From: Shreeya Patel <shreeya.patel@collabora.com>
To: "Nick Desaulniers" <ndesaulniers@google.com>,
"Masahiro Yamada" <masahiroy@kernel.org>,
"Greg KH" <gregkh@linuxfoundation.org>,
"Maksim Panchenko" <maks@meta.com>,
"Ricardo Cañuelo" <ricardo.canuelo@collabora.com>
Cc: Michal Marek <michal.lkml@markovi.net>,
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: Tue, 23 May 2023 15:57:06 +0530 [thread overview]
Message-ID: <cff33e12-3d80-7e62-1993-55411ccabc01@collabora.com> (raw)
In-Reply-To: <CAKwvOd=2zAV_mizvzLFdyHE_4OzBY5OVu6KLWuQPOMZK37vsmQ@mail.gmail.com>
Hi Nick and Masahiro,
On 23/05/23 01:22, Nick Desaulniers wrote:
> On Mon, May 22, 2023 at 9:52 AM Greg KH <gregkh@linuxfoundation.org> wrote:
>> On Mon, May 22, 2023 at 12:09:34PM +0200, Ricardo Cañuelo wrote:
>>> On vie, may 19 2023 at 08:57:24, Nick Desaulniers <ndesaulniers@google.com> wrote:
>>>> It could be; if the link order was changed, it's possible that this
>>>> target may be hitting something along the lines of:
>>>> https://isocpp.org/wiki/faq/ctors#static-init-order i.e. the "static
>>>> initialization order fiasco"
>>>>
>>>> I'm struggling to think of how this appears in C codebases, but I
>>>> swear years ago I had a discussion with GKH (maybe?) about this. I
>>>> think I was playing with converting Kbuild to use Ninja rather than
>>>> Make; the resulting kernel image wouldn't boot because I had modified
>>>> the order the object files were linked in. If you were to randomly
>>>> shuffle the object files in the kernel, I recall some hazard that may
>>>> prevent boot.
>>> I thought that was specifically a C++ problem? But then again, the
>>> kernel docs explicitly say that the ordering of obj-y goals in kbuild is
>>> significant in some instances [1]:
>> Yes, it matters, you can not change it. If you do, systems will break.
>> It is the only way we have of properly ordering our init calls within
>> the same "level".
> Ah, right it was the initcall ordering. Thanks for the reminder.
>
> (There's a joke in there similar to the use of regexes to solve a
> problem resulting in two new problems; initcalls have levels for
> ordering, but we still have (unexpressed) dependencies between calls
> of the same level; brittle!).
>
> +Maksim, since that might be relevant info for the BOLT+Kernel work.
>
> Ricardo,
> https://elinux.org/images/e/e8/2020_ELCE_initcalls_myjosserand.pdf
> mentions that there's a kernel command line param `initcall_debug`.
> Perhaps that can be used to see if
> 5750121ae7382ebac8d47ce6d68012d6cd1d7926 somehow changed initcall
> ordering, resulting in a config that cannot boot?
Here are the links to Lava jobs ran with initcall_debug added to the
kernel command line.
