014c9d4d4161061f770c9b4f98372ac778
--
2.31.0.rc2.261.g7f71774620-goog
This series improves the defensive posture of sysfs's use of seq_file
to gain the vmap guard pages at the end of vmalloc buffers to stop a
class of recurring flaw[1]. The long-term goal is to switch sysfs from
a buffer to using seq_file directly, but this will take time to refactor.
Included is also a Clang fix for NULL arithmetic and an LKDTM test to
validate vmalloc guard pages.
v4:
- fix NULL arithmetic (Arnd)
- add lkdtm test
- reword commit message
v3: https://lore.kernel.org/lkml/20210401022145.2019422-1-keescook@chromium.org/
v2: https://lore.kernel.org/lkml/20210315174851.622228-1-keescook@chromium.org/
v1: https://lore.kernel.org/lkml/20210312205558.2947488-1-keescook@chromium.org/
Thanks!
-Kees
Arnd Bergmann (1):
seq_file: Fix clang warning for NULL pointer arithmetic
Kees Cook (2):
lkdtm/heap: Add vmalloc linear overflow test
sysfs: Unconditionally use vmalloc for buffer
drivers/misc/lkdtm/core.c | 3 ++-
drivers/misc/lkdtm/heap.c | 21 +++++++++++++++++-
drivers/misc/lkdtm/lkdtm.h | 3 ++-
fs/kernfs/file.c | 9 +++++---
fs/seq_file.c | 5 ++++-
fs/sysfs/file.c | 29 +++++++++++++++++++++++++
include/linux/seq_file.h | 6 +++++
tools/testing/selftests/lkdtm/tests.txt | 3 ++-
8 files changed, 71 insertions(+), 8 deletions(-)
--
2.25.1
v1 by Uriel is here: [1].
Since it's been a while, I've dropped the Reviewed-By's.
It depended on commit 83c4e7a0363b ("KUnit: KASAN Integration") which
hadn't been merged yet, so that caused some kerfuffle with applying them
previously and the series was reverted.
This revives the series but makes the kunit_fail_current_test() function
take a format string and logs the file and line number of the failing
code, addressing Alan Maguire's comments on the previous version.
As a result, the patch that makes UBSAN errors was tweaked slightly to
include an error message.
v2 -> v3:
Try and fail to make kunit_fail_current_test() work on CONFIG_KUNIT=m
s/_/__ on the helper func to match others in test.c
v3 -> v4:
Revert to only enabling kunit_fail_current_test() for CONFIG_KUNIT=y
v4 -> v5:
Delete blank line to make checkpatch.pl --strict happy
[1] https://lore.kernel.org/linux-kselftest/20200806174326.3577537-1-urielguaja…
Uriel Guajardo (2):
kunit: support failure from dynamic analysis tools
kunit: ubsan integration
include/kunit/test-bug.h | 29 +++++++++++++++++++++++++++++
lib/kunit/test.c | 39 +++++++++++++++++++++++++++++++++++----
lib/ubsan.c | 3 +++
3 files changed, 67 insertions(+), 4 deletions(-)
create mode 100644 include/kunit/test-bug.h
base-commit: 1678e493d530e7977cce34e59a86bb86f3c5631e
--
2.31.0.208.g409f899ff0-goog
This patch set has several miscellaneous fixes to resctrl selftest tool
that are easily visible to user. V1 had fixes to CAT test and CMT test
but they were dropped in V2 because having them here made the patchset
humongous. So, changes to CAT test and CMT test will be posted in another
patchset.
Change Log:
v6:
- Add Tested-by: Babu Moger <babu.moger(a)amd.com>.
- Replace "cat" by CAT_STR etc (Babu).
- Capitalize the first letter of printed message (Babu).
v5:
- Address various comments from Shuah Khan:
1. Move a few fixing patches before cleaning patches.
2. Call kselftest APIs to log test results instead of printf().
3. Add .gitignore to ignore resctrl_tests.
4. Share show_cache_info() in CAT and CMT tests.
5. Define long_mask, cbm_mask, count_of_bits etc as static variables.
v4:
- Address various comments from Shuah Khan:
1. Combine a few patches e.g. a couple of fixing typos patches into one
and a couple of unmounting patches into one etc.
