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From:   Brendan Higgins <brendanhiggins@google.com>
Date:   Thu, 15 Apr 2021 12:35:41 -0700
Message-ID: <CAFd5g45Qx9xyrPz1U36PXtBYFf+nOk2K=anOpBobLS+2xd8NCw@mail.gmail.com>
Subject: Re: [PATCH v4] Documentation: kunit: add tips for running KUnit
To:     Daniel Latypov <dlatypov@google.com>
Cc:     David Gow <davidgow@google.com>,
        Alan Maguire <alan.maguire@oracle.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        KUnit Development <kunit-dev@googlegroups.com>,
        "open list:KERNEL SELFTEST FRAMEWORK" 
        <linux-kselftest@vger.kernel.org>,
        Shuah Khan <skhan@linuxfoundation.org>
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On Wed, Apr 14, 2021 at 3:23 PM Daniel Latypov <dlatypov@google.com> wrote:
>
> 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@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@google.com>
> Reviewed-by: David Gow <davidgow@google.com>

Reviewed-by: Brendan Higgins <brendanhiggins@google.com>