1. Where regression happens (5750121ae7382ebac8d47ce6d68012d6cd1d7926)
https://lava.collabora.dev/scheduler/job/10417706
<https://lava.collabora.dev/scheduler/job/10417706>
2. With a revert of the commit 5750121ae7382ebac8d47ce6d68012d6cd1d7926
https://lava.collabora.dev/scheduler/job/10418012
<https://lava.collabora.dev/scheduler/job/10418012>
Thanks,
Shreeya Patel
next prev parent reply other threads:[~2023-05-23 10:27 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-07 4:59 [PATCH v3 0/5] fix debug info for asm and DEBUG_INFO_SPLIT Nick Desaulniers
2022-09-07 4:59 ` [PATCH v3 1/5] x86/boot/compressed: prefer cc-option for CFLAGS additions Nick Desaulniers
2022-09-09 21:05 ` Masahiro Yamada
2022-09-07 4:59 ` [PATCH v3 2/5] Makefile.compiler: Use KBUILD_AFLAGS for as-option Nick Desaulniers
2022-09-09 21:06 ` Masahiro Yamada
2022-09-07 4:59 ` [PATCH v3 3/5] Makefile.compiler: replace cc-ifversion with compiler-specific macros Nick Desaulniers
2022-09-09 21:59 ` Masahiro Yamada
2022-09-07 4:59 ` [PATCH v3 4/5] Makefile.debug: re-enable debug info for .S files Nick Desaulniers
2022-09-07 4:59 ` [PATCH v3 5/5] Makefile.debug: set -g unconditional on CONFIG_DEBUG_INFO_SPLIT Nick Desaulniers
2022-09-09 20:56 ` Masahiro Yamada
2022-09-09 21:02 ` Masahiro Yamada
2022-09-19 17:08 ` [PATCH v4] Makefile.compiler: replace cc-ifversion with compiler-specific macros Nick Desaulniers
2022-09-23 19:44 ` Masahiro Yamada
2022-09-24 14:28 ` Masahiro Yamada
2022-09-25 1:22 ` Masahiro Yamada
2022-09-26 21:41 ` Nick Desaulniers
2023-04-27 11:53 ` Shreeya Patel
2023-04-28 7:41 ` Thorsten Leemhuis
2023-05-02 9:48 ` Shreeya Patel
2023-05-02 11:58 ` Linux regression tracking (Thorsten Leemhuis)
2023-04-28 17:27 ` Nick Desaulniers
2023-05-03 21:02 ` Shreeya Patel
2023-05-03 21:15 ` Nick Desaulniers
2023-05-03 22:33 ` Shreeya Patel
2023-05-15 23:01 ` Nick Desaulniers
2023-05-17 8:34 ` Shreeya Patel
2023-05-17 15:39 ` Ricardo Cañuelo
2023-05-17 16:27 ` Nick Desaulniers
2023-05-18 14:23 ` Ricardo Cañuelo
2023-05-18 21:12 ` Nick Desaulniers
2023-05-19 8:35 ` Ricardo Cañuelo
2023-05-19 15:57 ` Nick Desaulniers
2023-05-22 10:09 ` Ricardo Cañuelo
2023-05-22 16:52 ` Greg KH
2023-05-22 19:52 ` Nick Desaulniers
2023-05-22 20:01 ` Greg KH
2023-05-22 20:16 ` Nick Desaulniers
2023-05-23 10:27 ` Shreeya Patel [this message]
2023-05-23 21:27 ` Nick Desaulniers
2023-06-12 10:10 ` Shreeya Patel
2023-06-20 4:19 ` Masahiro Yamada
2023-07-10 12:09 ` Linux regression tracking (Thorsten Leemhuis)
2023-07-11 11:16 ` Shreeya Patel
2023-08-29 11:28 ` Linux regression tracking (Thorsten Leemhuis)
2023-09-11 10:05 ` Thorsten Leemhuis
2023-09-15 9:33 ` Shreeya Patel
2023-09-30 10:24 ` Masahiro Yamada
2022-09-19 17:30 ` [PATCH v4] Makefile.debug: set -g unconditional on CONFIG_DEBUG_INFO_SPLIT Nick Desaulniers
2022-09-24 1:34 ` Masahiro Yamada
2022-09-19 17:45 ` [PATCH v4] Makefile.debug: re-enable debug info for .S files Nick Desaulniers
2022-09-24 2:11 ` Masahiro Yamada
2022-09-24 2:20 ` Nick Desaulniers
2022-09-24 6:43 ` Masahiro Yamada
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=cff33e12-3d80-7e62-1993-55411ccabc01@collabora.com \
--to=shreeya.patel@collabora.com \
--cc=denys.f@collabora.com \
--cc=gregkh@linuxfoundation.org \
--cc=guillaume.tucker@collabora.com \
--cc=gustavo.padovan@collabora.com \
--cc=kernelci@lists.linux.dev \
--cc=linux-kernel@vger.kernel.org \
--cc=llvm@lists.linux.dev \
--cc=maks@meta.com \
--cc=masahiroy@kernel.org \
--cc=michal.lkml@markovi.net \
--cc=morbo@google.com \
--cc=nathan@kernel.org \
--cc=ndesaulniers@google.com \
--cc=regressions@lists.linux.dev \
--cc=ricardo.canuelo@collabora.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).