2. Add config file.
3. Remove "Fixes" tags.
4. Change strcmp() to strncmp().
5. Move the global variable fixing patch to the patch 1 so that the
compilation issue is fixed first.
Please note:
- I didn't move the patch of renaming CQM to CMT to the end of the series
because code and commit messages in a few other patches depend on the
new term of "CMT". If move the renaming patch to the end, the previous
patches use the old "CQM" term and code which will be changed soon at
the end of series and will cause more code and explanations.
[v3: https://lkml.org/lkml/2020/10/28/137]
v3:
Address various comments (commit messages, return value on test failure,
print failure info on test failure etc) from Reinette and Tony.
[v2: https://lore.kernel.org/linux-kselftest/cover.1589835155.git.sai.praneeth.p…]
v2:
1. Dropped changes to CAT test and CMT test as they will be posted in a later
series.
2. Added several other fixes
[v1: https://lore.kernel.org/linux-kselftest/cover.1583657204.git.sai.praneeth.p…]
Fenghua Yu (19):
selftests/resctrl: Enable gcc checks to detect buffer overflows
selftests/resctrl: Fix compilation issues for global variables
selftests/resctrl: Fix compilation issues for other global variables
selftests/resctrl: Clean up resctrl features check
selftests/resctrl: Fix missing options "-n" and "-p"
selftests/resctrl: Rename CQM test as CMT test
selftests/resctrl: Call kselftest APIs to log test results
selftests/resctrl: Share show_cache_info() by CAT and CMT tests
selftests/resctrl: Add config dependencies
selftests/resctrl: Check for resctrl mount point only if resctrl FS is
supported
selftests/resctrl: Use resctrl/info for feature detection
selftests/resctrl: Fix MBA/MBM results reporting format
selftests/resctrl: Don't hard code value of "no_of_bits" variable
selftests/resctrl: Modularize resctrl test suite main() function
selftests/resctrl: Skip the test if requested resctrl feature is not
supported
selftests/resctrl: Fix unmount resctrl FS
selftests/resctrl: Fix incorrect parsing of iMC counters
selftests/resctrl: Fix checking for < 0 for unsigned values
selftests/resctrl: Create .gitignore to include resctrl_tests
Reinette Chatre (2):
selftests/resctrl: Ensure sibling CPU is not same as original CPU
selftests/resctrl: Fix a printed message
tools/testing/selftests/resctrl/.gitignore | 2 +
tools/testing/selftests/resctrl/Makefile | 2 +-
tools/testing/selftests/resctrl/README | 4 +-
tools/testing/selftests/resctrl/cache.c | 52 +++++-
tools/testing/selftests/resctrl/cat_test.c | 57 ++----
.../resctrl/{cqm_test.c => cmt_test.c} | 75 +++-----
tools/testing/selftests/resctrl/config | 2 +
tools/testing/selftests/resctrl/fill_buf.c | 4 +-
tools/testing/selftests/resctrl/mba_test.c | 43 ++---
tools/testing/selftests/resctrl/mbm_test.c | 42 ++---
tools/testing/selftests/resctrl/resctrl.h | 29 +++-
.../testing/selftests/resctrl/resctrl_tests.c | 163 ++++++++++++------
tools/testing/selftests/resctrl/resctrl_val.c | 95 ++++++----
tools/testing/selftests/resctrl/resctrlfs.c | 134 ++++++++------
14 files changed, 408 insertions(+), 296 deletions(-)
create mode 100644 tools/testing/selftests/resctrl/.gitignore
rename tools/testing/selftests/resctrl/{cqm_test.c => cmt_test.c} (56%)
create mode 100644 tools/testing/selftests/resctrl/config
--
2.31.0
A 'single_cpu_test' parameter is odd and it does not exist
anymore. Instead there was introduced a 'nr_threads' one.
If it is not set it behaves as the former parameter.
That is why update a "stress mode" according to this change
specifying number of workers which are equal to number of CPUs.
Also update an output of help message based on a new interface.
