Received-SPF: pass (google.com: domain of linux-kernel+bounces-130816-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161;
Date: Wed, 3 Apr 2024 18:34:12 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Guenter Roeck <linux@roeck-us.net>
Cc: linux-kselftest@vger.kernel.org, David Airlie <airlied@gmail.com>, Arnd
 Bergmann <arnd@arndb.de>, =?UTF-8?B?TWHDrXJh?= Canal <mcanal@igalia.com>,
 Dan Carpenter <dan.carpenter@linaro.org>, Kees Cook
 <keescook@chromium.org>, Daniel Diaz <daniel.diaz@linaro.org>, David Gow
 <davidgow@google.com>, Arthur Grillo <arthurgrillo@riseup.net>, Brendan
 Higgins <brendan.higgins@linux.dev>, Naresh Kamboju
 <naresh.kamboju@linaro.org>, Maarten Lankhorst
 <maarten.lankhorst@linux.intel.com>, Andrew Morton
 <akpm@linux-foundation.org>, Maxime Ripard <mripard@kernel.org>, Ville
 =?UTF-8?B?U3lyasOkbMOk?= <ville.syrjala@linux.intel.com>, Daniel Vetter
 <daniel@ffwll.ch>, Thomas Zimmermann <tzimmermann@suse.de>,
 dri-devel@lists.freedesktop.org, kunit-dev@googlegroups.com,
 linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
 linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
 linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
 linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org,
 linux-sh@vger.kernel.org, loongarch@lists.linux.dev,
 netdev@vger.kernel.org, x86@kernel.org, Linux Kernel Functional Testing
 <lkft@linaro.org>, Eric Dumazet <edumazet@google.com>
Subject: Re: [PATCH v3 06/15] net: kunit: Suppress lock warning noise at end
 of dev_addr_lists tests
Message-ID: <20240403183412.16254318@kernel.org>
In-Reply-To: <20240403131936.787234-7-linux@roeck-us.net>
References: <20240403131936.787234-1-linux@roeck-us.net>
	<20240403131936.787234-7-linux@roeck-us.net>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit

On Wed,  3 Apr 2024 06:19:27 -0700 Guenter Roeck wrote:
> dev_addr_lists_test generates lock warning noise at the end of tests
> if lock debugging is enabled. There are two sets of warnings.
> 
> WARNING: CPU: 0 PID: 689 at kernel/locking/mutex.c:923 __mutex_unlock_slowpath.constprop.0+0x13c/0x368
> DEBUG_LOCKS_WARN_ON(__owner_task(owner) != __get_current())
> 
> WARNING: kunit_try_catch/1336 still has locks held!
> 
> KUnit test cleanup is not guaranteed to run in the same thread as the test
> itself. For this test, this means that rtnl_lock() and rtnl_unlock() may
> be called from different threads. This triggers the warnings.
> Suppress the warnings because they are irrelevant for the test and just
> confusing and distracting.
> 
> The first warning can be suppressed by using START_SUPPRESSED_WARNING()
> and END_SUPPRESSED_WARNING() around the call to rtnl_unlock(). To suppress
> the second warning, it is necessary to set debug_locks_silent while the
> rtnl lock is held.

Is it okay if I move the locking into the tests, instead?
It's only 4 lines more and no magic required, seems to work fine.