From: Daniel Latypov <dlatypov@google.com>
To: David Gow <davidgow@google.com>
Cc: Marco Elver <elver@google.com>,
Brendan Higgins <brendanhiggins@google.com>,
Shuah Khan <skhan@linuxfoundation.org>,
Dmitry Vyukov <dvyukov@google.com>,
KUnit Development <kunit-dev@googlegroups.com>,
kasan-dev <kasan-dev@googlegroups.com>,
"open list:KERNEL SELFTEST FRAMEWORK"
<linux-kselftest@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] kunit: tool: Add x86_64-smp architecture for SMP testing
Date: Thu, 19 May 2022 10:11:06 -0700 [thread overview]
Message-ID: <CAGS_qxqsF-soqSM7-cO+tRD1Rg5fqrA07TGLRruxPE4i_rLdJw@mail.gmail.com> (raw)
In-Reply-To: <CABVgOS=X51T_=hwTumnzL2yECgcshWBp1RT0F3GiT3+Fe_vang@mail.gmail.com>
On Thu, May 19, 2022 at 6:15 AM David Gow <davidgow@google.com> wrote:
>
> I tend to agree that having both would be nice: I think there are
> enough useful "machine configs" that trying to maintain, e.g, a 1:1
> mapping with kernel architectures is going to leave a bunch of things
> on the table, particularly as we add more tests for, e.g., drivers and
> specific CPU models.
I agree that we don't necessarily need to maintain a 1:1 mapping.
But I feel like we should have a pretty convincing reason for doing
so, e.g. support for a CPU that requires we add in a bunch of
kconfigs.
This particular one feels simple enough to me.
Given we already have to put specific instructions in the
kcsan/.kunitconfig, I don't know if there's much of a difference in
cost between these two commands
$ ./tools/testing/kunit/kunit.py run --kunitconfig=kernel/kcsan
--arch=x86_64-smp
$ ./tools/testing/kunit/kunit.py run --kunitconfig=kernel/kcsan
--arch=x86_64 --kconfig_add CONFIG_SMP=y --qemu_args "-smp 8"
I've generally learned to prefer more explicit commands like the
second, even if they're quite a bit longer.
But I have the following biases
* I use FZF heavily, so I don't re-type long commands much
* I'm the person who proposed --kconfig_add and --qemu_args, so of
course I'd think the longer form is easy to understand.
so I'm not in a position to object to this change.
Changing topics:
Users can overwrite the '-smp 8' here via --qemu_args [1], so I'm much
less worried about hard-coding any specific value in this file
anymore.
And given that, I think a more "natural" value for this file would be "-smp 2".
I think anything that needs more than that should explicitly should --qemu_args.
Thoughts?
[1] tested with --qemu_args='-smp 4' --qemu_args='-smp 8'
and I see the following in the test.log
smpboot: Allowing 8 CPUs, 0 hotplug CPUs
so QEMU respects the last value passed in, as expected.
>
> The problem, of course, is that the --kconfig_add flags don't allow us
> to override anything explicitly stated in either the kunitconfig or
> qemu_config (and I imagine there could be problems with --qemu_config,
> too).
This patch would fix that.
https://lore.kernel.org/linux-kselftest/20220519164512.3180360-1-dlatypov@google.com
It introduces an overwriting priority of
* --kconfig_add
* kunitconfig / --kunitconfig
* qemu_config
next prev parent reply other threads:[~2022-05-19 17:11 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-18 7:32 [PATCH 1/2] kunit: tool: Add x86_64-smp architecture for SMP testing David Gow
2022-05-18 7:32 ` [PATCH 2/2] kcsan: test: Add a .kunitconfig to run KCSAN tests David Gow
2022-05-18 9:21 ` Marco Elver
2022-05-19 13:08 ` David Gow
2022-05-19 13:24 ` Marco Elver
2022-07-14 20:22 ` Daniel Latypov
2022-07-14 21:40 ` Marco Elver
2022-07-14 23:45 ` Daniel Latypov
2022-07-14 23:47 ` Daniel Latypov
2022-07-15 6:49 ` David Gow
2022-05-18 17:12 ` Daniel Latypov
2022-07-06 19:53 ` Brendan Higgins
2022-05-18 9:22 ` [PATCH 1/2] kunit: tool: Add x86_64-smp architecture for SMP testing Marco Elver
2022-05-18 15:31 ` Daniel Latypov
2022-05-18 15:35 ` Marco Elver
2022-05-18 15:39 ` Daniel Latypov
2022-05-18 17:05 ` Daniel Latypov
2022-05-19 13:15 ` David Gow
2022-05-19 17:11 ` Daniel Latypov [this message]
2022-07-06 19:43 ` Brendan Higgins
2022-07-06 19:44 ` Brendan Higgins
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