CC: linux-kselftest(a)vger.kernel.org
CC: Shuah Khan <shuah(a)kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki(a)gmail.com>
---
tools/testing/selftests/vm/test_vmalloc.sh | 21 +++++++++++----------
1 file changed, 11 insertions(+), 10 deletions(-)
diff --git a/tools/testing/selftests/vm/test_vmalloc.sh b/tools/testing/selftests/vm/test_vmalloc.sh
index 06d2bb109f06..d73b846736f1 100755
--- a/tools/testing/selftests/vm/test_vmalloc.sh
+++ b/tools/testing/selftests/vm/test_vmalloc.sh
@@ -11,6 +11,7 @@
TEST_NAME="vmalloc"
DRIVER="test_${TEST_NAME}"
+NUM_CPUS=`grep -c ^processor /proc/cpuinfo`
# 1 if fails
exitcode=1
@@ -22,9 +23,9 @@ ksft_skip=4
# Static templates for performance, stressing and smoke tests.
# Also it is possible to pass any supported parameters manualy.
#
-PERF_PARAM="single_cpu_test=1 sequential_test_order=1 test_repeat_count=3"
-SMOKE_PARAM="single_cpu_test=1 test_loop_count=10000 test_repeat_count=10"
-STRESS_PARAM="test_repeat_count=20"
+PERF_PARAM="sequential_test_order=1 test_repeat_count=3"
+SMOKE_PARAM="test_loop_count=10000 test_repeat_count=10"
+STRESS_PARAM="nr_threads=$NUM_CPUS test_repeat_count=20"
check_test_requirements()
{
@@ -58,8 +59,8 @@ run_perfformance_check()
run_stability_check()
{
- echo "Run stability tests. In order to stress vmalloc subsystem we run"
- echo "all available test cases on all available CPUs simultaneously."
+ echo "Run stability tests. In order to stress vmalloc subsystem all"
+ echo "available test cases are run by NUM_CPUS workers simultaneously."
echo "It will take time, so be patient."
modprobe $DRIVER $STRESS_PARAM > /dev/null 2>&1
@@ -92,17 +93,17 @@ usage()
echo "# Shows help message"
echo "./${DRIVER}.sh"
echo
- echo "# Runs 1 test(id_1), repeats it 5 times on all online CPUs"
- echo "./${DRIVER}.sh run_test_mask=1 test_repeat_count=5"
+ echo "# Runs 1 test(id_1), repeats it 5 times by NUM_CPUS workers"
+ echo "./${DRIVER}.sh nr_threads=$NUM_CPUS run_test_mask=1 test_repeat_count=5"
echo
echo -n "# Runs 4 tests(id_1|id_2|id_4|id_16) on one CPU with "
echo "sequential order"
- echo -n "./${DRIVER}.sh single_cpu_test=1 sequential_test_order=1 "
+ echo -n "./${DRIVER}.sh sequential_test_order=1 "
echo "run_test_mask=23"
echo
- echo -n "# Runs all tests on all online CPUs, shuffled order, repeats "
+ echo -n "# Runs all tests by NUM_CPUS workers, shuffled order, repeats "
echo "20 times"
- echo "./${DRIVER}.sh test_repeat_count=20"
+ echo "./${DRIVER}.sh nr_threads=$NUM_CPUS test_repeat_count=20"
echo
echo "# Performance analysis"
echo "./${DRIVER}.sh performance"
--
2.20.1
TL;DR
$ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit
Per suggestion from Ted [1], we can reduce the amount of typing by
assuming a convention that these files are named '.kunitconfig'.
In the case of [1], we now have
$ ./tools/testing/kunit/kunit.py run --kunitconfig=fs/ext4
Also add in such a fragment for kunit itself so we can give that as an
example more close to home (and thus less likely to be accidentally
broken).
[1] https://lore.kernel.org/linux-ext4/YCNF4yP1dB97zzwD@mit.edu/
Signed-off-by: Daniel Latypov <dlatypov(a)google.com>
---
lib/kunit/.kunitconfig | 3 +++
tools/testing/kunit/kunit.py | 4 +++-
tools/testing/kunit/kunit_kernel.py | 2 ++
tools/testing/kunit/kunit_tool_test.py | 6 ++++++
4 files changed, 14 insertions(+), 1 deletion(-)
create mode 100644 lib/kunit/.kunitconfig
diff --git a/lib/kunit/.kunitconfig b/lib/kunit/.kunitconfig
new file mode 100644
index 000000000000..9235b7d42d38
--- /dev/null
+++ b/lib/kunit/.kunitconfig
@@ -0,0 +1,3 @@
+CONFIG_KUNIT=y
+CONFIG_KUNIT_TEST=y
+CONFIG_KUNIT_EXAMPLE_TEST=y
diff --git a/tools/testing/kunit/kunit.py b/tools/testing/kunit/kunit.py
index d5144fcb03ac..5da8fb3762f9 100755
--- a/tools/testing/kunit/kunit.py
+++ b/tools/testing/kunit/kunit.py
@@ -184,7 +184,9 @@ def add_common_opts(parser) -> None:
help='Run all KUnit tests through allyesconfig',
action='store_true')
parser.add_argument('--kunitconfig',
- help='Path to Kconfig fragment that enables KUnit tests',
+ help='Path to Kconfig fragment that enables KUnit tests.'
