Re: [PATCH v4] Makefile.compiler: replace cc-ifversion with compiler-specific macros

From: Nick Desaulniers <ndesaulniers@google.com>
To: "Ricardo Cañuelo" <ricardo.canuelo@collabora.com>
Cc: Shreeya Patel <shreeya.patel@collabora.com>,
	Michal Marek <michal.lkml@markovi.net>,
	 Masahiro Yamada <masahiroy@kernel.org>,
	 Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	clang-built-linux <llvm@lists.linux.dev>,
	 Bill Wendling <morbo@google.com>,
	Nathan Chancellor <nathan@kernel.org>,
	regressions@lists.linux.dev,
	 "gustavo.padovan@collabora.com" <gustavo.padovan@collabora.com>,
	 Guillaume Charles Tucker <guillaume.tucker@collabora.com>,
	denys.f@collabora.com,  kernelci@lists.linux.dev
Subject: Re: [PATCH v4] Makefile.compiler: replace cc-ifversion with compiler-specific macros
Date: Wed, 17 May 2023 09:27:41 -0700	[thread overview]
Message-ID: <CAKwvOdkFxu9hYSL_RCXadpR0dQd1+dZmAUVXdfFiLUfxg4D_Xw@mail.gmail.com> (raw)
In-Reply-To: <b5d0cf82-0e42-f6a1-c9f5-c145fdc4c622@collabora.com>

On Wed, May 17, 2023 at 8:39 AM Ricardo Cañuelo
<ricardo.canuelo@collabora.com> wrote:
>
> Hi Nick,
>
> On 16/5/23 1:01, Nick Desaulniers wrote:
> > Can you please help verify this failure by hand, and see if applying
> > https://github.com/ClangBuiltLinux/linux/commit/45c4fb6095d872785e077942da896d65d87ab56b.patch
> > helps?  If you can repro; mind sharing your precise steps to reproduce?
>
> I ran a few tests but the commit that introduced your changes
> passes every time. There's a chance that the bisector got misled
> due to the test runs failing for whatever reason unrelated to the
> patch. There's definitely something introducing a bug somewhere,
> as current mainline/master makes this test fail on this target
> when kernel/configs/debug.config is applied, but it must be
> somewhere else. I'll investigate this some more to see what I can
> find.

Thanks for verifying/reporting.

>
> About the steps to reproduce it, we're using the current KernelCI
> tools (kci_build) to generate the kernel. To actually launch the
> tests I'm submitting jobs to Collabora's LAVA lab, which is
> something that isn't available to external users, so it might be
> a bit hard for you to reproduce the exact environment from the
> original test. If you need to test something, I can do it for
> you.

Shreeya mentioned upthread that `qemu_arm-virt-gicv3-uefi` was
failing, so I assume others should be able to repro in qemu. I'd guess
that LAVA lets you have VMs adjacent to physical hardware.  Having the
qemu command line, kernel config, and perhaps the initramfs are going
to be the three most useful things for any similar bug report.
-- 
Thanks,
~Nick Desaulniers