| Message ID | 20221125084306.1063074-1-davidgow@google.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v4,1/3] kunit: Provide a static key to check if KUnit is actively running tests | expand |
On Fri, Nov 25, 2022 at 04:43:04PM +0800, David Gow wrote: > KUnit does a few expensive things when enabled. This hasn't been a > problem because KUnit was only enabled on test kernels, but with a few > people enabling (but not _using_) KUnit on production systems, we need a > runtime way of handling this. > > Provide a 'kunit_running' static key (defaulting to false), which allows > us to hide any KUnit code behind a static branch. This should reduce the > performance impact (on other code) of having KUnit enabled to a single > NOP when no tests are running. > > Note that, while it looks unintuitive, tests always run entirely within > __kunit_test_suites_init(), so it's safe to decrement the static key at > the end of this function, rather than in __kunit_test_suites_exit(), > which is only there to clean up results in debugfs. > > Signed-off-by: David Gow <davidgow@google.com> > Reviewed-by: Daniel Latypov <dlatypov@google.com> > --- > This should be a no-op (other than a possible performance improvement) > functionality-wise, and lays the groundwork for a more optimised static > stub implementation. > > The remaining patches in the series add a kunit_get_current_test() > function which is a more friendly and performant wrapper around > current->kunit_test, and use this in the slub test. They also improve > the documentation a bit. > > If there are no objections, we'll take the whole series via the KUnit > tree. > > Changes since v3: > https://lore.kernel.org/linux-kselftest/20221119081252.3864249-1-davidgow@google.com/ > - Use DECLARE_STATIC_KEY_FALSE() -- thanks Daniel! > > No changes since v2: > https://lore.kernel.org/all/20221025071907.1251820-1-davidgow@google.com/ > > Changes since v1: > https://lore.kernel.org/linux-kselftest/20221021072854.333010-1-davidgow@google.com/ > - No changes in this patch. > - Patch 2/3 is reworked, patch 3/3 is new. > > --- > include/kunit/test.h | 4 ++++ > lib/kunit/test.c | 6 ++++++ > 2 files changed, 10 insertions(+) > > diff --git a/include/kunit/test.h b/include/kunit/test.h > index 4666a4d199ea..87ea90576b50 100644 > --- a/include/kunit/test.h > +++ b/include/kunit/test.h > @@ -16,6 +16,7 @@ > #include <linux/container_of.h> > #include <linux/err.h> > #include <linux/init.h> > +#include <linux/jump_label.h> > #include <linux/kconfig.h> > #include <linux/kref.h> > #include <linux/list.h> > @@ -27,6 +28,9 @@ > > #include <asm/rwonce.h> > > +/* Static key: true if any KUnit tests are currently running */ > +DECLARE_STATIC_KEY_FALSE(kunit_running); > + > struct kunit; > > /* Size of log associated with test. */ > diff --git a/lib/kunit/test.c b/lib/kunit/test.c > index 1c9d8d962d67..87a5d795843b 100644 > --- a/lib/kunit/test.c > +++ b/lib/kunit/test.c > @@ -20,6 +20,8 @@ > #include "string-stream.h" > #include "try-catch-impl.h" > > +DEFINE_STATIC_KEY_FALSE(kunit_running); > + > #if IS_BUILTIN(CONFIG_KUNIT) > /* > * Fail the current test and print an error message to the log. > @@ -615,10 +617,14 @@ int __kunit_test_suites_init(struct kunit_suite * const * const suites, int num_ > return 0; > } > > + static_branch_inc(&kunit_running); Is it expected there will be multiple tests running? (I was expecting "static_branch_enable"). > + > for (i = 0; i < num_suites; i++) { > kunit_init_suite(suites[i]); > kunit_run_tests(suites[i]); > } > + > + static_branch_dec(&kunit_running); > return 0; > } > EXPORT_SYMBOL_GPL(__kunit_test_suites_init); > -- > 2.38.1.584.g0f3c55d4c2-goog > Regardless: Reviewed-by: Kees Cook <keescook@chromium.org>
On Thu, Dec 1, 2022 at 4:53 PM Kees Cook <keescook@chromium.org> wrote: > > + static_branch_inc(&kunit_running); > > Is it expected there will be multiple tests running? (I was expecting > "static_branch_enable"). It shouldn't normally happen, no. One possible use case: KUnit's unit tests for itself create fake test objects and operate on them. They don't currently exercise this particular code though, afaict (maybe they should). > > > + > > for (i = 0; i < num_suites; i++) { > > kunit_init_suite(suites[i]); > > kunit_run_tests(suites[i]); > > } > > + > > + static_branch_dec(&kunit_running); > > return 0; > > } > > EXPORT_SYMBOL_GPL(__kunit_test_suites_init); > > -- > > 2.38.1.584.g0f3c55d4c2-goog > > > > Regardless: > > Reviewed-by: Kees Cook <keescook@chromium.org> > > -- > Kees Cook Daniel
diff --git a/include/kunit/test.h b/include/kunit/test.h index 4666a4d199ea..87ea90576b50 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -16,6 +16,7 @@ #include <linux/container_of.h> #include <linux/err.h> #include <linux/init.h> +#include <linux/jump_label.h> #include <linux/kconfig.h> #include <linux/kref.h> #include <linux/list.h> @@ -27,6 +28,9 @@ #include <asm/rwonce.h> +/* Static key: true if any KUnit tests are currently running */ +DECLARE_STATIC_KEY_FALSE(kunit_running); + struct kunit; /* Size of log associated with test. */ diff --git a/lib/kunit/test.c b/lib/kunit/test.c index 1c9d8d962d67..87a5d795843b 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -20,6 +20,8 @@ #include "string-stream.h" #include "try-catch-impl.h" +DEFINE_STATIC_KEY_FALSE(kunit_running); + #if IS_BUILTIN(CONFIG_KUNIT) /* * Fail the current test and print an error message to the log. @@ -615,10 +617,14 @@ int __kunit_test_suites_init(struct kunit_suite * const * const suites, int num_ return 0; } + static_branch_inc(&kunit_running); + for (i = 0; i < num_suites; i++) { kunit_init_suite(suites[i]); kunit_run_tests(suites[i]); } + + static_branch_dec(&kunit_running); return 0; } EXPORT_SYMBOL_GPL(__kunit_test_suites_init);