+ ' If given a directory, (e.g. lib/kunit), "/.kunitconfig" '
+ 'will get automatically appended.',
metavar='kunitconfig')
def add_build_opts(parser) -> None:
diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py
index f309a33256cd..89a7d4024e87 100644
--- a/tools/testing/kunit/kunit_kernel.py
+++ b/tools/testing/kunit/kunit_kernel.py
@@ -132,6 +132,8 @@ class LinuxSourceTree(object):
return
if kunitconfig_path:
+ if os.path.isdir(kunitconfig_path):
+ kunitconfig_path = os.path.join(kunitconfig_path, KUNITCONFIG_PATH)
if not os.path.exists(kunitconfig_path):
raise ConfigError(f'Specified kunitconfig ({kunitconfig_path}) does not exist')
else:
diff --git a/tools/testing/kunit/kunit_tool_test.py b/tools/testing/kunit/kunit_tool_test.py
index 1ad3049e9069..2e809dd956a7 100755
--- a/tools/testing/kunit/kunit_tool_test.py
+++ b/tools/testing/kunit/kunit_tool_test.py
@@ -251,6 +251,12 @@ class LinuxSourceTreeTest(unittest.TestCase):
with tempfile.NamedTemporaryFile('wt') as kunitconfig:
tree = kunit_kernel.LinuxSourceTree('', kunitconfig_path=kunitconfig.name)
+ def test_dir_kunitconfig(self):
+ with tempfile.TemporaryDirectory('') as dir:
+ with open(os.path.join(dir, '.kunitconfig'), 'w') as f:
+ pass
+ tree = kunit_kernel.LinuxSourceTree('', kunitconfig_path=dir)
+
# TODO: add more test cases.
base-commit: b12b47249688915e987a9a2a393b522f86f6b7ab
--
2.30.0.617.g56c4b15f3c-goog
This patch set has several miscellaneous fixes to resctrl selftest tool
that are easily visible to user. V1 had fixes to CAT test and CMT test
but they were dropped in V2 because having them here made the patchset
humongous. So, changes to CAT test and CMT test will be posted in another
patchset.
Change Log:
v5:
- Address various comments from Shuah Khan:
1. Move a few fixing patches before cleaning patches.
2. Call kselftest APIs to log test results instead of printf().
3. Add .gitignore to ignore resctrl_tests.
4. Share show_cache_info() in CAT and CMT tests.
5. Define long_mask, cbm_mask, count_of_bits etc as static variables.
v4:
- Address various comments from Shuah Khan:
1. Combine a few patches e.g. a couple of fixing typos patches into one
and a couple of unmounting patches into one etc.
2. Add config file.
3. Remove "Fixes" tags.
4. Change strcmp() to strncmp().
5. Move the global variable fixing patch to the patch 1 so that the
compilation issue is fixed first.
Please note:
- I didn't move the patch of renaming CQM to CMT to the end of the series
because code and commit messages in a few other patches depend on the
new term of "CMT". If move the renaming patch to the end, the previous
patches use the old "CQM" term and code which will be changed soon at
the end of series and will cause more code and explanations.
[v3: https://lkml.org/lkml/2020/10/28/137]
v3:
Address various comments (commit messages, return value on test failure,
print failure info on test failure etc) from Reinette and Tony.
[v2: https://lore.kernel.org/linux-kselftest/cover.1589835155.git.sai.praneeth.p…]
v2:
1. Dropped changes to CAT test and CMT test as they will be posted in a later
series.
