linux-kernel - Re: [PATCH 1/2] kunit: tool: Add x86_64-smp architecture for SMP testing

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAGS_qxr4vTSEtcGGFyoZibga2Q_Avp9pFD78GOA3W9o6F9RVRQ@mail.gmail.com>
Date:   Wed, 18 May 2022 08:39:16 -0700
From:   Daniel Latypov <dlatypov@...gle.com>
To:     Marco Elver <elver@...gle.com>
Cc:     David Gow <davidgow@...gle.com>,
        Brendan Higgins <brendanhiggins@...gle.com>,
        Shuah Khan <skhan@...uxfoundation.org>,
        Dmitry Vyukov <dvyukov@...gle.com>, kunit-dev@...glegroups.com,
        kasan-dev@...glegroups.com, linux-kselftest@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] kunit: tool: Add x86_64-smp architecture for SMP testing

On Wed, May 18, 2022 at 8:36 AM Marco Elver <elver@...gle.com> wrote:
>
> On Wed, 18 May 2022 at 17:31, Daniel Latypov <dlatypov@...gle.com> wrote:
> >
> > On Wed, May 18, 2022 at 12:32 AM 'David Gow' via KUnit Development
> > <kunit-dev@...glegroups.com> wrote:
> > >
> > > Add a new QEMU config for kunit_tool, x86_64-smp, which provides an
> > > 8-cpu SMP setup. No other kunit_tool configurations provide an SMP
> > > setup, so this is the best bet for testing things like KCSAN, which
> > > require a multicore/multi-cpu system.
> > >
> > > The choice of 8 CPUs is pretty arbitrary: it's enough to get tests like
> > > KCSAN to run with a nontrivial number of worker threads, while still
> > > working relatively quickly on older machines.
> > >
> >
> > Since it's arbitrary, I somewhat prefer the idea of leaving up
> > entirely to the caller
> > i.e.
> > $ kunit.py run --kconfig_add=CONFIG_SMP=y --qemu_args '-smp 8'
> >
> > We could add CONFIG_SMP=y to the default qemu_configs/*.py and do
> > $ kunit.py run --qemu_args '-smp 8'
> > but I'd prefer the first, even if it is more verbose.
> >
> > Marco, does this seem reasonable from your perspective?
>
> Either way works. But I wouldn't mind a sane default though, where
> that default can be overridden with custom number of CPUs.
>

Ack.
Let me clean up what I have for --qemu_args and send it out for discussion.

One downside I see to adding more qemu_configs is that --arch now
becomes more kunit-specific.
Before, a user could assume "oh, it's just what I pass in to make ARCH=...".
This new "--arch=x86_64-smp" violates that. I don't personally see it
being that confusing, but I still worry.