2. Added several other fixes
[v1: https://lore.kernel.org/linux-kselftest/cover.1583657204.git.sai.praneeth.p…]
Fenghua Yu (19):
selftests/resctrl: Enable gcc checks to detect buffer overflows
selftests/resctrl: Fix compilation issues for global variables
selftests/resctrl: Fix compilation issues for other global variables
selftests/resctrl: Clean up resctrl features check
selftests/resctrl: Fix missing options "-n" and "-p"
selftests/resctrl: Rename CQM test as CMT test
selftests/resctrl: Call kselftest APIs to log test results
selftests/resctrl: Share show_cache_info() by CAT and CMT tests
selftests/resctrl: Add config dependencies
selftests/resctrl: Check for resctrl mount point only if resctrl FS is
supported
selftests/resctrl: Use resctrl/info for feature detection
selftests/resctrl: Fix MBA/MBM results reporting format
selftests/resctrl: Don't hard code value of "no_of_bits" variable
selftests/resctrl: Modularize resctrl test suite main() function
selftests/resctrl: Skip the test if requested resctrl feature is not
supported
selftests/resctrl: Fix unmount resctrl FS
selftests/resctrl: Fix incorrect parsing of iMC counters
selftests/resctrl: Fix checking for < 0 for unsigned values
selftests/resctrl: Create .gitignore to include resctrl_tests
Reinette Chatre (2):
selftests/resctrl: Ensure sibling CPU is not same as original CPU
selftests/resctrl: Fix a printed message
tools/testing/selftests/resctrl/.gitignore | 2 +
tools/testing/selftests/resctrl/Makefile | 2 +-
tools/testing/selftests/resctrl/README | 4 +-
tools/testing/selftests/resctrl/cache.c | 52 +++++-
tools/testing/selftests/resctrl/cat_test.c | 57 ++----
.../resctrl/{cqm_test.c => cmt_test.c} | 75 +++-----
tools/testing/selftests/resctrl/config | 2 +
tools/testing/selftests/resctrl/fill_buf.c | 4 +-
tools/testing/selftests/resctrl/mba_test.c | 43 ++---
tools/testing/selftests/resctrl/mbm_test.c | 42 ++---
tools/testing/selftests/resctrl/resctrl.h | 29 +++-
.../testing/selftests/resctrl/resctrl_tests.c | 163 ++++++++++++------
tools/testing/selftests/resctrl/resctrl_val.c | 95 ++++++----
tools/testing/selftests/resctrl/resctrlfs.c | 134 ++++++++------
14 files changed, 408 insertions(+), 296 deletions(-)
create mode 100644 tools/testing/selftests/resctrl/.gitignore
rename tools/testing/selftests/resctrl/{cqm_test.c => cmt_test.c} (56%)
create mode 100644 tools/testing/selftests/resctrl/config
--
2.30.1
This series aims to clarify the behavior of
KVM_GET_EMULATED_CPUID and KVM_GET_SUPPORTED
ioctls, and fix a corner case where the nent field of the
struct kvm_cpuid2 is matching the amount of entries that kvm returns.
Patch 1 proposes the nent field fix to cpuid.c,
patch 2 updates the ioctl documentation accordingly and
patches 3 and 4 provide a selftest to check KVM_GET_EMULATED_CPUID
accordingly.
Emanuele Giuseppe Esposito (4):
kvm: cpuid: adjust the returned nent field of kvm_cpuid2 for
KVM_GET_SUPPORTED_CPUID and KVM_GET_EMULATED_CPUID
Documentation: kvm: update KVM_GET_EMULATED_CPUID ioctl description
selftests: add kvm_get_emulated_cpuid
selftests: kvm: add get_emulated_cpuid test
Documentation/virt/kvm/api.rst | 10 +-
arch/x86/kvm/cpuid.c | 6 +
tools/testing/selftests/kvm/.gitignore | 1 +
tools/testing/selftests/kvm/Makefile | 1 +
.../selftests/kvm/include/x86_64/processor.h | 1 +
.../selftests/kvm/lib/x86_64/processor.c | 33 ++++
.../selftests/kvm/x86_64/get_emulated_cpuid.c | 183 ++++++++++++++++++
7 files changed, 229 insertions(+), 6 deletions(-)
create mode 100644 tools/testing/selftests/kvm/x86_64/get_emulated_cpuid.c
--
2.30.2